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Messages - Ken Feldman

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Policy and solutions / Re: Renewable Energy
« on: November 05, 2019, 08:25:37 PM »
Germany produced more electricity from renewables than coal so far this year.

German Coal Consumption Continues To Crash
By - Nov 04, 2019, 2:30 PM CST Coal Consumption

Lignite and bituminous coal produced 50 percent less energy than renewables in Germany during the first three quarters of 2019, a new report by the Centre for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW) and the German Association of Energy and Water Management (BDEW) reveals.

According to the document, coal generated 125 billion kWh, down from the 171.1 billion kWh produced during the same period last year. Solar, wind and other renewable sources, on the other hand, generated around 183 billion kWh of electricity between Q1 and Q3, 2019, which covered 42.9 percent of gross electricity consumption in the country and represented a 5 percent increase over the same period last year.

Despite Kapferer’s worries, onshore wind power remained the leading source of renewable energy in the Q1-Q3 2019 period, with nearly 72 billion kWh, while offshore wind contributed nearly 17 billion kWh and posted the steepest growth at 31 percent.

Photovoltaics came in second place with around 41 billion kWh, followed by biomass with 33 billion kWh, and hydropower with 16 billion kWh.

Permafrost / Re: Arctic Methane Release
« on: November 05, 2019, 08:19:44 PM »
Igor Semiletov and 65 other scientists on board of a Russian vessel studying the Arctic waters have found that methane in the air over the ESS has up to nine times the global average, research also found that methane jets are shooting up from the seabed to the water’s surface.

I’ve read some comments on this thread that methane doesn’t come up in the bubbles because due microorganisms eats most of the methane.

Has this understanding changed? Is there more methane being released now than in the past to the point that the microorganism are unable to consume most of the methane before it reaches the surface?


The most recent studies still support the fact that most methane is consumed by microbes as it migrates up through the unfrozen sediment that overlays the thawing permafrost layers.  (In some cases, the permafrost is hundreds of meters below the unfrozen sediment, so when you see estimates of huge amounts of methane in permafrost, keep that in mind).  And if the methane is released from areas deeper than 30 meters, it doesn't reach the surface due to chemical reactions with the water.

Here's a link to a pre-published discussion paper from July 2019.  It has a good overview of the current science about methane escape from the ESAS.

Assessing the potential for non-turbulent methane escape from the East Siberian Arctic Shelf
Matteo Puglini, Victor Brovkin, Pierre Regnier, and Sandra Arndt


East Siberian Arctic Shelf (ESAS) hosts large, yet poorly quantified reservoirs of subsea permafrost and associated gas  hydrates.  It  has  been  suggested  the  global-warming  induced  thawing  and  dissociation  of  these  reservoirs  is  currently releasing methane to the shallow shelf ocean and ultimately the atmosphere. However, the exact contribution of permafrost thaw  and  methane  gas  hydrate  destabilization  to  benthic  methane  efflux  from  the  warming  shelf  and  ultimately  methane-climate feedbacks remains controversial. A major unknown is the fate of permafrost and/or gas hydrate-derived methane as it migrates towards the sediment-water interface. In marine sediments, (an)aerobic oxidation reactions generally act as extremely efficient biofilters that often consume close to 100% of the upward migrating methane. However, it has been shown that a number of environmental conditions can reduce the efficiency of this biofilter, thus allowing methane to escape to the overlying ocean. Here, we used a reaction-transport model to assess the efficiency of the benthic methane filter and, thus, the potential for permafrost and/or gas hydrate derived methane to escape shelf sediments under a wide range of environmental conditions encountered on East Siberian Arctic Shelf. Results of an extensive sensitivity analysis show that, under steady state conditions, anaerobic oxidation of methane (AOM) acts as an efficient biofilter that prevents the escape of dissolved methane from shelf sediments  for  a  wide  range  of  environmental  conditions.  Yet,  highCH4 escape  comparable  to  fluxes  reported  from  mud-volcanoes is simulated for rapidly accumulating (sedimentation rate>0.7cm yr−1) and/or active (active fluid flow>6cmyr−1) sediments and can be further enhanced by mid-range organic matter reactivity and/or intense local transport processes, such as bioirrigation. In active settings, high non-turbulent methane escape of up to 19μmolCH4cm−2yr−1can also occur during a transient, multi-decadal period following the sudden onset of CH4 flux triggered by, for instance, permafrost thaw or hydrate destabilization. This "window of opportunity" arises due to the time needed by the microbial community to build up an efficient AOM biofilter. In contrast, seasonal variations in environmental conditions (e.g. bottom water SO2−4,CH4 flux) exert a negligible effect on CH4 efflux through the Sediment-Water Interface (SWI). Our results indicate that present and future methane efflux from ESAS sediments is mainly supported by methane gas and non-turbulent CH4 efflux from rapidly accumulating and/or active sediments (e.g. coastal settings, portions close to river mouths or submarine slumps). In particular active sites on the ESAS may release methane in response to the onset or increase of permafrost thawing or CH4 gas hydrate destabilization rates. Model results also reveal that AOM generally acts as an efficient biofilter for upward migrating CH4 under environmental conditions that are representative for the present-day ESAS with potentially important, yet unquantified implications for the Arctic ocean’s alkalinity budget and, thus, CO2 fluxes. The results of the model sensitivity study are used as a quantitative framework to derive first-order estimates of non-turbulent, benthic methane efflux from the Laptev Sea. We find that, under present day conditions, AOM is an efficient biofilter and non-turbulent methane efflux from Laptev Sea sediments does not exceed 1 GgCH4yr−1. As a consequence, we state that previously published estimates of fluxes from ESAS water into atmosphere cannot be supported by non-turbulent methane escape from the sediments, but require the build-up and preferential escape of benthic methane gas from the sediments to the atmosphere that matches or even exceeds such estimated fluxes.

The "methane fountain" reported on in October was a very rare event.

‘It was a needle in a haystack chase, to find an exact place of a methane seep in dark sea waters, but we found it!

‘This was the most powerful seep I have ever observed. No one has ever recorded anything similar’ said head of the expedition Igor Semiletov, who has participated in 45 Arctic expeditions.

And it was pretty small.

The area of the fountain covered about five metres,

The rest / Re: Who should be the Democratic nominee for President in 2020?
« on: November 01, 2019, 11:50:01 PM »
How can that Buttigieg guy possibly be so high on the list?

He's a centrist who, unlike Biden, can actually put together coherent sentences during a debate.

Permafrost / Re: Arctic Methane Release
« on: November 01, 2019, 11:47:37 PM »
The Barrow NOAA methane data is bizarre.

I note that a spike is not appearing at other sites, yet.

A burp, or the beginning of feedback acceleration?

Or a quality control issue?  Notice that the last few months of data are in orange which means they haven't been validated through quality control yet.

A smooth curve and long-term trend may be fitted to the representative measurements when sufficient data exist. Data shown in ORANGE are preliminary. All other data have undergone rigorous quality assurance and are freely available from GMD, CDIAC, and WMO WDCGG.

Warning: Preliminary data include the this group's most up-to-date data and have not yet been subjected to rigorous quality assurance procedures. Preliminary data viewed from this site are "pre-filtered" using tools designed to identify suspect values. Filtering is performed each time a data set containing preliminary data is requested. Filtering, however, cannot identify systematic experimental errors and will not be used in place of existing data assurance procedures. Thus, there exists the potential to make available preliminary data with systematic biases. In all graphs, preliminary data are clearly identified. Users are strongly encouraged to contact Dr. Pieter Tans, Group Chief ( before attempting to interpret preliminary data.

I provide the attached image of the surface ice elevation for the Thwaites Glacier; which show that there would be a lot of gravitational driving force if an MICI-type of failure mechanism were to be initiated in the Thwaites gateway in the coming decades.

According to DeConto and Pollard (2016), initiation of MICI requires ocean temperatures around Antarctica to be 2 degrees C higher than today and extensive hydrofracturing (caused by surface melt forming melt ponds that drain through the glacier).

As shown upthread, the oceans around Antarctica are warming very slowly (around 0.05 degrees per decade), so it will be centuries before they hit that 2C threashold.

And it appears that surface melt near the Amundsen Sea (where the Thwaites and Pine Island Glaciers terminate) has been low for the past four decades.  The State of the Climate 2018 report, published September 2019, has a chapter on Antarctica covering the most recent full year of observations (2017/2018) and updates trends from previous reports.

Summer sea ice extent in the western Bellingshausen Sea and Amundsen Sea sectors was higher than typical, and was associated with low SSTs and low coastal precipitation. Cool conditions in this sector also contributed to a low ice sheet melt season overall for 2017/18. This low-melt year continues a trend, now spanning from the 1978/79 to 2017/18 seasons, of reduced summer melting that is statistically significant (p < 0.05).

The low melt year of 2017/18 continues a downward trend observed in both melt extent and melt intensity since 1978, trends that are now statistically significant (p < 0.05; Fig. 6.7). Since 1978 melt extent has decreased on average 11 400 km2 per year and the melt index by 294 600 day·km2 per year. Year 2017/18 had the third smallest melt extent and fourth lowest melt intensity in the satellite record (1978–present). These observed negative trends are consistent with previous reports (Liu et al. 2006; Tedesco 2009; Tedesco et al. 2009).

More bad news regarding anthropogenic GHG emissions in the coming decades:

Title: "Fossil Fuel Use in Southeast Asia Is Projected to Increase 60% By 2040"

Extract: "Energy use is projected to increase by half and fossil fuel use is projected to rise by 60 percent. If nothing happens to change this, it will dwarf any reduction in carbon emissions from the developed countries of the West."

Fortunately solar power is now cheaper than coal and natural gas in southeast Asia. Any forecast where you see coal continuing growth past 2025 should be doubt, and now natural gas is in the same situation as coal.

SINGAPORE, Oct 31 (Reuters) - Southeast Asia is accelerating plans to harness energy from the sun in coming years as the cost of generating electricity from some solar power projects has become more affordable than gas-fired plants, officials and analysts said.

The region, where power demand is expected to double by 2040, is striving to expand the share of renewable sources as developing nations seek affordable electricity while battling climate change.

Southeast Asia’s cumulative solar photovoltaic (PV) capacity could nearly triple to 35.8 gigawatt (GW) in 2024 from an estimated 12.6 GW this year, consultancy Wood Mackenzie says.

Among the encouraging signs for the solar industry was a recent auction for a 500 megawatt (MW) solar project in Malaysia of which 365 MW were bid at a price lower than the country’s average gas-powered electricity, said Yeo Bee Yin, minister of energy, science, technology, environment and climate change.

Here's an interesting article about Chinese investments in renewable energy projects around the world.

China Is Bankrolling Green Energy Projects Around the World
By Charlie Campbell / Shanghai

Three distinct renewable energy projects utilizing cutting edge technology in far-flung corners of the globe sharing one uniting characteristic: Chinese finance. Over the past five years, Chinese bankrolling of green energy projects overseas has soared as the world’s number two economy and number one polluter rebrands itself as an environmental champion.

Not only is China today the world’s largest producer of solar panels, wind turbines, batteries and electric vehicles, but it has also been the top investor in clean energy for nine out of the last ten years, according to the Frankfurt School of Finance and Management. Since 2014, Chinese equity investment has supported a total of 12,622 megawatts (MW) of wind and solar projects in South and Southeast Asia alone, according to new research by Greenpeace. That’s the equivalent of 21 standard coal plants or enough to power New York City. The shift from simply exporting to bankrolling green tech—driven by both a drying up of domestic subsidies in China and new incentives to invest abroad—is a boon since “it means China really cares about the future profitability of each project,” says Greenpeace campaigner Liu Junyan.

Chinese export of renewable energy technology around the globe is set to boost Beijing’s clout as the influence of major oil exporters like Russia and Saudi Arabia wanes. China has by far the most renewable energy patents with the U.S., Japan and Europe lagging behind. “No country has put itself in a better position to become the world’s renewable energy superpower than China,” says a recent report by the Global Commission on the Geopolitics of Energy Transformation, chaired by former Iceland President Olafur Grimsson.

The U.S. withdrawal from the Paris Climate Accords under President Donald Trump provided China an opening to seize. America’s abandonment of global leadership on the issue was thrown into sharper focus by Trump’s empty chair during a climate change discussion at August’s G7 meeting in France. “The U.S. administration is not particularly interested in renewables at home let alone overseas,” says Simon Nicholas, an analyst for the Institute for Energy Economics and Financial Analysis. Now, China has firmly established its leading position in renewable energy output, as well as in related technologies such as electric vehicles, transmission lines and battery storage, and Beijing is managing to weaponize green technology in a way that strategic rivals like the U.S. may struggle to counter.

Policy and solutions / Re: Renewable Energy
« on: November 01, 2019, 06:28:16 PM »
Southeast Asia, until recently the last hope for coal exporters, is now one of the fastest growing regions for renewable energy.  The costs for solar power in the region are now cheaper than natural gas.

SINGAPORE (Reuters) - Southeast Asia is accelerating plans to harness energy from the sun in coming years as the cost of generating electricity from some solar power projects has become more affordable than gas-fired plants, officials and analysts said.

Southeast Asia’s cumulative solar photovoltaic (PV) capacity could nearly triple to 35.8 gigawatt (GW) in 2024 from an estimated 12.6 GW this year, consultancy Wood Mackenzie says.
Vietnam leads the pack with a cumulative solar PV installation of 5.5 GW by this year, or 44% of the total capacity in the region, said Rishab Shrestha, Woodmac’s power and renewables analyst. This compares with 134 MW last year.

