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AbruptSLR

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Re: Conservative Scientists & its Consequences
« Reply #2150 on: March 02, 2018, 06:17:48 PM »
The linked reference evaluates 19 previously proposed constraints on ECS, and it could not verify the applicability of 15 of these proposed constraints, but it did find that 4 of the 19 constraints "… all predict relatively high climate sensitivity."

 Peter M. Caldwell, Mark D. Zelinka, and Stephen A. Klein (2018), "Evaluating Emergent Constraints on Equilibrium Climate Sensitivity", Journal of Climate, https://doi.org/10.1175/JCLI-D-17-0631.1

https://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-17-0631.1?utm_content=buffer3197b&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

Abstract: "Emergent constraints are quantities which are observable from current measurements and have skill predicting future climate. This study explores 19 previously-proposed emergent constraints related to equilibrium climate sensitivity (ECS, the global-average equilibrium surface temperature response to CO2 doubling). Several constraints are shown to be closely related, emphasizing the importance for careful understanding of proposed constraints. A new method is presented for decomposing correlation between an emergent constraint and ECS into terms related to physical processes and geographical regions. Using this decomposition, one can determine whether the processes and regions explaining correlation with ECS correspond to the physical explanation offered for the constraint. Shortwave cloud feedback is generally found to be the dominant contributor to correlations with ECS because it is the largest source of inter-model spread in ECS. In all cases, correlation results from interaction between a variety of terms, reflecting the complex nature of ECS and the fact that feedback terms and forcing are themselves correlated with each other. For 4 of the 19 constraints, the originally-proposed explanation for correlation is borne out by our analysis. These 4 constraints all predict relatively high climate sensitivity. The credibility of 6 other constraints is called into question due to correlation with ECS coming mainly from unexpected sources and/or lack of robustness to changes in ensembles. Another 6 constraints lack a testable explanation and hence cannot be confirmed. The fact that this study casts doubt upon more constraints than it confirms highlights the need for caution when identifying emergent constraints from small ensembles."
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AbruptSLR

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Re: Conservative Scientists & its Consequences
« Reply #2151 on: March 14, 2018, 06:58:48 PM »
More (than previously expected) global warming induced avalanches could accelerate ice mass loss from mountain glaciers and snow caps:

Title: "Global warming found to be causing an increase in snow avalanches in Western Himalayas"

https://phys.org/news/2018-03-global-avalanches-western-himalayas.html

Extract: "A team of researchers from across Europe has found that rising temperatures due to global warming have been causing more avalanches in the Western Himalayas than in the past. In their paper published in Proceedings of the National Academy of Sciences, the group outlines their study and findings and suggest that their results indicate that new risk management policies need to be put in place. "
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AbruptSLR

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Re: Conservative Scientists & its Consequences
« Reply #2152 on: March 19, 2018, 01:27:06 AM »
It would be nice to think the IPCC projections include this feedback between Arctic ice volume and Asia monsoon food production (but I doubt that they do):

T. Stevens, J.-P. Buylaert, C. Thiel, G. Újvári, S. Yi, A. S. Murray, M. Frechen, H. Lu. Ice-volume-forced erosion of the Chinese Loess Plateau global Quaternary stratotype site. Nature Communications, 2018; 9 (1) DOI: 10.1038/s41467-018-03329-2

http://www.nature.com/articles/s41467-018-03329-2

Abstract: "The International Commission on Stratigraphy (ICS) utilises benchmark chronostratigraphies to divide geologic time. The reliability of these records is fundamental to understand past global change. Here we use the most detailed luminescence dating age model yet published to show that the ICS chronology for the Quaternary terrestrial type section at Jingbian, desert marginal Chinese Loess Plateau, is inaccurate. There are large hiatuses and depositional changes expressed across a dynamic gully landform at the site, which demonstrates rapid environmental shifts at the East Asian desert margin. We propose a new independent age model and reconstruct monsoon climate and desert expansion/contraction for the last ~250 ka. Our record demonstrates the dominant influence of ice volume on desert expansion, dust dynamics and sediment preservation, and further shows that East Asian Summer Monsoon (EASM) variation closely matches that of ice volume, but lags insolation by ~5 ka. These observations show that the EASM at the monsoon margin does not respond directly to precessional forcing."

See also:

Title: "Desertification and monsoon climate change linked to shifts in ice volume and sea level"

https://www.sciencedaily.com/releases/2018/03/180307100841.htm

Extract: "The East Asian summer monsoon and desertification in Eurasia is driven by fluctuating Northern Hemisphere ice volume and global sea level during the Ice Age, as shown in a study published in Nature Communications. Today, two thirds of the world's population is dependent on agriculture sustained by rains of the East Asian summer monsoon, and future climate change in this region can therefore have a major impact on global food production.
...
With today's shrinking ice caps and rising sea levels, this has implications for how the Eurasian continent will once again experience changes in the summer monsoon rainfall and desertification."
« Last Edit: March 19, 2018, 02:48:43 AM by AbruptSLR »
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TerryM

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Re: Conservative Scientists & its Consequences
« Reply #2153 on: March 19, 2018, 03:38:44 AM »
 
Any surviving 5ka after our blue ocean event may find the changing monsoons problematical.  ;)
Terry

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Re: Conservative Scientists & its Consequences
« Reply #2154 on: March 19, 2018, 01:34:48 PM »

Any surviving 5ka after our blue ocean event may find the changing monsoons problematical.  ;)
Terry

Actually, they said it was good news, so to speak: "We can now show that when ice volume decreased and sea level rose, the summer monsoon rainfalls in East Asia intensified and spread further inland, while sandy deserts in China retreated.". ie, more agricultural area