Among the encouraging signs for the solar industry was a recent auction for a 500 megawatt (MW) solar project in Malaysia of which 365 MW were bid at a price lower than the country’s average gas-powered electricity, said Yeo Bee Yin, minister of energy, science, technology, environment and climate change.

“For the first time in the history of Malaysia we have a large-scale solar energy costs that is less than gas, Yeo said at the Singapore International Energy Week.

Policy and solutions / Re: Renewable Energy
« on: November 01, 2019, 06:23:15 PM »
The price of renewables continue to decrease and wind and solar have achieved grid parity in 66% of the world, including China.

The levelized cost of energy (LCOE) for solar and wind power continues to decline and has already reached parity with wholesale power prices in California, China and parts of Europe, according to the latest report from business intelligence company BloombergNEF (BNEF).

The report illustrates ‘grid parity’ has already been reached in some of the world’s biggest markets as others strive towards the same goal.

According to BNEF’s global benchmark, the cost of electricity produced by solar and onshore wind projects stands at $51 and $47/MWh, respectively – down 11% for solar and 6% for onshore wind from six months ago. Cheaper equipment costs are the main driver behind the latest price falls. The offshore wind LCOE benchmark sits at $78/MWh, down 32% from last year.

Average electricity prices for energy generated by new solar and onshore wind plants have reached parity with average wholesale prices in California and parts of Europe, claim the BNEF analysts. In China, the levelized cost of such energy is now below the average regulated coal power price, the reference price tag in the country.

“This is a three-stage process,” said Tifenn Brandily, an associate in BNEF’s energy economics team and the report’s author. He said phase one concerned the electricity generated by new solar and wind projects becoming cheaper than that produced by new coal and gas plants. In phase two, renewable energy reaches parity with power generated by legacy fossil fuel plants and in phase three, clean energy becomes cheaper than that produced by existing thermal plants. “Our analysis shows that phase one has now been reached for two-thirds of the global population,” said Brandly. “Phase two started with California, China and parts of Europe. We expect phase three to be reached on a global scale by 2030.”

Policy and solutions / Re: Coal
« on: November 01, 2019, 12:25:45 AM »
US Powder River Basin (Montana and Wyoming) coal production is down 42% since 2010.  A 19% decline is projected for next year.  The end could come in the next decade.

Energy Information Administration forecasts quoted by Moody’s suggest that production from the Powder River-dominated Western Region will drop to 339 million short tons in 2020 from 418 million short tons in 2018, a 19% reduction and a 42% decline from 592 million short tons in 2010. Most of that decline happened while coal could still produce electricity more cheaply than renewable alternatives, a situation that’s now reversed. A comparable drop over the coming decade would shutter almost every mine in the basin.

If renewables continue to be installed at current rates in Australia, coal can be phased out by 2040.

In Australia, the world’s second-largest coal exporter after Indonesia, similar trends are afoot. The pipeline of new renewables projects, led by solar farms, now stands at 133 gigawatts, according to research group Rystad Energy. Coupled with a flood of energy-storage projects coming online by 2025, that means that coal-fired generation could be extinct by 2040, the group said Tuesday.

The article includes bad news for coal in Germany and Southeast Asia.  It states that this wasn't foreseen in 2006 when the Stern report was making projections about the costs of mitigating climate change.

The world has gone through a remarkable energy transition over the past decade, but much of the shift still lies, iceberg-like, beneath the surface. Renewables are cheaper than coal almost everywhere, a prospect that was considered so improbable at the time of the 2006 Stern Review on climate change that it wasn’t treated as a serious possibility beyond a vague hope that research and development might one day flip the script.

The worst case emissions scenario used in scientific studies projecting climate change, known as RCP 8.5, assumed that coal use would continue to increase through 2030 and then accelerate through the end of the century.  Fortunately, it looks like that won't happen.

RCP 8.5 on the left vs other RCPs at 2100

Policy and solutions / Re: Renewable Energy
« on: October 31, 2019, 06:36:31 PM »
Purchase Power Agreements (PPAs) are coming to Asia.

Can Southeast Asia quench corporate thirst for renewable energy?

The desire of corporate giants to become 100 per cent renewable is driving clean energy investment and fuelling the energy transition worldwide. As businesses set their sights on greening their operations in Southeast Asia, can the region meet businesses’ clean energy needs?

Clean and green—how are corporates fuelling the energy transition?

Corporate power purchasing agreements (PPAs) have been a key driver of renewable energy infrastructure around the world, especially that of wind and solar. In Asia, where the corporate procurement market is still in its nascent stages compared to Europe and the United States, there has been an uptick in clean energy PPAs, mostly occurring in India.

At a renewable energy conference in Bangkok in June, experts said that while the US has seen the largest uptake of corporate PPAs so far, renewable energy deals are “set to take a significant chunk of the market in Southeast Asia” in the next three to five years as multinational companies with supply chain partners in the region continue to push for clean energy.

According to information from infrastructure industry source Inframation News, corporate procurement of renewable energy is also predicted to rise in Southeast Asia as countries such as the Philippines and Vietnam review their regulations on renewable energy purchasing.

This year, Vietnam’s Ministry of Industry and Trade plans to introduce the Direct Power Purchase Agreement (DPPA) mechanism, a new policy which will allow businesses in Vietnam to purchase from private renewable energy firms.

“People are realising that there are more and more companies that want to buy renewable energy certificates. Since there is money to be made from building a solar plant and selling certificates based on the energy it produces, more players are now motivated to build more renewable energy plants,” he said.

“At the end of the day, assuming the electricity demand is the same, as long as you build one more solar plant, one less fossil fuel plant needs to be built,” Kang said.

Policy and solutions / Re: Oil and Gas Issues
« on: October 31, 2019, 05:49:39 PM »
Is this the beginning of the end for natural gas?

EQT cuts spending on natural gas drilling in 2019, 2020
By Paul J. Gough  – Reporter, Pittsburgh Business Times

EQT Corp. trimmed more than $100 million from its capital budget for this year and will cut it by more than $500 million from its 2020 plan as it works to implement a highly choreographed system of natural gas drilling.

The Pittsburgh-based natural gas driller, which was taken over by a new management team in early July led by Toby Z. Rice, on Thursday provided its first quarterly financial report that took place under the Rice tenure. It also provided a highly anticipated look at what's going on near the drill bit in 2019 and what it plans in 2020. EQT, the country's largest independent natural gas producer, is a bellwether for the Marcellus and Utica shale industries. Early indications see a continued down market for natural gas overall.

Policy and solutions / Re: Direct Air Capture (of Carbon Dioxide)
« on: October 30, 2019, 10:33:08 PM »
Improved agricultural techniques can help restore soil productivity and sequester great amounts of carbon.  Here's an overview of carbon sequestration in soil.

The potential of carbon sequestration in the soil


Soil’s contribution to climate change, through the oxidation of soil carbon, is important. However, soils – and thus agriculture - can play a major role in mitigating climate change. Through multiple agricultural practices, we could help store vast amounts of atmospheric carbon in the soil, while at the same time regenerating soil fertility, plant health and whole ecosystems. This is a no regret option that offers multiple benefits and deserves high-level visibility.

Estimates for carbon sequestration through improved practices vary considerably (Figure 3) as the understanding of the interactions and especially the knowledge of the behavior of soils is still limited. Various studies indicate theoretical potentials of 0.8 to 8 GtC per year 35,40,44,51,53–57, partially including af-/ re-forestation practices, and reaching up to 10 GtC/ yr of additional carbon on agricultural land 41,55, while practically achievable carbon removal amounts are rather located in the lower range of 1.5 to 2.5 GtC/yr 30,53,58. With global carbon emissions in 2016 from fossil fuels and industry of 9.9 GtC plus 1.3 GtC due to land-use changes (such as deforestation)v 38, the potential for carbon sequestration through regenerative agricultural practices looks rather promising, although the implementation of such practices comes with different social, economic and expertise-related and other caveats. It requires funding and collaboration amongst scientists, policymakers, practitioners and multiple other stakeholders. Soil carbon sequestration has a large but not infinite sink capacity, and, importantly, is reversible through bad management. Global efforts to gradually change land use practices are difficult to implement, reducing thus the theoretical mitigation potential

Policy and solutions / Re: Direct Air Capture (of Carbon Dioxide)
« on: October 30, 2019, 10:24:45 PM »
Here's a recent study on Negative Emissions Technologies (NET) needed for the 1.5C and 2C goals.

Negative emissions and international climate goals—learning from and about mitigation scenarios

For aiming to keep global warming well-below 2 °C and pursue efforts to limit it to 1.5 °C, as set out in the Paris Agreement, a full-fledged assessment of negative emission technologies (NETs) that remove carbon dioxide from the atmosphere is crucial to inform science-based policy making. With the Paris Agreement in mind, we re-analyse available scenario evidence to understand the roles of NETs in 1.5 °C and 2 °C scenarios and, for the first time, link this to a systematic review of findings in the underlying literature. In line with previous research, we find that keeping warming below 1.5 °C requires a rapid large-scale deployment of NETs, while for 2 °C, we can still limit NET deployment substantially by ratcheting up near-term mitigation ambition. Most recent evidence stresses the importance of future socio-economic conditions in determining the flexibility of NET deployment and suggests opportunities for hedging technology risks by adopting portfolios of NETs. Importantly, our thematic review highlights that there is a much richer set of findings on NETs than commonly reflected upon both in scientific assessments and available reviews. In particular, beyond the common findings on NETs underpinned by dozens of studies around early scale-up, the changing shape of net emission pathways or greater flexibility in the timing of climate policies, there is a suite of “niche and emerging findings”, e.g. around innovation needs and rapid technological change, termination of NETs at the end of the twenty-first century or the impacts of climate change on the effectiveness of NETs that have not been widely appreciated. Future research needs to explore the role of climate damages on NET uptake, better understand the geophysical constraints of NET deployment (e.g. water, geological storage, climate feedbacks), and provide a more systematic assessment of NET portfolios in the context of sustainable development goals.

The Fifth Assessment Report (AR5) by IPCC Working Group 3 (WG3) provided a good overview of the role of NETs for stringent climate stabilization targets. It highlighted that many 2 °C scenarios entail large-scale deployment of NETs after 2050 to compensate for residual CO2 emissions from sectors that are difficult to decarbonize, such as industry and aviation. It warned that these scenarios are mostly associated with a temporary overshoot of the climate goal and that delays in climate action and limitations in the availability of NETs can render the 2 °C goal infeasible. It also emphasized the challenges (e.g. societal concerns), risks (e.g. technological availability, biodiversity, water, food prices, inter-generational impacts) and uncertainties (e.g. geological storage, large bioenergy production) surrounding these technologies (see also Electronic Supplementary Material (ESM) for a complete review of NET statements in AR5).

Yet, the analysis of NETs in WG3 AR5 remained inaccessible because findings were scattered in various sections and sub-sections of the report (i.e. in Chaps. 2, 6, 7, 11, 13).

The recent IPCC Special Report on Global Warming of 1.5 °C (SR1.5) (IPCC 2018) filled this gap by drawing upon a set of recent reviews (Minx et al. 2018; Fuss et al. 2018; Nemet et al., 2018) that used formal methods of evidence synthesis. It further added a comprehensive analysis on the role of NETs in 1.5 °C scenarios based on newly emerging evidence. The report highlighted that all 1.5 °C scenarios with limited or no overshoot require NETs on the order of 100–1000 GtCO2 over the twenty-first century but that significant near-term emissions reductions (e.g. low energy demand, low material consumption, low GHG-intensive food consumption) can limit NET deployment to a few hundred GtCO2 without reliance on Bioenergy with Carbon Capture and Storage (BECCS). It also called attention to the lack of published pathways featuring NETs other than afforestation and reforestation (AR) and BECCS (see also Electronic Supplementary Material (ESM) for a complete review of NET statements in Fuss et al. 2018, IPCC 2018 and Rogelj et al. 2018b).

Policy and solutions / Re: Renewable Energy
« on: October 30, 2019, 10:14:48 PM »
USA Natural Gas

The IPCC reports say man has to significantly reduce CO2 emissions by 2030, starting after 2020.

Let's look at Ken's timetable, which looks very possible to me.

Transportation - only 3 %
expect natural gas to be out of the transportation sector by 2040.
Electrical generation - 36%
For electrical generation, renewables plus batteries are already cheaper than peaker plants.  Current projections have them being cheaper than operating natural gas by the mid-2030s. So expect natural gas to be completely out of the electrical generation sector by 2050.
Residential and Commercial  Heating - 29 %
Look for natural gas to disappear from building heating and other uses (cooking, laundries, etc...) by the 2050s, possibly even earlier,
Industry 30%

No timetable given

If we only had time...?

Here's what the IPCC Special Report: Global Warming of 1.5C (published in 2018) states:

In model pathways with no or limited overshoot of 1.5°C, global net anthropogenic CO2 emissions decline by about 45% from 2010 levels by 2030 (40–60% interquartile range), reaching net zero around 2050 (2045–2055 interquartile range). For limiting global warming to below 2°C 12CO2 emissions are projected to decline by about 25% by 2030 in most pathways (10–30% interquartile range) and reach net zero around 2070 (2065–2080 interquartile range). Non-CO2 emissions in pathways that limit global warming to 1.5°C show deep reductions that are similar to those in pathways limiting warming to 2°C. (high confidence) (Figure SPM.3a) {2.1, 2.3, Table 2.4}

Keeping warming under 2C without negative emissions technologies (NET) is still possible.  To meet the 1.5C goal, it looks like large scale deployment of NET will be required.  Even if we overshoot, we can draw carbon out of the atmosphere.