AbruptSLR

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Re: Conservative Scientists & its Consequences
« Reply #2155 on: March 22, 2018, 06:53:25 PM »
The linked reference indicates that anthropogenic carbon dioxide emissions increased by about 1.5% in 2017.  As this is signification lower than the measured increase in atmospheric carbon dioxide, either the value is an underestimate, and/or natural positive feedback mechanisms may be accelerating:

Le Quéré, C., Andrew, R. M., Friedlingstein, P., Sitch, S., Pongratz, J., Manning, A. C., Korsbakken, J. I., Peters, G. P., Canadell, J. G., Jackson, R. B., Boden, T. A., Tans, P. P., Andrews, O. D., Arora, V. K., Bakker, D. C. E., Barbero, L., Becker, M., Betts, R. A., Bopp, L., Chevallier, F., Chini, L. P., Ciais, P., Cosca, C. E., Cross, J., Currie, K., Gasser, T., Harris, I., Hauck, J., Haverd, V., Houghton, R. A., Hunt, C. W., Hurtt, G., Ilyina, T., Jain, A. K., Kato, E., Kautz, M., Keeling, R. F., Klein Goldewijk, K., Körtzinger, A., Landschützer, P., Lefèvre, N., Lenton, A., Lienert, S., Lima, I., Lombardozzi, D., Metzl, N., Millero, F., Monteiro, P. M. S., Munro, D. R., Nabel, J. E. M. S., Nakaoka, S.-I., Nojiri, Y., Padin, X. A., Peregon, A., Pfeil, B., Pierrot, D., Poulter, B., Rehder, G., Reimer, J., Rödenbeck, C., Schwinger, J., Séférian, R., Skjelvan, I., Stocker, B. D., Tian, H., Tilbrook, B., Tubiello, F. N., van der Laan-Luijkx, I. T., van der Werf, G. R., van Heuven, S., Viovy, N., Vuichard, N., Walker, A. P., Watson, A. J., Wiltshire, A. J., Zaehle, S., and Zhu, D.: Global Carbon Budget 2017, Earth Syst. Sci. Data, 10, 405-448, https://doi.org/10.5194/essd-10-405-2018, 2018.

https://www.earth-syst-sci-data.net/10/405/2018/

Abstract. Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere – the global carbon budget – is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and methodology to quantify the five major components of the global carbon budget and their uncertainties. CO2 emissions from fossil fuels and industry (EFF) are based on energy statistics and cement production data, respectively, while emissions from land-use change (ELUC), mainly deforestation, are based on land-cover change data and bookkeeping models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) and terrestrial CO2 sink (SLAND) are estimated with global process models constrained by observations. The resulting carbon budget imbalance (BIM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as ±1σ. For the last decade available (2007–2016), EFF was 9.4 ± 0.5 GtC yr−1, ELUC 1.3 ± 0.7 GtC yr−1, GATM 4.7 ± 0.1 GtC yr−1, SOCEAN 2.4 ± 0.5 GtC yr−1, and SLAND 3.0 ± 0.8 GtC yr−1, with a budget imbalance BIM of 0.6 GtC yr−1 indicating overestimated emissions and/or underestimated sinks. For year 2016 alone, the growth in EFF was approximately zero and emissions remained at 9.9 ± 0.5 GtC yr−1. Also for 2016, ELUC was 1.3 ± 0.7 GtC yr−1, GATM was 6.1 ± 0.2 GtC yr−1, SOCEAN was 2.6 ± 0.5 GtC yr−1, and SLAND was 2.7 ± 1.0 GtC yr−1, with a small BIM of −0.3 GtC. GATM continued to be higher in 2016 compared to the past decade (2007–2016), reflecting in part the high fossil emissions and the small SLAND consistent with El Niño conditions. The global atmospheric CO2 concentration reached 402.8 ± 0.1 ppm averaged over 2016. For 2017, preliminary data for the first 6–9 months indicate a renewed growth in EFF of +2.0 % (range of 0.8 to 3.0 %) based on national emissions projections for China, USA, and India, and projections of gross domestic product (GDP) corrected for recent changes in the carbon intensity of the economy for the rest of the world. This living data update documents changes in the methods and data sets used in this new global carbon budget compared with previous publications of this data set (Le Quéré et al., 2016, 2015b, a, 2014, 2013). All results presented here can be downloaded from https://doi.org/10.18160/GCP-2017 (GCP, 2017).
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Archimid

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Re: Conservative Scientists & its Consequences
« Reply #2156 on: March 23, 2018, 02:19:14 AM »
Quote
natural positive feedback mechanisms may be accelerating:

I think this one. That's what's supposed to happen as we incubate the permafrost.
I am an energy reservoir seemingly intent on lowering entropy for self preservation.

jai mitchell

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Re: Conservative Scientists & its Consequences
« Reply #2157 on: March 24, 2018, 02:55:26 PM »
This paper shows that current global soil carbon datasets are underestimating the soil carbon pool by up to 40%.  This indicates that future carbon soil emissions under warming scenarios are underestimating their potential contribution to atmospheric carbon dioxide.

article here:  https://eos.org/research-spotlights/major-uncertainty-in-estimates-of-carbon-trapped-in-soil

paper here:  https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2017GB005678

Large Differences in Global and Regional Total Soil Carbon Stock Estimates Based on SoilGrids, HWSD, and NCSCD: Intercomparison and Evaluation Based on Field Data From USA, England, Wales, and France
Marwa Tifafi
Bertrand Guenet
Christine Hatté
First published: 18 December 2017
https://doi.org/10.1002/2017GB005678