Negative emissions and international climate goals—learning from and about mitigation scenarios

For aiming to keep global warming well-below 2 °C and pursue efforts to limit it to 1.5 °C, as set out in the Paris Agreement, a full-fledged assessment of negative emission technologies (NETs) that remove carbon dioxide from the atmosphere is crucial to inform science-based policy making. With the Paris Agreement in mind, we re-analyse available scenario evidence to understand the roles of NETs in 1.5 °C and 2 °C scenarios and, for the first time, link this to a systematic review of findings in the underlying literature. In line with previous research, we find that keeping warming below 1.5 °C requires a rapid large-scale deployment of NETs, while for 2 °C, we can still limit NET deployment substantially by ratcheting up near-term mitigation ambition. Most recent evidence stresses the importance of future socio-economic conditions in determining the flexibility of NET deployment and suggests opportunities for hedging technology risks by adopting portfolios of NETs. Importantly, our thematic review highlights that there is a much richer set of findings on NETs than commonly reflected upon both in scientific assessments and available reviews. In particular, beyond the common findings on NETs underpinned by dozens of studies around early scale-up, the changing shape of net emission pathways or greater flexibility in the timing of climate policies, there is a suite of “niche and emerging findings”, e.g. around innovation needs and rapid technological change, termination of NETs at the end of the twenty-first century or the impacts of climate change on the effectiveness of NETs that have not been widely appreciated. Future research needs to explore the role of climate damages on NET uptake, better understand the geophysical constraints of NET deployment (e.g. water, geological storage, climate feedbacks), and provide a more systematic assessment of NET portfolios in the context of sustainable development goals.

Conservation agriculture and regenerative agriculture are spreading rapidly, and they have the potential to sequester hundreds of billions of tons of carbon while improving soil conditions and increasing food production.  In the US, "Big Food" is actively funding regenerative agriculture to protect it's future revenue streams.

General Mills, the packaged food giant, is one of several Big Food corporations jumping on the regenerative agriculture bandwagon, escalating the buzz around the idea that capturing carbon in the soil could reverse climate change. The company took the lead when it announced this spring that it would apply regenerative agriculture to 1 million acres by 2030 — about a quarter of the land from which it sources ingredients in North America.

Undisturbed soil naturally contains carbon and microbes, but once it's tilled for farming, for instance, the carbon is released into the air. Regenerative agriculture, a term that is often used synonymously with “carbon farming,” is a set of practices that builds organic matter back into the soil, effectively storing more water and drawing more carbon out of the atmosphere. Examples include applying compost and employing managed grazing, as well as planting cover crops, which protect the soil in winter and prevent erosion while adding nutrients. Though scientists generally agree the practices, especially when used together, work to draw more carbon, there’s an ongoing debate on how much carbon can be stored that way and for how long.

One much-cited estimate of potential soil sequestration published to date suggests that if regenerative practices were used on all of the world’s croplands and pastures forever — a huge assumption — the soil may be able to sequester up to 322 billion tons of carbon dioxide from the atmosphere.

We're getting pretty far off the topic of renewable energy here though.  Maybe we should take this up in the Direct Air Capture topic.

Policy and solutions / Re: Nuclear Power
« on: October 30, 2019, 09:53:22 PM »
I did not realise that the USA have currently 97 nuclear power plants in operation (100 in 2016) according to the EIA, currently operating at just under 75% of operating capacity and generating around 18% of total electricity production.

97 installations where everybody knows what they are doing?

A few years ago, it was 105.  However, nuclear is the most expensive way to generate electricity, so it's being phased out.  A few States have passed laws that subsidize existing nuclear power plants to prevent them from closing early and the expense of decommissioning them is so large that many continue to operate just to generate some revenues and put off those decommissioning costs for a few more years.

The last major incident in the US was at Three Mile Island more than 40 years ago but it seems like there are "minor" incidents or near misses every month.  This article about a "minor mishap" in South Carolina is typical.

Nuclear workers hospitalized; Columbia plant runs afoul of safety rules - again
By Sammy Fretwell
October 22, 2019 10:56 AM, Updated October 22, 2019 11:23 AM

A Columbia nuclear fuel factory with a history of leaks, spills and other mishaps has again run into trouble, this time after three workers went to the hospital and an inspection found the plant didn’t have proper safety equipment.

The Westinghouse nuclear plant discovered last week that it had a device in place that was not adequate to prevent uranium from leaking into chemical supply drums at the site, federal records show.

That’s potentially significant because the drums were in a “non-favorable’’ position, which under certain circumstances could increase chances of a radiation burst inside the 1,000-employee plant.

Nothing to see here, move along.

As more research is done into the MICI failure mechanism, it seems less plausible.  The following two papers, published in the past 10 days, would seem to doom the MICI hypothesis.

A Speed Limit on Ice Shelf Collapse through Hydrofracture
Alexander A. Robel  Alison F. Banwell
First published: 24 October 2019

Increasing surface melt has been implicated in the collapse of several Antarctic ice shelves over the last few decades, including the collapse of Larsen B Ice Shelf over a period of just a few weeks in 2002. The speed at which an ice shelf disintegrates strongly determines the subsequent loss of grounded ice and sea level rise, but the controls on collapse speed are not well understood. Here we show, using a novel cellular automaton model, that there is an intrinsic speed limit on ice shelf collapse through cascades of interacting melt pond hydrofracture events. Though collapse speed increases with the area of hydrofracture influence, the typical flexural length scales of Antarctic ice shelves ensure that hydrofracture interactions remain localized. We argue that the speed at which Larsen B Ice Shelf collapsed was caused by a season of anomalously high surface meltwater production.

It's important to note that the collapse of an ice shelf takes weeks, not hours, as that allows time for the resultant ice cliff to flow viscously to height below which brittle failure would occur.

Marine Ice Cliff Instability Mitigated by Slow Removal of Ice Shelves
Fiona Clerc  Brent M. Minchew  Mark D. Behn
First published: 21 October 2019

The accelerated calving of ice shelves buttressing the Antarctic Ice Sheet may form unstable ice cliffs. The marine ice‐cliff instability (MICI) hypothesis posits that cliffs taller than a critical height (~90‐m) will undergo structural collapse, initiating runaway retreat in ice‐sheet models. This critical height is based on inferences from pre‐existing, static ice cliffs. Here we show how critical height increases with the timescale of ice‐shelf collapse. We model failure mechanisms within an ice cliff deforming after removal of ice‐shelf buttressing stresses. If removal occurs rapidly, the cliff deforms primarily elastically and fails through tensile‐brittle fracture, even at relatively small cliff heights. As the ice‐shelf removal timescale increases, viscous relaxation dominates, and the critical height increases to ~540 m for timescales > days. A 90‐m critical height implies ice‐shelf removal in under an hour. Incorporation of ice‐shelf collapse timescales in prognostic ice‐sheet models will mitigate MICI, implying less ice‐mass loss.

Policy and solutions / Re: Renewable Energy
« on: October 30, 2019, 08:00:25 PM »
As we discussed in the oil and gas forum, there are renewable solutions for all of those natural gas uses.

What you say is of course correct, Ken.

What do you think is the timeframe until all sectors are converted to a CO2 emissions-free technology?

For transportation, most of the natural gas is used for compressors in pipelines that transport fossil fuels.  As fossil fuel use declines, this use for natural gas will disappear.  I expect that we will need far fewer pipelines for natural gas, gasoline and crude oil by 2050.  I don't know how long they last, but it's hard to foresee any new pipelines being built after 2030 as natural gas use peaks and declines due to alternatives being cheaper.

For vehicles, the primary users of natural gas are buses.  The infrastructure for compressed natural gas is expensive and there's the annoying tendency for CNG tanks to explode that deters new investments in them.  Also, batteries have become better and electric vehicles are expected to be cheaper than alternatives in the early 2020s.  Many transit systems have already begun to transition to battery electric vehicles instead of CNG.  As buses can last 12 to 15 years, and some CNG buses are still being made now, expect natural gas to be out of the transportation sector by 2040.

For electrical generation, renewables plus batteries are already cheaper than peaker plants.  Current projections have them being cheaper than operating natural gas by the mid-2030s. So expect natural gas to be completely out of the electrical generation sector by 2050.

Almost half of the buildings that will be in use in 2100 haven't been built yet.  This is probably an underestimate as large portions of the population live in areas where sea-level rise (and other flooding from more intense precipitation) will force them to move.  As more people transition off of natural gas the costs of maintaining the existing infrastructure will be shared by fewer customers, causing the prices to increase.  Look for natural gas to disappear from building heating and other uses (cooking, laundries, etc...) by the 2050s, possibly even earlier, due to the combination of increased costs (even if carbon taxes aren't imposed) and outright bans at the State and local level.

Here's an article about how long buildings last.  Keep in mind that even if the frame of the building lasts for 100s of years, the electrical, heating, roofing and appliances will be replaced when they wear out.

Maintenance and up-grading
Older homes will generally have had their roofs replaced, new heating and air-conditioning systems installed, bathrooms and kitchens remodeled and plumbing and electrical systems upgraded. However, their basic structural bones, the foundation, footings and framing are basically the same. In areas with earthquakes and high winds owners may have reinforced the structural components to help withstand these forces.

Condo complexes, apartment buildings and high-rise structures often have shorter life spans than single family homes

The basic reason for this is that as components and various systems, such as plumbing, HVAC system, electrical systems and large dual pane windows become worn out or obsolete; and they cost more to replace or update than the value or wroth added. Imagine high rise buildings with large glass facades and dual pane windows where the large insulated  glass panels have began to fail, where they have become foggy, internally streaked and have lost their insulation value which is not unusual after 20 or 30 years. Now think of the cost to replace and upgrade these windows and cladding; it can be astronomically expensive.

These type of buildings may last only 1/2 half or 2/3 as long a single family home and may be torn down

Here's an article about cities banning new natural gas hookups:

When Berkley, California recently made the announcement that it would become the first city in the United States to ban natural-gas installations in newly constructed buildings, public took note. After the news broke, four other California cities established new rules to "encourage buildings to use only electricity," according to a report from Salon. Since then, more cities, such as Santa Monica, San Jose, and Menlo Park have made the change, as well. Several larger California cities are seriously considering such a ban, as are more far-flung cities like Seattle and Brookline, Massachusetts. However, why is there still a group of individuals against this proactive approach to helping mitigate better carbon cutting practices?

Nathaneal Johnson of Salon highlights, "The Berkeley ban outlaws gas in new single family homes starting in January. It will apply to the construction of larger buildings as soon as state regulators put the finishing touches on standards for all-electric buildings. Most of the other cities that have passed ordinances are taking a more moderate approach.

All of these estimated times could be significantly accelerated if a carbon tax were imposed.  It seems like the public is becoming more aware of urgency of reducing our emissions and more politicians are embracing the idea of a carbon tax, or at least a cap and trade system, so it's possible that there could be one in the US in the 2020s.  But even without action at the Federal level, I don't foresee (fossil) natural gas being used in any significant amounts in the later half of this century.

There is also a lot of confusion on this whole website about the RCP scenarios used to make future projections.  The most alarming studies use RCP 8.5 to get their alarming results and they tend to downplay the benefits of limiting emissions to the RCP 2.6 scenario.

People look at emissions today and think they will continue on at the same rate into the future without taking into account recent advancements in renewable energy and battery technology.  (Keep in mind that the bulk of emissions projected for the 21st century occur after 2030.)  Here is a study that explains the assumptions in the RCP 8.5 scenario:

A growing population and economy combined with assumptions about slow improvements of energy efficiency lead in RCP8.5 to a large scale increase of primary energy demand by almost a factor of three over the course of the century (Fig. 5). This demand is primarily met by fossil fuels in RCP 8.5. There are two main reasons for this trend. First, the scenario assumes consistent with its storyline a relatively slow pace for innovation in advanced non-fossil technology, leading for these technologies to modest cost and performance improvements (e.g., learning rates for renewables are below 10% per doubling of capacity; see also Riahi et al. 2007 for further detail). Fossil fuel technologies remain thus economically more attractive in RCP8.5. Secondly, availability of large amounts of unconventional fossil resources extends the use of fossil fuels beyond presently extractable reserves (BP 2010). The cumulative extraction of unconventional fossil resources lies, however, within the upper bounds of theoretically extractable occurrences from the literature (Rogner 1997; BGR 2009; WEC 2007).9

Notice that coal makes up most of the projected energy use in RCP8.5.  In RCP 8.5, coal use is projected to increase significantly in 2030 and continue strong growth until 2100.

In reality, wind and solar power have already become cheaper than coal and coal use is expected to peak by 2030 (and possibly even earlier) as the following article, published in August 2019 explains:

China's coal demand to peak around 2025, global usage to follow: report

BEIJING (Reuters) - China’s coal demand will start to fall in 2025 once consumption at utilities and other industrial sectors reaches its peak, a state-owned think tank said in a new report, easing pressure on Beijing to impose tougher curbs on fossil fuels.

The world’s biggest coal consumer is expected to see total consumption fall 18% from 2018 to 2035, and by 39% from 2018 to 2050, the CNPC Economics and Technology Research Institute, run by the state-owned China National Petroleum Corp (CNPC), forecast in a report on Thursday.

However, the CNPC researchers said they expected the total share of coal to drop to 40.5% by 2035 as renewable, nuclear and natural gas capacity continues to increase rapidly.
“With coal demand in China falling gradually, world coal consumption is forecast to reach a peak within 10 years. Meanwhile, China’s coal demand, currently accounting for half of the world’s total, will decline to around 35% by 2050,” the report said.