Soils are the major component of the terrestrial ecosystem and the largest organic carbon reservoir on Earth. However, they are a nonrenewable natural resource and especially reactive to human disturbance and climate change. Despite its importance, soil carbon dynamics is an important source of uncertainty for future climate predictions and there is a growing need for more precise information to better understand the mechanisms controlling soil carbon dynamics and better constrain Earth system models. The aim of our work is to compare soil organic carbon stocks given by different global and regional databases that already exist. We calculated global and regional soil carbon stocks at 1 m depth given by three existing databases (SoilGrids, the Harmonized World Soil Database, and the Northern Circumpolar Soil Carbon Database). We observed that total stocks predicted by each product differ greatly: it is estimated to be around 3,400 Pg by SoilGrids and is about 2,500 Pg according to Harmonized World Soil Database. This difference is marked in particular for boreal regions where differences can be related to high disparities in soil organic carbon concentration. Differences in other regions are more limited and may be related to differences in bulk density estimates. Finally, evaluation of the three data sets versus ground truth data shows that (i) there is a significant difference in spatial patterns between ground truth data and compared data sets and that (ii) data sets underestimate by more than 40% the soil organic carbon stock compared to field data.


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AbruptSLR

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Re: Conservative Scientists & its Consequences
« Reply #2158 on: March 24, 2018, 04:36:33 PM »
Quote
natural positive feedback mechanisms may be accelerating:

I think this one. That's what's supposed to happen as we incubate the permafrost.

Here is evidence that current climate scientists have erred on the side of least drama in their projections, with regards to the likely amount of methane that will be emitted from wet degraded permafrost this coming century.

Title: "The Arctic’s carbon bomb might be even more potent than we thought"

https://www.washingtonpost.com/news/energy-environment/wp/2018/03/19/the-arctics-carbon-bomb-might-be-even-more-potent-than-we-thought/?utm_term=.6ffde2423f88

Extract: "Research released Monday suggests that methane releases could be considerably more prevalent as Arctic permafrost thaws. The research finds that in waterlogged wetland soils, where oxygen is not prevalent, tiny microorganisms will produce a considerable volume of methane, a gas that doesn’t last in the air much more than a decade but has a warming effect many times that of carbon dioxide over a period of 100 years."

See also:

Knoblauch et al (2018), "Methane production as key to the greenhouse gas budget of thawing permafrost", Nature Climate Change, doi:10.1038/s41558-018-0095-z

http://www.nature.com/articles/s41558-018-0095-z
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AbruptSLR

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Re: Conservative Scientists & its Consequences
« Reply #2159 on: March 24, 2018, 04:45:48 PM »
I believe that most current climate change projections underestimate the sensitivity of biological carbon sinks/sources to disruption due to an increase in climate change induced extreme weather events.  The linked article discuss an example of the consequences of a severe marine heatwave "… triggering the release of as much as nine million tonnes of carbon dioxide …" in Shark Bay, Australia, in the summer of 2010-11.

Title: "'Unprecedented' marine heatwave triggered huge carbon-dioxide release"

https://www.smh.com.au/environment/climate-change/unprecedented-marine-heatwave-triggered-huge-carbon-dioxide-release-20180319-p4z54b.html

Extract: "A severe heatwave off north-western Western Australia hammered the world's largest region of seagrass, triggering the release of as much as nine million tonnes of carbon dioxide, a paper by international researchers has found.

Two months of temperatures 2-4 degrees above average in the summer of 2010-11 resulted in the loss of about 1000 square-kilometres of seagrass in Shark Bay by 2014, or about a fifth of its extent, according to the paper which was published on Tuesday in Nature Climate Change."
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AbruptSLR

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Re: Conservative Scientists & its Consequences
« Reply #2160 on: March 27, 2018, 04:36:06 PM »
While people can/will interpret history differently, it is my belief that when the IPCC first got started (FAR was issued in 1990) climate scientists were faced with more uncertainty, but also with less political pressure to err on the side of least drama, than today.  Thus in the attached October 2017 Hausfather plot of FAR GMSTA projections vs observed data thru 2016, the projections closely match the observations even thru FAR assumed that ECS was about 2.5C because they also assumed that CO2e concentrations would be higher than observed.  Thus FAR's close projected GMSTA match with observations, can be taken to indicate that ECS is somewhat higher than 3C.

Title: "Analysis: How well have climate models projected global warming?"

https://www.carbonbrief.org/analysis-how-well-have-climate-models-projected-global-warming

Extract: "IPCC First Assessment Report, 1990

The IPCC’s First Assessment Report (FAR) in 1990 featured relatively simple energy balance/upwelling diffusion ocean models to estimate changes in global air temperatures. Their featured business-as-usual (BAU) scenario assumed rapid growth of atmospheric CO2, reaching 418ppm CO2 in 2016, compared to 404ppm in observations. The FAR also assumed continued growth of atmospheric halocarbon concentrations much faster than has actually occurred."
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Daniel B.

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Re: Conservative Scientists & its Consequences
« Reply #2161 on: March 29, 2018, 01:32:00 AM »
While people can/will interpret history differently, it is my belief that when the IPCC first got started (FAR was issued in 1990) climate scientists were faced with more uncertainty, but also with less political pressure to err on the side of least drama, than today.  Thus in the attached October 2017 Hausfather plot of FAR GMSTA projections vs observed data thru 2016, the projections closely match the observations even thru FAR assumed that ECS was about 2.5C because they also assumed that CO2e concentrations would be higher than observed.  Thus FAR's close projected GMSTA match with observations, can be taken to indicate that ECS is somewhat higher than 3C.

Title: "Analysis: How well have climate models projected global warming?"

https://www.carbonbrief.org/analysis-how-well-have-climate-models-projected-global-warming

Extract: "IPCC First Assessment Report, 1990

The IPCC’s First Assessment Report (FAR) in 1990 featured relatively simple energy balance/upwelling diffusion ocean models to estimate changes in global air temperatures. Their featured business-as-usual (BAU) scenario assumed rapid growth of atmospheric CO2, reaching 418ppm CO2 in 2016, compared to 404ppm in observations. The FAR also assumed continued growth of atmospheric halocarbon concentrations much faster than has actually occurred."

To claim that the “projections closely matched the observations” is debatable.  Over the 27 year period, the projections matched the observations 8 times, underestimated the observations 3 times, and overestimated the observations 16 times, 3 of which fell outside their uncertainty boundaries.  The only reason that 2016 was within 17% of the projections was the strong El Niño.  It does not say how much they overestimated CO2 increases, but it would have to be substantial based on the graph.

AbruptSLR

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Re: Conservative Scientists & its Consequences
« Reply #2162 on: March 29, 2018, 04:53:27 AM »
To claim that the “projections closely matched the observations” is debatable.

Your entitled to your opinion, but the match looks close to me.
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Daniel B.

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Re: Conservative Scientists & its Consequences
« Reply #2163 on: March 29, 2018, 02:51:28 PM »
To claim that the “projections closely matched the observations” is debatable.

Your entitled to your opinion, but the match looks close to me.

I guess that depends on how close you are willing to accept.  Through 2005, the match was much closer, with the observations averaging only 13% less than the projections.  However, since then, the observations are averaging 23% less than the projections, with every year falling below the projection, and just one year coming within 10% of the projected value.  That is more than random fluctuations.

AbruptSLR

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Re: Conservative Scientists & its Consequences
« Reply #2164 on: March 29, 2018, 04:23:28 PM »
I guess that depends on how close you are willing to accept.

Per the attached re-tweet by Gavin Schmidt of Zeke Hausfather's original tweet on this matter, the both seem to concur with my opinion of what is reasonably close.
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Daniel B.

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Re: Conservative Scientists & its Consequences
« Reply #2165 on: March 29, 2018, 04:48:25 PM »
I guess that depends on how close you are willing to accept.

Per the attached re-tweet by Gavin Schmidt of Zeke Hausfather's original tweet on this matter, the both seem to concur with my opinion of what is reasonably close.

Alright.  I guess that means we can expect 23% less warming than projected.  That is certainly good news.

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Re: Conservative Scientists & its Consequences
« Reply #2166 on: March 29, 2018, 04:58:11 PM »
The only reason that 2016 was within 17% of the projections was the strong El Niño.

Did other short-term forcings (ENSO, PDO/AMO, Solar, volcanic activity) have an influence when the projections overestimated observations?

And were these projections ever meant as a kind of weather report, where you can say Tuesday/2016 was warmer/colder than what the model predicted? Or is there a difference?
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AbruptSLR

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Re: Conservative Scientists & its Consequences
« Reply #2167 on: March 29, 2018, 05:16:28 PM »
Alright.  I guess that means we can expect 23% less warming than projected.  That is certainly good news.

Title: "If wishes were horses, beggars would ride"

https://en.wikipedia.org/wiki/If_wishes_were_horses,_beggars_would_ride

Extract: ""If wishes were horses, beggars would ride" is an English language proverb and nursery rhyme, first recorded about 1628 in a collection of Scottish proverbs, which suggests if wishing could make things happen, then even the most destitute people would have everything they wanted."

Edit: "The reference to horses was first in James Carmichael's Proverbs in Scots printed in 1628, which included the lines: "And if wishes were horses, pure [poor] men wald ride". The first mention of beggars is in John Ray's Collection of English Proverbs in 1670, in the form "If wishes would bide, beggars would ride".
...
The last line was sometimes used to stop children from questioning and get to work: "If if's and and's were pots and pans, there'd surely be dishes to do.""
« Last Edit: March 29, 2018, 06:15:49 PM by AbruptSLR »
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Daniel B.

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Re: Conservative Scientists & its Consequences
« Reply #2168 on: March 29, 2018, 05:45:11 PM »
The only reason that 2016 was within 17% of the projections was the strong El Niño.

Did other short-term forcings (ENSO, PDO/AMO, Solar, volcanic activity) have an influence when the projections overestimated observations?

And were these projections ever meant as a kind of weather report, where you can say Tuesday/2016 was warmer/colder than what the model predicted? Or is there a difference?

Quite possibly.  If these are significant influences on the entire system, then perhaps they should be included in the projections.

No, I think they were a best guess.  Naturally, that guess can be refined and updated based on newer data. 

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Re: Conservative Scientists & its Consequences
« Reply #2169 on: March 29, 2018, 05:57:11 PM »
Quite possibly.  If these are significant influences on the entire system, then perhaps they should be included in the projections.

They are included in the projections, just not in the sense that weather forecast says we have an El Niño on Tuesday, followed by a La Niña on Wednesday.

Short-term forcings are difficult to project, but more importantly, their negative and positive phases cancel each other out. That's okay, because the interest is in the long-term trend, not the short-term oscillations.

Quote
No, I think they were a best guess.  Naturally, that guess can be refined and updated based on newer data.

They are a best guess for the long term, not for Tuesday/2016. So, if you have a period where short-term forcings converge and temperature is low, you don't immediately refine and update based on that data, because when those short-term forcings flip (for instance, ENSO) and temperatures rise faster again, you'd have to refine and update again.

You refine and update based on the increased understanding of underlying physical processes.

edit: This is textbook stuff, that even an idiot like me knows/deduces. I don't know why I'm stepping in.
« Last Edit: March 29, 2018, 06:02:44 PM by Neven »
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Daniel B.