Wind and solar continue to fall in cost and are now approaching parity with natural gas.

09.11.19 world changing ideas

It’s now cheaper to build new renewables than it is to build natural gas plants
People could save $29 billion on their electric bills if utilities built new clean energy instead of new natural gas plants.

By Adele Peters  2 minute Read
Clean energy has reached a tipping point: It’s now cheaper to build and use a combination of wind, solar, batteries, and other clean tech in the U.S. than to build most proposed natural gas plants. Utilities want to spend $90 billion to build new gas plants and $30 billion to build new gas pipelines—but if they used renewables instead, consumers could save $29 billion in electricity bills, according to a new report from the nonprofit Rocky Mountain Institute.

The researchers looked at how natural gas plants are used on power grids today and then calculated what would be necessary for clean energy to replace those plants, including batteries to store power when wind and solar aren’t available. It’s already cheaper, in almost all cases, to build and run new clean energy projects than natural gas projects. By the middle of the 2030s, clean energy could drop in cost so much that it will be cheaper to build and run new renewables than to keep existing gas plants running, and gas plants could quickly become stranded assets (the same thing is currently happening with coal plants around the country). More than 90% of recently built plants could be forced into early retirement.

Policy and solutions / Re: Coal
« on: October 30, 2019, 06:08:52 PM »
Coal bankruptcies are creating a ponzi scheme where the last people to invest in the assets will be left holding the bag.  Utilities are continuing to move up the dates of plant retirements to take advantage of cheaper renewables.  The only thing stopping us from retiring most coal plants now is that it will take years to build the new renewable plants to replace them.

Duke Energy Corp. is one of the largest coal burners in America. But the North Carolina-based utility’s coal fleet is running less and less, an E&E News review of federal data shows.
In a sign of mounting economic distress, nine of the company’s 13 coal plants ran less than half the year in 2018. Eight of those facilities averaged annual run times of less than 50% between 2014 and 2018. Only two of the company’s coal facilities produced more electricity in 2018 than they did five years earlier.

Duke has started to close more coal plants in response. On Monday, the utility filed a plan with North Carolina regulators that moved up the retirement dates of three coal units. That followed a release of its plan with Indiana regulators in June that advanced the closure of seven coal units there.

For the first time, Pacific Northwest and Rocky Mountain utility PacifiCorp is planning to rely on massive amounts of solar PV and batteries, as well as wind power, for a large share of its long-term energy needs. The company also wants to shut down economically struggling coal plants years earlier than scheduled.

The draft IRP would close five coal plants in Wyoming by 2028, instead of keeping most of them open through 2037 or later.

The utility expects to see significant savings over the 20 years covered by its IRP, compared to various business-as-usual benchmarks used in its previous analyses. Its most recent analysis indicated that it could save nearly $600 million over 20 years, largely by replacing coal-fired power with low-cost renewables.

I could post a lot more articles like this, but this post is already getting long.

Policy and solutions / Re: Renewable Energy
« on: October 30, 2019, 05:59:12 PM »
Cross-post from oil & gas of a post by me - Ken Feldman doesn't see a problem - I do.

What do you think?

USA Natural Gas Consumption

There has been much analysis of how solar & wind are becoming cheaper than natural gas for electricity generation


In the US of A only just over one-third (36%) of natural gas consumed is used for electricity generation.
The rest is mainly used for:-
- heating homes - 17%
- heating commercial premises - 12%
- heating in industrial processes - 33%
- transportation - 3% (??)

When what you want is to use heat directly - gas is cheap as chips. Renewables can't compete.

Without a carbon tax I don't see how this will be solved.

As we discussed in the oil and gas forum, there are renewable solutions for all of those natural gas uses.

The primary one is electrification.  That will take care of transportation and some of the heating uses.  See the EV and Trucks... fora for more about those topics.

Heat pumps have become much more efficient in recent years and can replace the commercial and residential heating done currently by natural gas.  In fact, cities are starting to ban the use of natural gas for new homes and buildings because better alternatives exist.  Here is a link to an introduction on heat pumps:

The most common type of heat pump is the air-source heat pump, which transfers heat between your house and the outside air. Today's heat pump can reduce your electricity use for heating by approximately 50% compared to electric resistance heating such as furnaces and baseboard heaters. High-efficiency heat pumps also dehumidify better than standard central air conditioners, resulting in less energy usage and more cooling comfort in summer months. Air-source heat pumps have been used for many years in nearly all parts of the United States, but until recently they have not been used in areas that experienced extended periods of subfreezing temperatures. However, in recent years, air-source heat pump technology has advanced so that it now offers a legitimate space heating alternative in colder regions.

Geothermal (ground-source or water-source) heat pumps achieve higher efficiencies by transferring heat between your house and the ground or a nearby water source. Although they cost more to install, geothermal heat pumps have low operating costs because they take advantage of relatively constant ground or water temperatures. Geothermal (or ground source) heat pumps have some major advantages. They can reduce energy use by 30%-60%, control humidity, are sturdy and reliable, and fit in a wide variety of homes. Whether a geothermal heat pump is appropriate for you will depend on the size of your lot, the subsoil, and the landscape. Ground-source or water-source heat pumps can be used in more extreme climates than air-source heat pumps, and customer satisfaction with the systems is very high.

Finally, to replace fossil natural gas uses as industrial or chemical feedstock, the byproducts of biochar can be used.  Biochar is an excellent fertilizer and soil conditioner that is seeing increasing use around the world.

Rob DeConto was a contributing author on the IPCC's 2019 Special Report on the Oceans and the Cryosphere (SROCC)  Chapter 4 is dedicated to analyzing the recent studies on sea level rise.  It includes a good overview of MICI, MISI, the role of subsurface water in contact with the floating ice shelves and the importance of grounding line retreat.  They have paragraphs dedicated to analyzing recent observations for Thwaites and Pine Island Glaciers as well as overall assessments of both the Greenland and Antarctic ice sheets.  Here's a link to chapter 4 of the SROCC:

Atmospheric forcing is also become increasingly recognized to be an important factor for the future of the AIS. A sustained (15 days) melt event over the Ross Sea sector of the WAIS in 2016 illustrated both the connectivity of Antarctica to the tropics and El Niño, and the possibility that future meltwater production on ice-shelf surfaces could change in the near future (Nicolas et al., 2017). This was highlighted by Trusel et al. (2015), who evaluated the future expansion of surface meltwater using the snow component in the RACMO2 regional atmospheric model (Kuipers Munneke et al., 2012) and output from CMIP5 GCMs. Under RCP8.5, they find a substantial expansion of surface meltwater production on ice shelves late in the 21st century that exceed melt rates observed before the 2002 collapse of the Larsen B Ice Shelf. Surface meltwater is important for both ice dynamics and SMB due to its potential to reduce albedo, saturate the firn layer, deepen surface crevasses, and to cause flexural stresses that can contribute to ice-shelf break-up (hydrofracturing) (Banwell et al., 2013; Kuipers Munneke et al., 2014). The presence of surface meltwater does not necessarily lead to immediate ice shelf collapse (Bell et al., 2017b; Kingslake et al., 2017), although surface meltwater was a precursor on ice shelves which have collapsed (Scambos et al., 2004; Banwell et al., 2013). This dichotomy illustrates the uncertain role of meltwater and the need for additional study. When and if melt rates will be sufficiently high in future warming scenarios to trigger widespread hydrofracturing is a key question, because the loss of ice shelves is associated with the onset of marine ice sheet instabilities (Crosschapter Box 8 in Chapter 3). Based on the single modelling study by Trusel et al. (2015), we do not expect that widespread ice shelf loss will occur before the end of the 21st century, but due to limited observations and modelling to date, we have low confidence in this assessment.

DeConto and Pollard (2016) used an ice sheet model with a formulation similar to that used by Golledge et al. (2015) and Bulthuis et al. (2019) but they include glaciological processes not accounted for in other continental-scale models: 1) surface melt and rain water influence on hydrofracturing of ice shelves; and 2) brittle failure of thick, marine-terminating ice fronts that have lost their buttressing ice shelves. Where the ice fronts are thick enough to form tall ice cliffs above the waterline, they can produce stresses exceeding the strength of the ice, causing calving (Bassis and Walker, 2012). Once initiated, ice-cliff calving has been hypothesized to produce a self-sustaining Marine Ice Cliff Instability (MICI; Cross-chapter Box 8, Chapter 3). The validity of MICI remains unproven (Edwards et al., 2019) and is considered to be characterized by deep uncertainty, but it has the potential to raise GMSL faster than MISI. DeConto and Pollard (2016) represent hydrofracturing and ice-cliff calving with simple parameterizations, but the glaciological processes themselves are supported by more detailed modelling and observations (Scambos et al., 2009; Banwell et al., 2013; Ma et al., 2017; Wise et al., 2017; Parizek et al., 2019). DeConto and Pollard (2016) provide four ensembles for RCP2.6, RCP4.5, and RCP8.5 scenarios, representing two alternative ocean model treatments and two alternative paleo sea-level targets used to tune their model physical parameters. However, their ensembles do not explore the full range of model parameter space or provide a probabilistic assessment (Kopp et al., 2017; Edwards et al., 2018). Under RCP2.6, DeConto and Pollard (2016) find very little GMSL rise from Antarctica by 2100 (0.02–0.16 m), consistent with the findings of Golledge et al. (2015) and Bulthuis et al. (2019). In contrast, their four ensemble means range between 0.26–0.58 m for RCP4.5, and 0.64–1.14 m for RCP8.5.

Note that these are the estimates from their 2016 study. They've since indicated that they are considerable over estimates.

There are summaries of many other studies in the chapter, including ones that address the recently discovered cavity under Thwaites Glacier.  They also address the feedbacks from huge increases in meltwater on ocean stratification.

None of the scenarios lead to the catastrophic consequences implied by AbruptSLR's musings.  All of them agree that if we can keep emissions in-line with the RCP 2.6 scenario, the future sea level rise is greatly reduced from the RCP 8.5 emissions scenarios.  Many agree (including DeConto and Pollard) that the WAIS will not collapse under the RCP 2.6 scenario.

Policy and solutions / Re: Renewable Energy
« on: October 29, 2019, 09:15:52 PM »
Cross posted from the Oil and Gas issues forum.

Forbes (a conservative news site in the US that focuses on business issues) published this story today:

Huge Battery Investments Drop Energy-Storage Costs Faster Than Expected, Threatening Natural Gas

The global energy transition is happening faster than the models predicted, according to a report released today by the Rocky Mountain Institute, thanks to massive investments in the advanced-battery technology ecosystem.

Previous and planned investments total $150 billion through 2023, RMI calculates—the equivalent of every person in the world chipping in $20. In the first half of 2019 alone, venture-capital firms contributed $1.4 billion to energy storage technology companies.

“These changes are already contributing to cancellations of planned natural-gas power generation,” states the report. “The need for these new natural-gas plants can be offset through clean-energy portfolios (CEPs) of energy storage, efficiency, renewable energy, and demand response.”

New natural-gas plants risk becoming stranded assets (unable to compete with renewables+storage before they’ve paid off their capital cost), while existing natural-gas plants cease to be competitive as soon as 2021, RMI predicts.

Policy and solutions / Re: Oil and Gas Issues
« on: October 29, 2019, 09:12:09 PM »
Since electrification is a key tool in eliminating the use of natural gas, it's important to keep up with the latest developments.  This story was published in Forbes (a conservative media site) today:

Editor's Pick48,188 viewsOct 29, 2019, 12:00am
Huge Battery Investments Drop Energy-Storage Costs Faster Than Expected, Threatening Natural Gas

The global energy transition is happening faster than the models predicted, according to a report released today by the Rocky Mountain Institute, thanks to massive investments in the advanced-battery technology ecosystem.

Previous and planned investments total $150 billion through 2023, RMI calculates—the equivalent of every person in the world chipping in $20. In the first half of 2019 alone, venture-capital firms contributed $1.4 billion to energy storage technology companies.

“These investments will push both Li-ion and new battery technologies across competitive thresholds for new applications more quickly than anticipated,” according to RMI. “This, in turn, will reduce the costs of decarbonization in key sectors and speed the global energy transition beyond the expectations of mainstream global energy models.”

New natural-gas plants risk becoming stranded assets (unable to compete with renewables+storage before they’ve paid off their capital cost), while existing natural-gas plants cease to be competitive as soon as 2021, RMI predicts.

Policy and solutions / Re: Oil and Gas Issues
« on: October 29, 2019, 09:07:35 PM »
My post intended to point out that replacing natural gas with renewables for electricity generation will be the easy bit.

The other 64% is the hard bit.

So not much point in recycling the known data on the reducing cost of renewable electricity.

There are many replacements for those uses.  Most (like building heating) can actually be replaced by electricity and when renewable prices are cheaper than gas, the economic incentive will be there for widespread electrification of those uses.  In addition, heat pumps will also become more common for building heating.

Biochar, which is a fertilizer replacement and soil conditioner, produces renewable natural gas as a bi-product.  It can substitute for natural gas in chemical applications, including industrial feedstocks.

In transportation, compressed natural gas is used for buses, forklifts and other specialized transportation uses.  It's pretty costly compared to alternatives due to the need to compress the gas and it's basically dying out now.  It will be replaced by battery electric vehicles.

Policy and solutions / Re: Oil and Gas Issues
« on: October 29, 2019, 08:03:50 PM »
A carbon tax would certainly help speed the transition, but renewables are already cheaper than peaker natural gas plants.  And the cost of renewables is decreasing rapidly.  They're projected to be cheaper than operating natural gas plants within a decade or two.