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Re: Conservative Scientists & its Consequences
« Reply #2170 on: March 29, 2018, 06:30:01 PM »
Quite possibly.  If these are significant influences on the entire system, then perhaps they should be included in the projections.

They are included in the projections, just not in the sense that weather forecast says we have an El Niño on Tuesday, followed by a La Niña on Wednesday.

Short-term forcings are difficult to project, but more importantly, their negative and positive phases cancel each other out. That's okay, because the interest is in the long-term trend, not the short-term oscillations.

Quote
No, I think they were a best guess.  Naturally, that guess can be refined and updated based on newer data.

They are a best guess for the long term, not for Tuesday/2016. So, if you have a period where short-term forcings converge and temperature is low, you don't immediately refine and update based on that data, because when those short-term forcings flip (for instance, ENSO) and temperatures rise faster again, you'd have to refine and update again.

You refine and update based on the increased understanding of underlying physical processes.

edit: This is textbook stuff, that even an idiot like me knows/deduces. I don't know why I'm stepping in.

Naturally.  But we are not talking about one day (Tuesday) or one year (2016).  This has occurred over a 12-year period.  It is very difficult to attribute differences over twelve years to short-term forcings.  Even the ENSO flip was not sufficient to bring the projections in line with the observations.  Perhaps they should update based on better understanding of the underlying physical processes, as you suggest.

AbruptSLR

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Re: Conservative Scientists & its Consequences
« Reply #2171 on: March 29, 2018, 06:36:40 PM »
edit: This is textbook stuff, that even an idiot like me knows/deduces. I don't know why I'm stepping in.

Maybe because you have the patience of Job ;)
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Neven

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Re: Conservative Scientists & its Consequences
« Reply #2172 on: March 29, 2018, 06:55:42 PM »
Even the ENSO flip was not sufficient to bring the projections in line with the observations.

Maybe aerosols, volcanic activity, solar stuff, PDO/AMO didn't flip enough? Would that be possible?

And what are the observations? Do they include the Arctic? Do they account for sea surface temperature measurement methods?

And so on...

Quote
Perhaps they should update based on better understanding of the underlying physical processes, as you suggest.

Who says they aren't?
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Re: Conservative Scientists & its Consequences
« Reply #2173 on: March 29, 2018, 06:55:47 PM »
Perhaps they should update based on better understanding of the underlying physical processes, as you suggest.

The increasing frequency of extreme El Nino events with climate change (even if limited to a 1.5C GMSTA), is part of why ECS increases together with global warming.  Thus projections considering fundamental physicals would show an increasing GMSTA with time for reasons including that extreme El Nino events are becoming more frequent (together with other fundamentals like Arctic Amplification, etc):
 
Wang et al. (2017), "Continued increase of extreme El Nino frequency long after 1.5C warming stabilization", Nature Climate Change, doi:10.1038/nclimate3351

http://www.nature.com/articles/nclimate3351
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Re: Conservative Scientists & its Consequences
« Reply #2174 on: April 02, 2018, 05:21:09 PM »
Per the attached image March had the highest monthly average GMSTA of 2018 (even though we are currently in a La Nina event):
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Re: Conservative Scientists & its Consequences
« Reply #2175 on: April 10, 2018, 03:49:53 PM »
The cited study uses field measurements to demonstrate the unexpectedly (per consensus climate science) high sensitivity of Africa's vegetation to release CO₂ into the atmosphere:

Title: "Africa’s vegetation has lost 2.6bn tonnes of CO2 in just seven years"

https://www.carbonbrief.org/africas-vegetation-has-lost-2-6bn-tonnes-of-co2-in-seven-years

Extract: "The rainforests, savannahs and woodlands of sub-Saharan Africa have lost around 2.6bn tonnes of CO2 over the past seven years, a new study finds.
The large-scale loss of stored carbon – which on an annual basis is almost four times the CO2 emissions of Nigeria – was driven by a series of severe droughts across the continent, as well as deforestation, the research suggests."

See also:

http://www.nature.com/articles/s41559-018-0530-6
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Re: Conservative Scientists & its Consequences
« Reply #2176 on: April 10, 2018, 04:17:37 PM »
The feedbacks just keep kicking in!
"A force de chercher de bonnes raisons, on en trouve; on les dit; et après on y tient, non pas tant parce qu'elles sont bonnes que pour ne pas se démentir." Choderlos de Laclos "You struggle to come up with some valid reasons, then cling to them, not because they're good, but just to not back down."

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Re: Conservative Scientists & its Consequences
« Reply #2177 on: April 10, 2018, 05:14:53 PM »
Perhaps they should update based on better understanding of the underlying physical processes, as you suggest.

The increasing frequency of extreme El Nino events with climate change (even if limited to a 1.5C GMSTA), is part of why ECS increases together with global warming.  Thus projections considering fundamental physicals would show an increasing GMSTA with time for reasons including that extreme El Nino events are becoming more frequent (together with other fundamentals like Arctic Amplification, etc):
 
Wang et al. (2017), "Continued increase of extreme El Nino frequency long after 1.5C warming stabilization", Nature Climate Change, doi:10.1038/nclimate3351

http://www.nature.com/articles/nclimate3351

Does not appear to be the trend recently:

http://blogs.discovermagazine.com/imageo/files/2016/02/Screenshot_2_13_16_9_46_AM-1.jpg

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Re: Conservative Scientists & its Consequences
« Reply #2178 on: April 10, 2018, 05:28:45 PM »

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Re: Conservative Scientists & its Consequences
« Reply #2179 on: April 10, 2018, 05:36:40 PM »
What does the group think of this new scenario?

https://www.shell.com/energy-and-innovation/the-energy-future/scenarios/shell-scenario-sky.html

First, such scenarios are not solutions unless they actually get implemented, and this looks like 'long-tailed' scenario to me.

Second, Shell says that this scenario will that 50-years to be implemented, once adopted.  While I believe that we do not have 50-years if we are going to stay 'well below' the 2C target.
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Re: Conservative Scientists & its Consequences
« Reply #2180 on: April 10, 2018, 11:31:14 PM »
Perhaps they should update based on better understanding of the underlying physical processes, as you suggest.

The increasing frequency of extreme El Nino events with climate change (even if limited to a 1.5C GMSTA), is part of why ECS increases together with global warming.  Thus projections considering fundamental physicals would show an increasing GMSTA with time for reasons including that extreme El Nino events are becoming more frequent (together with other fundamentals like Arctic Amplification, etc):
 
Wang et al. (2017), "Continued increase of extreme El Nino frequency long after 1.5C warming stabilization", Nature Climate Change, doi:10.1038/nclimate3351

http://www.nature.com/articles/nclimate3351

Does not appear to be the trend recently:

http://blogs.discovermagazine.com/imageo/files/2016/02/Screenshot_2_13_16_9_46_AM-1.jpg

Looking at this chart, in the past 35 years (1981 to 2016) there have been 3 very strong, 2 strong and 3 moderate El Ninos. In the 31 years between 1950 and 1981 there were zero very strong, 3 strong and 1 moderate El Ninos.

A simpler way of viewing this chart would be to draw a line connecting the peaks of the strongest El Ninos which have occurred from 1950 to the present, the 1st in 57/58 and the most recent in 15/16 and you will discover a steady climb in strength over time.

I respectfully disagree.

I will admit that I have very little understanding of El Ninos and so, when I look at this chart, I wonder if measures below or above zero which to do not qualify as El Nino or La Nina mean anything.
« Last Edit: April 10, 2018, 11:40:45 PM by Shared Humanity »

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Re: Conservative Scientists & its Consequences
« Reply #2181 on: April 11, 2018, 01:34:40 PM »
Perhaps they should update based on better understanding of the underlying physical processes, as you suggest.

The increasing frequency of extreme El Nino events with climate change (even if limited to a 1.5C GMSTA), is part of why ECS increases together with global warming.  Thus projections considering fundamental physicals would show an increasing GMSTA with time for reasons including that extreme El Nino events are becoming more frequent (together with other fundamentals like Arctic Amplification, etc):
 
Wang et al. (2017), "Continued increase of extreme El Nino frequency long after 1.5C warming stabilization", Nature Climate Change, doi:10.1038/nclimate3351

http://www.nature.com/articles/nclimate3351

Does not appear to be the trend recently:

http://blogs.discovermagazine.com/imageo/files/2016/02/Screenshot_2_13_16_9_46_AM-1.jpg

Looking at this chart, in the past 35 years (1981 to 2016) there have been 3 very strong, 2 strong and 3 moderate El Ninos. In the 31 years between 1950 and 1981 there were zero very strong, 3 strong and 1 moderate El Ninos.

A simpler way of viewing this chart would be to draw a line connecting the peaks of the strongest El Ninos which have occurred from 1950 to the present, the 1st in 57/58 and the most recent in 15/16 and you will discover a steady climb in strength over time.

I respectfully disagree.

I will admit that I have very little understanding of El Ninos and so, when I look at this chart, I wonder if measures below or above zero which to do not qualify as El Nino or La Nina mean anything.

I think you are cherry picking the results.  The 2015/16 El Nino was only slightly stronger than the 1972/73, yet if you include one but not the other, it changes your results significantly.  Looking more objectively, the frequency of strong El Nino's starting in 1950 was one every 8 years up until the Super El Nino of 1982.  After that, the frequency increased to one every 5 years, until the Super El Nino of 1997.  Since then, there has been one strong El Nino (1.5 GMSTA, as mentioned in the paper).  If you include the recent moderate El Ninos, the frequency over the past two decades is still only one every 6 years.  Based on the data over the past six decades, past El Nino events lends no support to his claim of increasing future frequency.

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Re: Conservative Scientists & its Consequences
« Reply #2182 on: April 11, 2018, 07:16:53 PM »
since the early 1990s the shift of aerosol emissions  from europe and the U.S. to china has been shown to have contributed significantly to a dominant negative Pacific Decadal Oscillation regime.

Without these changes, the frequency and scale of El Ninos (under a more positive PDO) woudl be much higher.
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Re: Conservative Scientists & its Consequences
« Reply #2183 on: April 20, 2018, 07:50:29 AM »
While I definitely appreciate the efforts of the developers of the SSPs, just because one churns water doesn't mean that one is making headway:

Title: "Explainer: How ‘Shared Socioeconomic Pathways’ explore future climate change"

https://www.carbonbrief.org/explainer-how-shared-socioeconomic-pathways-explore-future-climate-change

Extract: "Over the past few years, an international team of climate scientists, economists and energy systems modellers have built a range of new “pathways” that examine how global society, demographics and economics might change over the next century. They are collectively known as the “Shared Socioeconomic Pathways” (SSPs).