And finally, despite record production of natural gas and its current low price, reports indicate that renewable energy is about to become a formidable competitor in cost.

The last point received an exclamation point last month in two groundbreaking reports from the Rocky Mountain Institute (RMI). Its researchers found that America has reached "a historic tipping point" where "combinations of solar, wind, storage, efficiency and demand response are now less expensive than most proposed gas power plant projects," and will undercut the operating costs of existing gas plants within the next 10 to 20 years.

Bloomberg New Energy Finance says that by 2030, "new wind and solar ultimately get cheaper than running existing coal or gas plants almost everywhere." An analysis by Lazard Asset Management that found that the range of unsubsidized levelized costs of onshore wind and utility-scale solar to be below that of natural gas.
The federal Energy Information Administration has estimated that by 2023, the levelized cost of producing power by onshore wind and solar, will be considerably cheaper than natural gas ($36.60, $37.60 and $40.20 per megawatt hour respectively for each energy source). Levelized costs reflect construction and operation costs over the technology's assumed lifetime, including subsidies, which solar and wind currently enjoy.

The growing gap between ever-cheaper renewables and natural gas means that some 71 percent of planned new gas capacity analyzed by RMI could become uneconomic by 2035, potentially resulting in tens of billions of dollars of silent hulks otherwise known as stranded assets. If new pipelines were built, they are likely to become underutilized almost overnight as the amount of gas flowing through them plummets 20 to 60 percent over the next 16 years, depending on the region.

Policy and solutions / Re: Renewable Energy
« on: October 29, 2019, 07:57:40 PM »
Even the IEA, notorious for consistently underestimating the growth of renewables, is projecting tremendous growth for them.  They recently released a report that indicates renewables could generate all of the world's electricity by the 2040s.

Offshore Wind Power Could Produce More Electricity Than World Uses, says International Energy Agency

Common Dreams Oct. 28, 2019 10:41AM EST

A new report from the International Energy Agency released Friday claims that wind power could be a $1 trillion business by 2040 and that the power provided by the green technology has the potential to outstrip global energy needs.

The IEA finds that global offshore wind capacity may increase 15-fold and attract around $1 trillion of cumulative investment by 2040. This is driven by falling costs, supportive government policies and some remarkable technological progress, such as larger turbines and floating foundations. That's just the start—the IEA report finds that offshore wind technology has the potential to grow far more strongly with stepped-up support from policy makers.

It would take a major infrastructural commitment to develop wind power to the point that the renewable energy resource could take over the majority of global energy needs, but it's not impossible. As The Guardian pointed out Friday, "if windfarms were built across all useable sites which are no further than 60km (37 miles) off the coast, and where coastal waters are no deeper than 60 metres, they could generate 36,000 terawatt hours of renewable electricity a year."

"This would easily meeting the current global demand for electricity of 23,000 terawatt hours," added The Guardian.

Policy and solutions / Re: Renewable Energy
« on: October 29, 2019, 07:52:08 PM »


Great charts.

Keep in mind that renewables only became cheaper than fossil fuels in the past couple of years.  Most of the investment decisions made for power plants coming on line today were made before that point.  Now that solar and wind are cheaper, the curve should rise exponentially.

Policy and solutions / Re: Alaska Coal and Warming
« on: October 29, 2019, 06:31:54 PM »
In order to export coal from Alaska, there would need to be new ports, rail lines and other infrastructure built, costing hundreds of millions of dollars.  It's difficult to see anyone investing in that while other exporters and miners in the "lower 48" are going bankrupt.

US thermal coal production cuts and consolidation expected as export and domestic markets remain weak: analysts

Houston — Although the seaborne thermal coal market had a slight price rebound during the third quarter, US exports are expected to remain low this year, forcing more production cuts and consolidation as the domestic market remain bearish as well, analysts said this week.

Despite the slight third-quarter price rebound in the CIF ARA market, "we estimate that most US exports are still not economical at current spot prices," B Riley FBR analysts Lucas Pipes, Matthew Key and Daniel Day wrote, noting dampened seaborne thermal coal demand due to a "sharp rise" in European carbon allowance prices and cheap natural gas and imported LNG.

However, according to Fitch Solutions, "we do not expect growing foreign demand for US coal to supplant weaker domestic demand or reverse the industry's decline."

According to Seaport Global analysts in a report last week, Alliance "shipments, however, won't be flat with 2019 next year; we project they will be much lower."

According to Pipes, Key and Day, "we believe that additional production curtailments are necessary, particularly in the ILB region."

Additionally, in terms of adding competition to the market, according to Fitch, "as coal-fired plants retire, demand for thermal coal will decline, increasing competition among domestic miners."

"Big Food" is training farmers to use regenerative agriculture methods.

General Mills, the packaged food giant, is one of several Big Food corporations jumping on the regenerative agriculture bandwagon, escalating the buzz around the idea that capturing carbon in the soil could reverse climate change. The company took the lead when it announced this spring that it would apply regenerative agriculture to 1 million acres by 2030 — about a quarter of the land from which it sources ingredients in North America.

General Mills has since rolled out a pilot project for oat farmers, as well an open-source self-assessment app available to anyone interested in implementing regenerative practices. Soil health academies and individualized coaching for farmers are in the works, as is the conversion of thousands of conventional acres into organic production.

"We've been looking at these farmers as the examples of what is possible in terms of soil health, diversity and farmer resilience," Mary Jane Melendez, General Mills' chief sustainability and social impact officer, said. "Imagine what you could get if ... more farmers were implementing these practices. It could be revolutionary."

Danone, Kellogg, Nestlé, and a dozen other companies are not far behind. At the recent United Nations Climate Action Summit in New York City, they announced the One Planet Business for Biodiversity (OP2B) coalition to advance regenerative agriculture, rebuild biodiversity and eliminate deforestation. And Land O'Lakes, the dairy and animal feed behemoth, is also touting its soil conservation efforts, including a new initiative to help bolster sustainability on 1.5 million acres of U.S.-grown corn.

David Montgomery, a geologist at the University of Washington and author of “Dirt: The Erosion of Civilizations” and “Growing a Revolution: Bringing Our Soil Back to Life,” said there’s no question that regenerative agriculture can sequester carbon, but the amount of carbon that can be added to the soil is finite. Therefore, it’s not a panacea.

One much-cited estimate of potential soil sequestration published to date suggests that if regenerative practices were used on all of the world’s croplands and pastures forever — a huge assumption — the soil may be able to sequester up to 322 billion tons of carbon dioxide from the atmosphere. That’s a far cry from the 1 trillion ton sequestration some claim possible.

“The claims that you can reverse climate change with regenerative agriculture, that’s a real stretch. The more credible estimates are a good down payment on reducing atmospheric carbon dioxide,” Montgomery said. But he also stresses that the effort can easily be undone.

Policy and solutions / Re: Alaska Coal and Warming
« on: October 29, 2019, 06:17:02 PM »
On peak coal:

EnvironmentAugust 22, 2019 / 9:02 PM / 2 months ago
China's coal demand to peak around 2025, global usage to follow: report

BEIJING (Reuters) - China’s coal demand will start to fall in 2025 once consumption at utilities and other industrial sectors reaches its peak, a state-owned think tank said in a new report, easing pressure on Beijing to impose tougher curbs on fossil fuels.

“With coal demand in China falling gradually, world coal consumption is forecast to reach a peak within 10 years. Meanwhile, China’s coal demand, currently accounting for half of the world’s total, will decline to around 35% by 2050,” the report said.

On coal exporters facing financial difficulties:

Australia’s hopes to expand coal exports in south-east Asia ‘delusional’, experts say

Region’s expected increase in coal-fired power plants could turn out to be ‘more fizz than boom’ as construction rates fall markedly

The number of new coal-fired power plants starting construction across south-east Asia has fallen markedly over the past two years as Australia has increasingly looked to the region to expand its thermal coal exports.

Analysis by US-based climate research and advocacy group Global Energy Monitor found work on only 1.5 gigawatts of new coal generation – equivalent to one large Australian plant – began in the region in the six months to June, all of it in Indonesia.

It follows construction starting on plants with a capacity of 2.7 gigawatts last year, a 57% fall below 2017 levels and 79% less than in 2016.

The government’s chief economist reported in September that south-east Asia was expected to be a key source of growth for thermal coal exports as demand from the biggest markets in Japan, China and Korea declined in coming years. The region increased imports by 15% in 2018 and was the only area in which coal’s share of electricity generation rose.

But Ted Nace, Global Energy Monitor’s executive director, said the latest data suggested the expected south-east Asian thermal coal expansion could turn out to be “more fizz than boom”.
He said as the impetus to combat the climate crisis grew, it was increasingly difficult to get people to commit the hundreds of millions needed to build a coal generator.

Tim Buckley, from thinktank the Institute for Energy Economics and Financial Analysis, said the number of Asian coal projects to have secured financial backing had fallen by between 50% and 70% over the past three years, while the rate of plant closures had increased 50%.

He said it suggested Australia’s thermal coal sales would steadily decline over two-to-three decades. “Any suggestion that thermal coal exports have growth potential is delusional or outright misleading,” he said.

Policy and solutions / Re: Alaska Coal and Warming
« on: October 29, 2019, 06:08:28 PM »
Given that existing coal exporters are struggling financially due to the decrease in the growth of coal demand (it's already declining in the developed economies and coal is projected to peak in the early 2020s), and the amount of investment needed to mine and ship the coal, the project is dead before it even begins.

Note that the economically recoverable reserves in Alaska are barely visible.  There's more than enough economically recoverable coal elsewhere to keep the power plants running for the decade or so that they have left.

Renewables are already cheaper than operating coal in most of the world.  And the price of renewables is continuing to fall.

Policy and solutions / Re: Coal
« on: October 29, 2019, 05:35:12 PM »
Germany slowed the reduction in the use of coal power to phase out nuclear more quickly after Fukushima.  As more renewable capacity is installed, they'll take more coal offline.

Even with the slow-down in retiring coal power plants, the amount of power generated by coal is still decreasing:

From DeConto and Pollard 2018:

4.3 Antarctica
We now use the coupled model to examine the role of mélange during rapid retreat of Antarctic ice. Starting from the ice-sheet model state equilibrated to modern climate (with no mélange), an instantaneous change to a warm ~3 Ma mid Pliocene climate is imposed. As described in Pollard et al. (2015), atmospheric forcing is provided by a regional climate model with a warm austral-summer orbit and atmospheric CO2 level of 400 ppm, and circum-Antarctic ocean temperatures are assumed to warm 2 oC above modern climatology.

Note the bolded assumption.  Ocean temperatures around Antarctica need to be 2 degrees C warmer than they are currently (not warmer than pre-industrial) for MICI to begin.  So how fast are the waters around Antarctica currently warming?

outhern Ocean Warming
Jean-Baptiste Sallée 
Published Online: August 15, 2018

Article Abstract
The Southern Ocean plays a fundamental role in global climate. With no continental barriers, it distributes climate signals among the Pacific, Atlantic, and Indian Oceans through its fast-flowing, energetic, and deep-reaching dominant current, the Antarctic Circumpolar Current. The unusual dynamics of this current, in conjunction with energetic atmospheric and ice conditions, make the Southern Ocean a key region for connecting the surface ocean with the world ocean’s deep seas. Recent examinations of global ocean temperature show that the Southern Ocean plays a major role in global ocean heat uptake and storage. Since 2006, an estimated 60%–90% of global ocean heat content change associated with global warming is based in the Southern Ocean. But the warming of its water masses is inhomogeneous. While the upper 1,000 m of the Southern Ocean within and north of the Antarctic Circumpolar Current are warming rapidly, at a rate of 0.1°–0.2°C per decade, the surface sub­polar seas south of this region are not warming or are slightly cooling. However, subpolar abyssal waters are warming at a substantial rate of ~0.05°C per decade due to the formation of bottom waters on the Antarctic continental shelves. Although the processes at play in this warming and their regional distribution are beginning to become clear, the specific mechanisms associated with wind change, eddy activity, and ocean-ice interaction remain areas of active research, and substantial challenges persist to representing them accurately in climate models.

At current observed rates of warming (with GMSTA around 1C above pre-industrial), the oceans around Antarctica are warming at 0.05 degrees C per decade.  At that rate, it would take 400 years to hit one of the necessary triggers for MICI to start.

That may be why DeConto and Pollard are urging more caution now about the MICI models.  They are still claiming that hydrofracturing could begin as GMSTA approaches 2C above pre-industrial, but that results in centimeters of sea level rise, not meters as MICI would project.

Climatic Thresholds for Widespread Ice Shelf Hydrofracturing and Ice Cliff Calving In Antarctica: Implications for Future Sea Level Rise

Monday, 10 December 2018

Here we explore the implications of hydrofacturing and subsequent ice-cliff collapse in a warming climate, by parameterizing these processes in a hybrid ice sheet-shelf model. Model sensitivities to meltwater production and to ice-cliff calving rate (a function of cliff height above the stress balance threshold triggering brittle failure) are calibrated to match modern observations of calving and thinning. We find the potential for major ice-sheet retreat if global mean temperature rises more than ~2ºC above preindustrial. In the model, Antarctic calving rates at thick ice fronts are not allowed to exceed those observed in Greenland today. This may be a conservative assumption, considering the very different spatial scales of Antarctic outlets, such as Thwaites. Nonetheless, simulations following a ‘worst case’ RCP8.5 scenario produce rates of sea-level rise measured in cm per year by the end of this century. Clearly, the potential for brittle processes to deliver ice to the ocean, in addition to viscous and basal processes, needs to be better constrained through more complete, physically based representations of calving.