These SSPs are now being used as important inputs for the latest climate models, feeding into the Intergovernmental Panel on Climate Change (IPCC) sixth assessment report due to be published in 2020-21. They are also being used to explore how societal choices will affect greenhouse gas emissions and, therefore, how the climate goals of the Paris Agreement could be met."
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Re: Conservative Scientists & its Consequences
« Reply #2184 on: April 21, 2018, 08:31:17 AM »
Many SSP and RCP scenarios rely heavily on the use of climate-change mitigation efforts, but the linked reference casts doubt on the carbon uptake potential of BECCS:

Andreas Krause et al. (16 April 2018), "Large uncertainty in carbon uptake potential of land‐based climate‐change mitigation efforts" Global Change Biology, https://doi.org/10.1111/gcb.14144

https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14144

Abstract: "Most climate mitigation scenarios involve negative emissions, especially those that aim to limit global temperature increase to 2°C or less. However, the carbon uptake potential in land‐based climate change mitigation efforts is highly uncertain. Here, we address this uncertainty by using two land‐based mitigation scenarios from two land‐use models (IMAGE and MAgPIE) as input to four dynamic global vegetation models (DGVMs; LPJ‐GUESS, ORCHIDEE, JULES, LPJmL). Each of the four combinations of land‐use models and mitigation scenarios aimed for a cumulative carbon uptake of ~130 GtC by the end of the century, achieved either via the cultivation of bioenergy crops combined with carbon capture and storage (BECCS) or avoided deforestation and afforestation (ADAFF). Results suggest large uncertainty in simulated future land demand and carbon uptake rates, depending on the assumptions related to land use and land management in the models. Total cumulative carbon uptake in the DGVMs is highly variable across mitigation scenarios, ranging between 19 and 130 GtC by year 2099. Only one out of the 16 combinations of mitigation scenarios and DGVMs achieves an equivalent or higher carbon uptake than achieved in the land‐use models. The large differences in carbon uptake between the DGVMs and their discrepancy against the carbon uptake in IMAGE and MAgPIE are mainly due to different model assumptions regarding bioenergy crop yields and due to the simulation of soil carbon response to land‐use change. Differences between land‐use models and DGVMs regarding forest biomass and the rate of forest regrowth also have an impact, albeit smaller, on the results. Given the low confidence in simulated carbon uptake for a given land‐based mitigation scenario, and that negative emissions simulated by the DGVMs are typically lower than assumed in scenarios consistent with the 2°C target, relying on negative emissions to mitigate climate change is a highly uncertain strategy."
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Re: Conservative Scientists & its Consequences
« Reply #2185 on: April 26, 2018, 07:14:42 PM »
Glacial ice mass loss from Franz Josef Land has been measured to be accelerating faster than previously believed by consensus climate science:

Whyjay Zheng et al. (15 June 2018), "Accelerating glacier mass loss on Franz Josef Land, Russian Arctic", Remote Sensing of Environment, Volume 211, Pages 357–375, https://doi.org/10.1016/j.rse.2018.04.004

https://www.sciencedirect.com/science/article/pii/S0034425718301494

Abstract: "The glaciers of the Franz Josef Land (FJL) archipelago in the Russian Arctic are subjected to rapidly-warming temperatures but are small contributors to sea level. We analyze ice surface elevation data derived from satellite stereo imagery (WorldView and SPOT), radar altimetry (CryoSat-2), and a digitized 1953 cartographic map to calculate elevation change rates dhdt. Mass loss from FJL doubled between 2011 and 2015 compared to 1953–2011/2015, increasing from a rate of −2.18 ± 0.72 Gt yr−1 to −4.43 ± 0.78 Gt yr−1. This 2011−2015 rate indicates an acceleration in ice loss from that observed in 2003–2009 by multiple studies using ICESat and GRACE. Glacier thinning rates are spatially highly variable. We observe glacier thinning rates of up to 10 m per year, and in general we see a trend of increased thinning from the NE towards the SW. Glacier retreat is widespread and has led to the creation of at least one new island. Historically, ice wastage from FJL is thought to have been relatively small, but accelerating ice loss may be the new normal for this archipelago in a warming Arctic."
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Re: Conservative Scientists & its Consequences
« Reply #2186 on: April 26, 2018, 10:30:58 PM »
The linked 2008 Editor's Note, discusses the 'John Mercer effect' that "… stands for the fact that scientists (in this case glaciologists) are wary of being similarly characterized as alarmists, particularly because of the impact that this may have on future funding."  This is due to what " … Rachel Carson called "the gods of profit and production", and it will likely lead to a "Climate Catastrophe":

https://list.uvm.edu/cgi-bin/wa?A3=ind0802&L=SCIENCE-FOR-THE-PEOPLE&E=0&P=163360&B=--%3D%3D%3D%3D%3D%3D%3D%3D%3D%3D%3D%3D_-1010152671%3D%3D_ma%3D%3D%3D%3D%3D%3D%3D%3D%3D%3D%3D%3D&T=text%2Fhtml;%20charset=us-ascii

Extract: "Twenty years ago climatologist James Hansen of NASA's Goddard Institute of Space Studies, widely considered to be the world's leading authority on global warming, first brought the issue into the public spotlight in testimony before the U.S. Congress. Recently, Hansen published an article entitled "Climate Catastrophe" in the New Scientist (July 28, 2007), http://www.newscientist.com. There he presented evidence suggesting that under "business as usual," in which greenhouse gas emissions continue to increase unchecked, a rise in sea level by several meters during the present century due to the melting of polar ice sheets is a "near certainty."

A sea level rise of this extent (up to five meters or sixteen feet) would mean the loss of land areas on which much of the earth's population lives at present (10 percent of the world's population live less than ten meters above the mid-tide sea level.). Yet, most scientists, even glaciologists, still downplay the full extent of the danger, failing to acknowledge probable nonlinear processes associated with climate change, and are especially reticent when it comes to making public statements in that regard.

Why? Hansen calls this the "John Mercer effect." In the 1970s John Mercer, a glaciologist at Ohio State University's Institute of Polar Studies, drew attention to the West Antarctic Ice Sheet, which is separated from the bulk of Antarctica by a mountain range. Ice shelves floating on its rim put it in a delicate balance so that global warming, Mercer claimed, could within a mere forty years cause it to disintegrate and slide into the sea, raising the sea level by five meters.