Robert M Deconto
University of Massachusetts Amherst
David Pollard
Pennsylvania State University
Knut A Christianson
University of Washington
Richard B Alley
Pennsylvania State University

I'd also note that given trends in the decline of the coal industry and the rate of renewable energy installations in the past two years (the period in which renewables became cheaper than coal and are threatening to overtake natural gas), it's virtually impossible for us to burn enough fossil fuels to hit the RCP8.5 scenario.

Policy and solutions / Re: Coal
« on: October 29, 2019, 12:11:56 AM »
Southeast Asia is supposed to be the region where coal growth is the strongest.  If that's the case, then stick a fork in it, 'cause it's done.

More fizz than boom: 2019 sees coal plant growth in Southeast Asia dwindling as pipeline continues to shrink
Wednesday 23 October, 2019: Despite Southeast Asia being heralded as a major growth region for the coal industry, new data from Global Energy Monitor (GEM) reveals that only Indonesia saw new coal-fired power enter into construction in the first six months of 2019.

According to GEM, this year is shaping to be the second in a row in which the regional coal pipeline has declined sharply, with 1,500 megawatts (MW) entering construction in the first six months of 2019, following only 2,744 MW entering construction during 2018. As shown in Figure 1, construction starts have fallen dramatically since peaking at 12,920 MW in 2016.

According to Ted Nace, Executive Director of GEM, construction starts are a strong indicator of the vitality of the coal pipeline. “New construction is the acid test of whether a proposed project is real or just some plans on paper,” Nace said. “To go into construction you have to get someone to commit hundreds of millions of dollars. In Southeast Asia, it looks like it’s becoming a difficult case to convince people to commit that kind of money.”

Beyond construction, the amount of coal plant capacity in pre-construction stages in Southeast Asia also continues to contract, shrinking 52% from 110,367 MW in mid-2015 to 53,510 MW in mid-2019 (Table 2). With so few projects moving from pre-construction to construction, a continuation of recent trends will mean that most of the remaining 53,510 MW in pre-construction development is more likely to be cancelled rather than implemented.

Permafrost / Re: Permafrost general science thread
« on: October 28, 2019, 11:30:46 PM »

By 2200, the PCF strength in terms of cumulative permafrost carbon flux to the atmosphere is 190 ± 64 Gt C. This estimate may be low because it does not account for amplified surface warming due to the PCF itself and excludes some discontinuous permafrost regions where SiBCASA did not simulate permafrost. We predict that the PCF will change the arctic from a carbon sink to a source after the mid‐2020s and is strong enough to cancel 42–88% of the total global land sink. The thaw and decay of permafrost carbon is irreversible and accounting for the PCF will require larger reductions in fossil fuel emissions to reach a target atmospheric CO2 concentration.

Hattip Jay.
Bolding mine.

This flip should be prevented and thus our collective time frame for action is wrong.

That study came out in 2011 and was considered in the IPCC 2019 SROCC.

The permafrost soil carbon pool is climate sensitive and an order of magnitude larger than carbon stored in plant biomass (Schuur et al., 2018b) (very high confidence). Initial estimates were converging on a range of cumulative emissions from soils to the atmosphere by 2100, but recent studies have actually widened that range somewhat (Figure 3.11) (medium confidence). Expert assessment and laboratory soil incubation studies suggest that substantial quantities of C (tens to hundreds Pg C) could potentially be transferred from the permafrost carbon pool into the atmosphere under RCP8.5 (Schuur et al., 2013; Schädel et al., 2014). Global dynamical models supported these findings, showing potential carbon release from the permafrost zone ranging from 37 to 174 Pg C by 2100 under high emission climate warming trajectories, with an average across models of 92 ± 17 Pg C (mean ± SE) (Zhuang et al., 2006; Koven et al., 2011; Schaefer et al., 2011; MacDougall et al., 2012; Burke et al., 2013; Schaphoff et al., 2013; Schneider von Deimling et al., 2015). This range is generally consistent with several newer data-driven modelling approaches that estimated that soil carbon releases by 2100 (for RCP8.5) will be 57 Pg C (Koven et al., 2015) and 87 Pg C (Schneider von Deimling et al., 2015), as well as an updated estimate of 102 Pg C from one of the previous models (MacDougall and Knutti, 2016). However, the latest model runs performed with either structural enhancements to better represent permafrost carbon dynamics (Burke et al., 2017a), or common environmental input data (McGuire et al., 2016) show similar soil carbon losses, but also indicate the potential for stimulated plant growth (nutrients, temperature/growing season length, CO2 fertilization) to offset some (Kleinen and Brovkin, 2018) or all of these losses, at least during this century, by sequestering new carbon into plant biomass and increasing carbon inputs into the surface soil (McGuire et al., 2018). These future carbon emission levels would be a significant fraction of those projected from fossil fuels with implications for allowable carbon budgets that are consistent with limiting global warming, but will also depend on how vegetation responds (high confidence). Furthermore, there is high confidence that climate scenarios that involve mitigation (e.g. RCP4.5) will help to dampen the response of carbon emissions from the Arctic and boreal regions.

1. How to trigger a shutdown of the MOC? The main engine of the MOC is the downwelling in the polar regions. The critical issue here seems to be the ongoing loss of Arctic sea ice and whether it will be enought to stop the MOC in a <100 years timeframe. (Not much will happen in the Antarctic in this time frame that might affect MOC.)

I disagree with many of your assumptions but the one that I highlight in bold underline above is the most important.  You are posting in the Ice Apocalypse thread and the vast majority of posts in this thread provide supporting evidence that at least significant portions of the WAIS may collapse prior to 2100, possibly due to MICI-mechanisms.  If you care to respond to all of that evidence then I might take your highlighted assumption more seriously, but until then I believe that you are merely repeating consensus science assumptions/caveats on this matter (all of which err on the side of least drama).

Please keep in mind that not even the authors of the MICI hypothesis believe it will occur before the end of this century.

Policy and solutions / Re: Coal
« on: October 18, 2019, 10:18:50 PM »
India requires at least three bidders for any new coal mine projects.  The problem is that the prospects for coal are so dire, that they can't get three bidders on most of their projects.

Tepid response for the coal mine auction rounds
Twesh Mishra New Delhi | Updated on October 10, 2019 Published on October 10, 2019

Just 6 out of 27 mines get adequate bidders

Poor market sentiment and expectations of commercial mining have led to a tepid response for the blocks on offer during the current round of coal auctions.

Policy and solutions / Re: Oil and Gas Issues
« on: October 18, 2019, 07:47:36 PM »
The grim news for US shale drillers continues.

U.S. oil production growth has slammed on the breaks, as low prices and the loss of access to capital markets has forced a slowdown in drilling.

Third quarter earnings reports will soon start to trickle in. Three months ago, the shale industry saw improvement in some of the headline cash flow figures, but the second quarter results also revealed some deeper concerns about drilling operations and raised questions about the longevity of an unprofitable oil boom.

The problem for the shale industry is that, if anything, the outlook has only become gloomier since. Oil prices have languished and investors have grown more skeptical.

The cutbacks have translated into slower output and have led to questions about the “end” of the shale boom.

“A marked slowdown in the US shale patch since the start of the year has led us to lower our expectations slightly for US crude production for 2019 and 2020,” the International Energy Agency (IEA) said in its October Oil Market Report. “Despite many new pipeline projects coming on-line during 2H19, operators continue to lay off rigs and instead prioritise investor returns.”

The Paris-based energy agency noted that U.S. oil production only grew by 140,000 between January and July, a notably modest increase, especially when compared to the 740,000 bpd U.S. drillers added in the same period last year.

The IEA said that cutbacks in spending were a big part of the slowdown. “Pure-play shale producers and independents had already flagged a 6% decline in upstream spending this year in their initial 2019 guidance,” the agency said. “Operators shed another 29 rigs during September so that by end-month, there were 172 fewer active rigs than at end-2018. The frac spread count has declined 23% since March, to a 2.5-year low.”

Policy and solutions / Re: Renewable Energy
« on: October 18, 2019, 07:43:24 PM »
Here's a link to an interesting article about how renewables are being built to replace a coal power plant powering a large still mill in Colorado.

As I watched recently, the great arc furnace at one of the nation’s most storied steel mills was sucking in more electrical power than any other machine in Colorado, produced in part at a plant a few miles away that burns Wyoming coal by the ton.

But the electrical supply for the mill is changing.

A huge solar farm, one of the largest in the country, is to be built here on the grounds of the Evraz Rocky Mountain Steel mill. In addition to producing power for the giant mill, the farm, Bighorn Solar, will supply homes and businesses across Colorado. So far as I can tell, Evraz Rocky Mountain will be the first steel mill in the world that can claim to be powered largely by solar energy.

There is a caveat: The mill operates 24 hours a day and solar panels do not, of course. Over the course of a year the solar farm is expected to produce electricity roughly equal to 95 percent of the mill’s annual demand. On sunny days, excess power will be sold to the Colorado grid, but at night the mill will draw power from the grid, which still includes a good bit of fossil energy.

But that is getting fixed, too. Xcel Energy, the utility that supplies the Pueblo mill with electricity, has made one of the most ambitious commitments in the country to clean up its system. Luckily, about the time solar panels are going dark, strong winds whip up across the plains of eastern Colorado, where wind turbines will turn it into power.

Alice Jackson, who runs the Colorado division of Xcel, told me that at certain hours during the night, wind farms can supply as much as 70 percent of the power on the state grid, and that is likely to be true more and more often as the company signs contracts with new wind farms.

Why would a steel mill install a solar power plant next door? The company cares about going green, certainly, but this is also about money.

We do not know the exact price the company will pay for its solar power — that is a secret under Colorado law — but we do know that the cost of large-scale solar farms has plummeted. To improve its finances, Evraz seems to be locking in low-cost power for the long term.

Policy and solutions / Re: Renewable Energy
« on: October 15, 2019, 11:56:00 PM »

From 2016 through 2019, Argentina’s government awarded contracts for 6.5 gigawatts (GW) of new renewable energy capacity, helping make wind and solar the country’s cheapest unsubsidized sources of energy. Roughly 5 GW of this capacity is already either in operation or under construction, attracting nearly $7.5 billion in new investment and creating more than 11,000 new jobs.

How is it "unsubsidized" when the government is footing the bill?

Isn't it socialism when Government owns the means of production?  Does that mean that all socialist enterprises are subsidized?

Do you think there might be a scenario between "nothing to see here" and "we're already doomed and there's nothing we can do about it?" 

The "consensus scientists" that many posters here sneer about seem to be operating as if there is a possibility that if we cut our carbon emissions, we may end up in a far more livable future than if we don't.  Based on what I've read, I tend to believe the scientists.

Policy and solutions / Re: Oil and Gas Issues
« on: October 15, 2019, 08:59:00 PM »
A couple of related articles from unrelated sources.

First, the problem for the fossil fuel companies:

Opinion: The energy revolution is already here

Published: Oct 14, 2019 6:10 p.m. ET
The transition to low-carbon fuels is occurring faster than most people think
By Jules Kortenhorst

BOULDER, Colorado (Project Syndicate) — For the longest time, the prevailing narrative about renewable energy featured clumsy technologies, high costs, and burdensome subsidies. In the absence of strict mandates and far-reaching policy changes, the chances for mass adoption seemed slim. Electric vehicles (EVs) simply couldn’t go the distance, and LED lights were unattractive and unaffordable.

But now that these technologies have come of age, a new story is being written. Around the world, businesses, governments, and households are taking advantage of more cost-effective low-carbon technologies.

As in any rapid transition, a full understanding of what is happening has lagged behind events. Many incumbent energy producers find it hard to believe that their world is undergoing a revolutionary change, so they insist that their heavily polluting technologies will remain relevant and necessary for some time to come.

And the inevitable consequences of renewables being cheaper than fossil fuels:

Rise of renewables may see off oil firms decades earlier than they think
Pace of progress raises hope that fossil fuel companies could lose their domination

The world’s rising reliance on fossil fuels may come to an end decades earlier than the most polluting companies predict, offering early signs of hope in the global battle to tackle the climate crisis.

The climate green shoots have emerged amid a renewable energy revolution that promises an end to the rising demand for oil and coal in the 2020s, before the fossil fuels face a terminal decline.

The looming fossil fuel peak is expected to emerge decades ahead of forecasts from oil and mining companies, which are betting that demand for polluting energy will rise until the 2040s.

Policy and solutions / Re: Renewable Energy
« on: October 15, 2019, 08:50:12 PM »
Vietnam isn't the only country that has gone from negligible to significant renewable electricity generation in a short time.  Argentina started a program in 2016 that is now greatly increasing the share of electricity generated from renewables.

Oct 15, 2019, 07:20am
Argentina May Be the Hottest Renewable Energy Market You Haven’t Heard Of. Can It Spur a Global Boom?

Silvio Marcacci

An innovative approach unlocked Argentina’s renewable energy market, making it “the most interesting in the world” in just three years. And now, the approach could open the door to billions in renewable investment in developing nations worldwide.

From 2016 through 2019, Argentina’s government awarded contracts for 6.5 gigawatts (GW) of new renewable energy capacity, helping make wind and solar the country’s cheapest unsubsidized sources of energy. Roughly 5 GW of this capacity is already either in operation or under construction, attracting nearly $7.5 billion in new investment and creating more than 11,000 new jobs.

When fully operational, these projects will push renewables to 18% of Argentina’s total power supply – a breakthrough considering they were at just 1.8% before 2016 – and could avoid more than 2 gigatons of carbon dioxide (CO2) emissions over the next 20 years. 

Argentina’s renewable energy boom created wide-ranging economic and climate benefits. According to the Secretariat of Energy, renewable energy project prices fell by a factor of five from around $240/MWh in 2015 to $50-$60/MWh in 2016-2019, making wind and solar the country’s cheapest unsubsidized sources of energy. Nine new manufacturing plants were built in the country, creating 11,000 new project development and equipment manufacturing jobs.

Now, Argentina’s success could go global with the assistance of a Climate Breakthrough Project award to Undersecretary Kind, who is adapting the RenovAr model to other emerging economies through the Global Renewable Energy Mass Adoption Program (GREENMAP).

GREENMAP intends to create renewable energy markets in countries with underdeveloped renewable energy resources and longstanding financial barriers arising from political or economic instability. By setting up standardized tool kits and credit enhancement instruments, model contracts, established eligibility criteria, and international funding guarantees, GREENMAP aims to attract renewable energy investment and reduce project prices.

The upside could be massive, says Undersecretary Kind: 75 GW of new renewable energy capacity, $110 billion in new greenfield investment, and 3 gigatons avoided CO2 emissions within the next 20 years. GREENMAP is targeting at least 15 countries where dependence on fossil fuel imports has reduced energy access, increased energy prices, and pushed up greenhouse gas emissions, while worsening economic and environmental conditions.

Policy and solutions / Re: Global economics and finances - impacts
« on: October 15, 2019, 07:42:34 PM »
The investors of the $13.4 billion University of California endowment and $70 billion pension fund are divesting from fossil fuels.  The reasons aren't political pressure but that the investments are too risky.

We are investors and fiduciaries for what is widely considered the best public research university in the world. That makes us fiscally conservative by nature and by policy — “Risk rules” is one of the 10 pillars of what we call the UC Investments Way. We want to ensure that the more than 320,000 people currently receiving a UC pension actually get paid, that we can continue to fund research and scholarships throughout the UC system, and that our campuses and medical centers earn the best possible return on their investments.

We believe hanging on to fossil fuel assets is a financial risk. That’s why we will have made our $13.4-billion endowment “fossil free” as of the end of this month, and why our $70-billion pension will soon be that way as well.

So what’s the bottom line?

In April 2014, when Jagdeep arrived to become UC’s chief investment officer, UC Investments had a total of $91.6 billion in assets under management. As of June 30, the total portfolio stood at $126.1 billion. In five years, that includes $2.4 billion in value added above our benchmarksand a savings of $1 billion in reduced costs of management.

During that same time frame, we made no new investments in fossil fuels and four years ago, we sold our exposure to coal and oil sands. We found them too risky — and it’s worth noting that Jagdeep joined UC from one of Canada’ sovereign wealth funds in the heart of the oil sands region. We continue to believe there are more attractive investment opportunities in new energy sources than in old fossil fuels.

Policy and solutions / Re: Renewable Energy
« on: October 15, 2019, 07:35:16 PM »
State and local requirements as well as corporate PPAs are driving large increases in projections for growth of solar in the US Midwest in the next decade.

The Midwest’s solar future will be unlike anything seen before
Fitch Solutions Marco Research has boldly predicted the region will be a main driver towards the 100 GW of solar power capacity expected to hit the U.S. over the next 10 years. The procurement [sic] will be led by city and utility commitments to renewable energy, the falling costs of solar and the continued expansion of popular community solar programs.

October 11, 2019 Tim Sylvia

Chief among those bold predictions, Fitch states that it expects the region to contribute heavily to the 100 GW of solar power capacity expected to come to the United States over the next 10 years. This astronomical, gargantuan, whichever word of scope you use to describe, prediction is supported mainly by the region’s large proposed solar project pipeline, with a total potential added capacity of a smidge under 79 GWac that are registered within the MISO, SPP and PJM generation interconnection queues – the grid operators that cover the region.

Fitch expects that this unprecedented development will be driven by the strengthened renewable energy targets of Midwest states, cities and utilities. Chiefly among these targets, Fitch references Wisconsin’s 100% carbon-free electricity by 2050 goal, the 100% renewable electricity pledges made by Chicago, IL and Madison, WI, DTE and Xcel’s plans for carbon neutrality by 2050 and the litany of renewable energy-based requests for proposals sweeping the region.

Strangely, the report doesn’t address the trend of large corporations increasingly adopting renewable generations to fulfill their power needs. The report, however, also attributes the projected growth to year-ver [sic]-year improvements in the technologies associated with solar projects, the evert [sic]-falling costs of developing and installing solar and the expanding adoption of community solar initiatives in the region.

Permafrost / Re: Arctic Methane Release
« on: October 15, 2019, 07:25:10 PM »
Any links to research relating to non russian (or non S&S) methane research cruises there?

And links to the work of ´multiple scientists look at the ESAS using both similar and more complex methods and have come back with radically different answers.´?

It would be interesting to contrast those just to see what kind of emissions we can expect as a lower bound.

Outside of replication we have things like the #1087 record size plumes. Something you could have expected in this starkly warming world.

I wonder if the more complex methods reproduce them...

Here's a link to the Thornton et. al 2016 paper about their 2014 cruise in the same area that S&S covered.

The Laptev and East Siberian Seas have been proposed as a substantial source of methane (CH4) to the atmosphere. During summer 2014, we made unique high‐resolution simultaneous measurements of CH4 in the atmosphere above, and surface waters of, the Laptev and East Siberian Seas. Turbulence‐driven sea‐air fluxes along the ship's track were derived from these observations; an average diffusive flux of 2.99 mg m−2 d−1 was calculated for the Laptev Sea and for the ice‐free portions of the western East Siberian Sea, 3.80 mg m−2 d−1. Although seafloor bubble plumes were observed at two locations in the study area, our calculations suggest that regionally, turbulence‐driven diffusive flux alone accounts for the observed atmospheric CH4 enhancements, with only a local, limited role for bubble fluxes, in contrast to earlier reports. CH4 in subice seawater in certain areas suggests that a short‐lived flux also occurs annually at ice‐out.

Also, if there were persistent methane leaks in the amount of those hyped by S&S recently, the methane would drift to the observation sites around the Arctic.  There's a paper that looked for increased methane concentrations due to those types of emissions from the ESAS that was published in 2016.

Atmospheric constraints on the methane emissions from the East Siberian Shelf

Abstract. Subsea permafrost and hydrates in the East Siberian Arctic Shelf (ESAS) constitute a substantial carbon pool, and a potentially large source of methane to the atmosphere. Previous studies based on interpolated oceanographic campaigns estimated atmospheric emissions from this area at 8–17TgCH4 yr−1. Here, we propose insights based on atmospheric observations to evaluate these estimates. The comparison of high-resolution simulations of atmospheric methane mole fractions to continuous methane observations during the whole year 2012 confirms the high variability and heterogeneity of the methane releases from ESAS. A reference scenario with ESAS emissions of 8TgCH4 yr−1, in the lower part of previously estimated emissions, is found to largely overestimate atmospheric observations in winter, likely related to overestimated methane leakage through sea ice. In contrast, in summer, simulations are more consistent with observations. Based on a comprehensive statistical analysis of the observations and of the simulations, annual methane emissions from ESAS are estimated to range from 0.0 to 4.5TgCH4 yr−1. Isotopic observations suggest a biogenic origin (either terrestrial or marine) of the methane in air masses originating from ESAS during late summer 2008 and 2009.

Note that this paper confirmed the S&S estimates for summer emissions, but found that the winter emissions were far less than those assumed by S&S.

The stories about the recent large plume of methane measured by S&S are mostly hype.  We've seen other stories about methane bubbling up in the past, this is the first time they've been measured while actually active.  There are many pingo-like features on both land in the Arctic (the famous Yamal methane craters are an example) and below the sea.  Here's a paper describing the sub-sea pingo like features.

Methane release from pingo‐like features across the South Kara Sea shelf, an area of thawing offshore permafrost

The Holocene marine transgression starting at ~19 ka flooded the Arctic shelves driving extensive thawing of terrestrial permafrost. It thereby promoted methanogenesis within sediments, the dissociation of gas hydrates, and the release of formerly trapped gas, with the accumulation in pressure of released methane eventually triggering blowouts through weakened zones in the overlying and thinned permafrost. Here we present a range of geophysical and chemical scenarios for the formation of pingo‐like formations (PLFs) leading to potential blowouts. Specifically, we report on methane anomalies from the South Kara Sea shelf focusing on two PLFs imaged from high‐resolution seismic records. A variety of geochemical methods are applied to study concentrations and types of gas, its character, and genesis. PLF 1 demonstrates ubiquitously low‐methane concentrations (14.2–55.3 ppm) that are likely due to partly unfrozen sediments with an ice‐saturated internal core reaching close to the seafloor. In contrast, PLF 2 reveals anomalously high‐methane concentrations of >120,000 ppm where frozen sediments are completely absent. The methane in all recovered samples is of microbial and not of thermogenic origin from deep hydrocarbon sources. However, the relatively low organic matter content (0.52–1.69%) of seafloor sediments restricts extensive in situ methane production. As a consequence, we hypothesize that the high‐methane concentrations at PLF 2 are due to microbial methane production and migration from a deeper source.

David Archer, an expert in global methane sources, debunked hype about the Siberian craters years ago at Real Climate.

Siberia has explosion holes in it that smell like methane, and there are newly found bubbles of methane in the Arctic Ocean. As a result, journalists are contacting me assuming that the Arctic Methane Apocalypse has begun. However, as a climate scientist I remain much more concerned about the fossil fuel industry than I am about Arctic methane. Short answer: It would take about 20,000,000 such eruptions within a few years to generate the standard Arctic Methane Apocalypse that people have been talking about. Here’s where that statement comes from:
How much methane emission is “a lot”? The yardstick here comes from Natalie Shakhova, an Arctic methane oceanographer and modeler at the University of Fairbanks. She proposed that 50 Gton of methane (a gigaton is 1015 grams) might erupt from the Arctic on a short time scale Shakhova (2010). Let’s call this a “Shakhova” event. There would be significant short-term climate disruption from a Shakhova event, with economic consequences explored by Whiteman et al Whiteman et al (2013). The radiative forcing right after the release would be similar to that from fossil fuel CO2 by the end of the century, but subsiding quickly rather than continuing to grow as business-as-usual CO2 does.

If the bubble was pure methane, it would have contained about … wait for it … 0.000003 Gtons of methane. In other words, building a Shakhova event from these explosions would take approximately 20,000,000 explosions, all within a few years, or else the climate impact of the methane would be muted by the lifetime effect.

There have been many studies (by both Russian and non-Russian scientists) into methane emissions from the Arctic seafloor.  Here is an example.

Methane oxidation following submarine permafrost degradation: Measurements from a central Laptev Sea shelf borehole

Submarine permafrost degradation has been invoked as a cause for recent observations of methane emissions from the seabed to the water column and atmosphere of the East Siberian shelf. Sediment drilled 52 m down from the sea ice in Buor Khaya Bay, central Laptev Sea revealed unfrozen sediment overlying ice‐bonded permafrost. Methane concentrations in the overlying unfrozen sediment were low (mean 20 µM) but higher in the underlying ice‐bonded submarine permafrost (mean 380 µM). In contrast, sulfate concentrations were substantially higher in the unfrozen sediment (mean 2.5 mM) than in the underlying submarine permafrost (mean 0.1 mM). Using deduced permafrost degradation rates, we calculate potential mean methane efflux from degrading permafrost of 120 mg m−2 yr−1 at this site. However, a drop of methane concentrations from 190 µM to 19 µM and a concomitant increase of methane δ13C from −63‰ to −35‰ directly above the ice‐bonded permafrost suggest that methane is effectively oxidized within the overlying unfrozen sediment before it reaches the water column. High rates of methane ebullition into the water column observed elsewhere are thus unlikely to have ice‐bonded permafrost as their source.

Here is the article linked to from Skeptical Science (in my post above).

A Terrifying Sea-Level Prediction Now Looks Far Less Likely
But experts warn that our overall picture of sea-level rise looks far scarier today than it did even five years ago.
Robinson Meyer
Jan 4, 2019

One of the scariest scenarios for near-term, disastrous sea-level rise may be off the table for now, according to a new study previewed at a recent scientific conference.

Two years ago, the glaciologists Robert DeConto and David Pollard rocked their field with a paper arguing that several massive glaciers in Antarctica were much more unstable than previously thought. Those key glaciers—which include Thwaites Glacier and Pine Island Glacier, both in the frigid continent’s west—could increase global sea levels by more than three feet by 2100, the paper warned. Such a rise could destroy the homes of more than 150 million people worldwide.

They are now revisiting those results. In new work, conducted with three other prominent glaciologists, DeConto and Pollard have lowered some of their worst-case projections for the 21st century. Antarctica may only contribute about a foot of sea-level rise by 2100, they now say. This finding, reached after the team improved their own ice model, is much closer to projections made by other glaciologists.

Skeptical Science has a good webpage about MICI here.

It covers DeConto and Pollard's 2016 paper, the Edwards et. al 2019 response and discuss updates planned by DeConto and Pollard.

In that 2016 paper, DeConto and his co-author, Prof David Pollard of Penn State University, used an ice sheet model to ascertain how periods in the Earth’s history that were only slightly warmer than today managed to have sea levels that were many metres higher.
Simulating the Pliocene, around three million years ago, and the Last Interglacial, 130,000-115,000 years ago, DeConto and Pollard found that the high sea levels from those periods could only be recreated when MICI was included. DeConto explains:
“One key point is that including these brittle processes in ice sheet models is the best way we’ve found to reproduce the high sea levels we see in the geologic past.”
Turning their attention to the future, DeConto and Pollard ran model simulations calibrated on their findings for the past. They found that including MICI “greatly increases the pace of future sea level rise in high greenhouse gas emissions scenarios”, says DeConto.
The new paper revisits these estimates. It uses a statistical model, called an “emulator”, to replicate the model created by DeConto and Pollard. This allowed the researchers to expand the number of model simulations they ran to explore the full range of possible future outcomes – including those that do not include MICI – as well as calibrating the model with satellite data.
In simulations with MICI, the “most likely” model outcome under the high-emissions RCP8.5 scenario is a contribution from Antarctica of 45cm by 2100, says lead author Dr Tamsin Edwards, a climate scientist and lecturer at King’s College London. She tells Carbon Brief:
“This is much lower than the mean values in DeConto & Pollard – interpreted by many as the most likely values – which ranged from 64cm to 114 cm.”
But their findings also suggest that MICI was not necessary to produce the sea level rise seen in the Pliocene or the Last Interglacial. Without MICI, their most likely contribution from Antarctica is 15cm by 2100 under RCP8.5, with a “likely” range of 13-31cm. There is just a 5% likelihood of Antarctica contributing more than 39cm to sea levels by 2100, Edwards says:

DeConto and Pollard are also currently revisiting their 2016 results in a new paper. DeConto says he is not able to comment on it directly as it is undergoing peer review. However, he has presented some preliminary results at the Fall Meeting of the American Geophysical Union (AGU) in December.
An article published in the Atlantic shortly afterwards reported that DeConto and Pollard “have lowered some of their worst-case projections for the 21st century” after making improvements to their model. The results are likely to put Antarctica’s contribution to sea level rise in 2100 at “about a foot” (30cm), the article says, which is “much closer to projections made by other glaciologists”.

Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: October 11, 2019, 09:26:05 PM »
     FWIW, the September 2019 IPCC cryosphere report shows Extent becoming asymptotic at about 10% of the 2000 level around 2070.
     Given the length and detail of the IPCC cryosphere report, there is a surprisingly brief discussion of Arctic sea ice trends.  ASIF is a better source than IPCC! (seriously). After a quick search, I found nothing in the IPCC report about ASI volume projections.  Figure 3.3 on page 3-13 is the closest information.  It charts ASI Extent under the RCP scenarios.  In those projections, even the RCP8.5 scenario retains 10% September Extent for 2070-2100. 

      The scientists who donate their hard work to IPCC reports are the experts and I feel like an ungrateful flea telling the dog what to do in critiquing their work.  But my small fevered brain is unable to reconcile the trends charted by Wipneus and Stephan, or that I can see for myself in the data from PIOMAS, with the IPCC statements shown below from page 3-25.  To be blunt, I suspect that the IPCC is under-estimating the severity of the ASI trends.

Same conclusions (on bold, made by me), long time ago. The IPCC is in fact, avoiding the discussion of when the Arctic will be ice free. It is easier to simulate that they are doing their work, at the same time that they respect politicians.

On the other hand, some of them are politicians!
 ---> IPCC: Intergovernmental Panel of Climate Change.

Greta Thunberg speech at UN Climate Change COP24 Conference:

We have not come here to beg world leaders to care. You have ignored us in the past and you will ignore us again.
We have run out of excuses and we are running out of time.
We have come here to let you know that change is coming, whether you like it or not. The real power belongs to the people.
"...we are running out of time" but the IPCC is still talking about 2100.
"...The real power belongs to the people." ---> ASIF?  ;)

Each of the IPCC reports issued this decade has made projections of when the Arctic will be ice free.

AR5 (2013) Chapter 11, page 995

Though most of the CMIP5 models project a nearly ice-free Arctic (sea ice extent less than 1 × 106 km2 for at least 5 consecutive years) at the end of summer by 2100 in the RCP8.5 scenario (see Section, some show large changes in the near term as well. Some previous models project an ice-free summer period in the Arctic Ocean by 2040 (Holland et al., 2006), and even as early as the late 2030s using a criterion of 80% sea ice area loss (e.g., Zhang, 2010). By scaling six CMIP3 models to recent observed September sea ice changes, a nearly ice-free Arctic in September is projected to occur by 2037, reaching the first quartile of the distribution for timing of September sea ice loss by 2028 (Wang and Overland, 2009). However, a number of models that have fairly thick Arctic sea ice produce a slower near-term decrease in sea ice extent compared to observations (Stroeve et al., 2007). Based on a linear extrapolation into the future of the recent sea ice volume trend from a hindcast simulation conducted with a regional model of the Arctic sea ice–ocean system (Maslowski et al., 2012) projected that
it would take only until about 2016 to reach a nearly ice-free Arctic Ocean in summer. However, such an approach not only neglects the effect of year-to-year or longer-term variability (Overland and Wang, 2013) but also ignores the negative feedbacks that can occur when the sea ice cover becomes thin (Notz, 2009). Mahlstein and Knutti (2012) estimated the annual mean global surface warming threshold for nearly ice-free Arctic conditions in September to be ~2°C above the present derived from both CMIP3 models and observations.
An analysis of CMIP3 model simulations indicates that for near-term predictions the dominant factor for decreasing sea ice is increased ice melt, and reductions in ice growth play a secondary role (Holland et al., 2010). Arctic sea ice has larger volume loss when there is thicker ice initially across the CMIP3 models, with a projected accumulated mass loss of about 0.5 m by 2020, and roughly 1.0 m by 2050, with considerable model spread (Holland et al., 2010). The CMIP3 models tended to under-estimate the observed rapid decline of summer Arctic sea ice during the satellite era, but these recent trends are more accurately simulated in the CMIP5 models (see Section For CMIP3 models, results indicate that the changes in Arctic sea ice mass budget over the 21st century are related to the late 20th century mean sea ice thickness distribution (Holland et al., 2010), average sea ice thickness (Bitz, 2008; Hodson et al., 2012), fraction of thin ice cover (Boe et al., 2009) and oceanic heat transport to the Arctic (Mahlstein et al., 2011). Acceleration of sea ice drift observed over the last three decades, underestimated in CMIP3 projections (Rampal et al., 2011), and the presence of fossil-fuel and biofuel soot in the Arctic environment (Jacobson, 2010), could also contribute to ice-free late summer conditions over the Arctic in the near term. Details on the transition to an ice-free summer over the Arctic are presented in Chapter 12 (Sections and

Special Report Global Warming of 1.5C (2018) Chapter 3, Page 205

3.3.8 Sea Ice
Summer sea ice in the Arctic has been retreating rapidly in recent decades. During the period 1997 to 2014, for example, the monthly mean sea ice extent during September (summer) decreased on average by 130,000 km² per year (Serreze and Stroeve, 2015). This is about four times as fast as the September sea ice loss during the period 1979 to 1996. Sea ice thickness has also decreased substantially, with an estimated decrease in ice thickness of more than 50% in the central Arctic (Lindsay and Schweiger, 2015). Sea ice coverage and thickness also decrease in CMIP5 simulations of the recent past, and are projected to decrease in the future (Collins et al., 2013). However, the modelled sea ice loss in most CMIP5 models is much smaller than observed losses. Compared to observations, the simulations are less sensitive to both global mean temperature rise (Rosenblum and
Eisenman, 2017) and anthropogenic CO2 emissions (Notz and Stroeve, 2016). This mismatch between the observed and modelled sensitivity of Arctic sea ice implies that the multi-model-mean responses of future sea ice evolution probably underestimates the sea ice loss for a given amount of global warming. To address this issue, studies estimating the future evolution of Arctic sea ice tend to bias correct the model simulations based on the observed evolution of Arctic sea ice in response to global warming. Based on such bias correction, pre-AR5 and post-AR5 studies generally agree that for 1.5°C of global warming relative to pre-industrial levels, the Arctic Ocean will maintain a sea ice cover throughout summer in most years (Collins et al., 2013; Notz and Stroeve, 2016; Screen and Williamson, 2017; Jahn, 2018; Niederdrenk and Notz, 2018; Sigmond et al., 2018). For 2°C of global warming, chances of a sea ice-free Arctic during summer are substantially higher (Screen and Williamson, 2017; Jahn, 2018; Niederdrenk and Notz, 2018; Screen et al., 2018; Sigmond et al., 2018). Model simulations suggest that there will be at least one sea ice-free Arctic5 summer after approximately 10 years of stabilized warming at 2°C, as compared to one sea ice-free summer after 100 years of stabilized warming at 1.5°C above pre-industrial temperatures (Jahn, 2018; Screen et al., 2018; Sigmond et al., 2018). For a specific given year under stabilized warming of 2°C, studies based on large ensembles of simulations with a single model estimate the likelihood of ice-free conditions as 35% without a bias correction of the underlying model (Sanderson et al., 2017; Jahn, 2018); as between 10% and >99% depending on the observational record used to correct the sensitivity of sea ice decline to global warming in the underlying model (Niederdrenk and Notz, 2018); and as 19% based on a procedure to correct for biases in the climatological sea ice coverage in the underlying model (Sigmond et al., 2018). The uncertainty of the first year of the occurrence of an icefree Arctic Ocean arising from internal variability is estimated to be about 20 years (Notz, 2015; Jahn et al., 2016).
The more recent estimates of the warming necessary to produce an icefree Arctic Ocean during summer are lower than the ones given in AR5 (about 2.6°C–3.1°C of global warming relative to pre-industrial levels or 1.6°C–2.1°C relative to present-day conditions), which were similar to the estimate of 3°C of global warming relative to pre-industrial levels (or 2°C relative to present-day conditions) by Mahlstein and Knutti (2012) based on bias-corrected CMIP3 models. Rosenblum and Eisenman (2016) explained why the sensitivity estimated by Mahlstein and Knutti (2012) might be too low, estimating instead that September sea ice in the Arctic would disappear at 2°C of global warming relative to pre-industrial levels (or about 1°C relative to present-day conditions), in line with the other recent estimates. Notz and Stroeve (2016) used the observed correlation between September sea ice extent and cumulative CO2 emissions to estimate that the Arctic Ocean would become nearly free of sea ice during September with a further 1000 Gt of emissions, which also implies a sea ice loss at about 2°C of global warming. Some of the uncertainty in these numbers stems from the possible impact of aerosols (Gagne et al., 2017) and of volcanic forcing (Rosenblum and Eisenman, 2016). During winter, little Arctic sea ice is projected to be lost for either 1.5°C or 2°C of global warming (Niederdrenk and Notz, 2018).

Special Report on Oceans and Crysphere (2019) Chapter 3, Page 3-25

3.2.2 Projected Changes in Sea Ice and Ocean Sea Ice
The multi-model ensemble of historical simulations from CMIP5 models identify declines in total Arctic sea ice extent and thickness (Sections;; Figure 3.3) which agree with observations (Massonnet et al., 2012; Stroeve et al., 2012a; Stroeve et al., 2014a; Stroeve and Notz, 2015). There is a range in the ability of individual models to simulate observed sea ice thickness spatial patterns and sea ice drift rates (Jahn et al., 2012; Stroeve et al., 2014a; Tandon et al., 2018). Reductions in Arctic sea ice extent scale linearly with both global temperatures and cumulative CO2 emissions in simulations and observations (Notz and Stroeve, 2016), although aerosols influenced historical sea ice trends (Gagné et al., 2017). The uncertainty in sea ice sensitivity (ice extent loss per unit of warming) is quite large (Niederdrenk and Notz, 2018) and the model sensitivity is too low in most CMIP5 models (Rosenblum and Eisenman, 2017). Emerging evidence suggests, however, that internal variability, including links between the Arctic and lower latitude, strongly influences the ability of models to simulate observed reductions in Arctic sea ice extent (Swart et al., 2015b; Ding et al., 2018).
CMIP5 models project continued declines in Arctic sea ice through the end of the century (Figure 3.3) (Notz and Stroeve, 2016) (high confidence). There is a large spread in the timing of when the Arctic may become ice free in the summer, and for how long during the season (Massonnet et al., 2012; Stroeve et al., 2012a; Overland and Wang, 2013) as a result of natural climate variability (Notz, 2015; Swart et al., 2015b; Screen and Deser, 2019), scenario uncertainty (Stroeve et al., 2012a; Liu et al., 2013), and model uncertainties related to sea ice dynamics (Rampal et al., 2011; Tandon et al., 2018) and thermodynamics (Massonnet et al., 2018). Internal climate variability results in an uncertainty of approximately 20 years in the timing of seasonally ice-free conditions (Notz, 2015; Jahn, 2018), but the clear link between summer sea ice extent and cumulative CO2 emissions provide a basis for when consistent ice-free conditions may be expected. For stabilized global warming of 1.5°C, sea ice in September is likely to be present at end of century with an approximately 1% chance of individual ice-free years (Notz and Stroeve, 2016; Sanderson et al., 2017; Jahn, 2018; Sigmond et al., 2018); after 10 years of stabilized warming at a 2°C increase, more frequent occurrence of an ice-free summer Arctic is expected (around 10-35%) (Mahlstein and Knutti, 2012; Jahn et al., 2016; Notz and Stroeve, 2016). Model simulations show that a temporary temperature overshoot of a warming target has no lasting impact on ice cover (Armour et al., 2011; Ridley et al., 2012; Li et al., 2013).

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