Other glaciologists looked into Mercer's model and decided based on the data collected that what he described could indeed happen. But most climatologists and geologists publicly dismissed the idea that an ice sheet as big as Mexico could disintegrate in less than a few centuries (Spencer R. Weart, The Discovery of Global Warming, pp. 79-80). According to Hansen, although it was not obvious at the time whether Mercer or his critics were correct, "researchers who suggested that his paper was alarmist were regarded as more authoritative." Hansen believes that Mercer lost funding opportunities as a result. This discouraged other scientists from speaking out.

The John Mercer Effect then stands for the fact that scientists (in this case glaciologists) are wary of being similarly characterized as alarmists, particularly because of the impact that this may have on future funding. "Scientists downplaying the dangers of climate change [or other threats to the status quo] fare better when it comes to getting funding." Hansen points to his own experience. In 1981, based on the first reliable estimates of average global temperature by NASA, he pointed to the dangers of global warming from fossil fuel use. The result: his research group had some of its funding pulled by the Department of Energy, which specifically criticized aspects of that paper. Hansen argues that such economic/funding constraints have the effect of inhibiting scientific criticisms of the status quo: "I believe there is pressure on scientists to be conservative." To be sure, scientists are trained to be skeptics, but "excessive caution also holds dangers. 'Scientific reticence' can hinder communication with the public about the dangers of global warming. We may rue reticence if it means no action is taken until it is too late to prevent future disasters."

Hansen's description of the John Mercer Effect reflects the way in which a system devoted to what Rachel Carson called "the gods of profit and production" (see the Review of the Month in this issue) constrains scientists (along with everyone else), whenever issues arise that potentially threaten the vested interests-even when it is a question of protecting human life and the planetary environment. In the United States, where so much of the scientific funding comes from the Pentagon and the large corporations, the John Mercer Effect is especially strong in limiting what scientists are willing to say and do. As Richard Levins and Richard Lewontin have written "the irrationalities of a scientifically sophisticated world come not from failure of intelligence but from the persistence of capitalism, which as a by-product also aborts human intelligence" (Dialectical Biologist, p. 208; see also their Biology Under the Influence [Monthly Review Press, 2007])."
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Re: Conservative Scientists & its Consequences
« Reply #2187 on: April 26, 2018, 11:00:34 PM »
"Hansen believes that Mercer lost funding opportunities as a result."

Mmmm. I'm not sure about this. None of the many scientists i have known at Byrd over the last few decades ever hinted at such a thing. Academically, Mercer was held in very high regard at the NSF; indeed his most outre behaviour was considered to be his habit of doing field studies in the nude. (But perhaps not in Antarctica ... )

sidd

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Re: Conservative Scientists & its Consequences
« Reply #2188 on: April 27, 2018, 12:48:05 AM »
"Hansen believes that Mercer lost funding opportunities as a result."

Mmmm. I'm not sure about this. None of the many scientists i have known at Byrd over the last few decades ever hinted at such a thing. Academically, Mercer was held in very high regard at the NSF; indeed his most outre behaviour was considered to be his habit of doing field studies in the nude. (But perhaps not in Antarctica ... )

sidd
While I have no special insights as to whether Mercer lost funding opportunities, or not; I find it difficult to believe that science funding is not influenced by scientific reticence, and Hansen's experience cited below, presents at least one example that supports my belief:

"Hansen points to his own experience. In 1981, based on the first reliable estimates of average global temperature by NASA, he pointed to the dangers of global warming from fossil fuel use. The result: his research group had some of its funding pulled by the Department of Energy, which specifically criticized aspects of that paper."
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Re: Conservative Scientists & its Consequences
« Reply #2189 on: April 27, 2018, 08:41:16 AM »
"Hansen believes that Mercer lost funding opportunities as a result."

Mmmm. I'm not sure about this. None of the many scientists i have known at Byrd over the last few decades ever hinted at such a thing. Academically, Mercer was held in very high regard at the NSF; indeed his most outre behaviour was considered to be his habit of doing field studies in the nude. (But perhaps not in Antarctica ... )

sidd


Is it reasonable to assume then that Mercer was one who both in his writings, and in his field research, was willing to expose himself to the keen observation of his peers?  8)
Terry




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Re: Conservative Scientists & its Consequences
« Reply #2190 on: April 27, 2018, 05:51:50 PM »
Personally, I find it disturbing that consensus climate science provides technical arguments to policy makers who want to maximize capitalist profits by delaying cuts in carbon emissions for as long as possible and then try to achieve the Paris Agreement targets by assuming the use of unverified negative emission technologies, see:

Title: "Meeting Paris Agreement Targets Will Take Massive Cuts in Emissions"

https://www.bloomberg.com/news/articles/2018-03-26/meeting-paris-agreement-targets-will-take-massive-cuts-in-emissions

Extract: "If those targets—between 1.5 to 2 degrees Celsius (2.7 to 3.6 Fahrenheit)—are overshot, the consequences would likely require both drastic cuts to emissions and geoengineering efforts to remove carbon from the atmosphere, according to the paper by Katsumasa Tanaka at the National Institute for Environmental Studies in Japan and Brian O’Neill at the U.S. National Center for Atmospheric Research."

See also: "The Shared Socioeconomic Pathways and their energy, land use, and greenhouse gas emissions implications: An overview"

https://www.sciencedirect.com/science/article/pii/S0959378016300681
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Re: Conservative Scientists & its Consequences
« Reply #2191 on: April 27, 2018, 07:47:29 PM »

Extract: "If those targets—between 1.5 to 2 degrees Celsius (2.7 to 3.6 Fahrenheit)—are overshot, the consequences would likely require both drastic cuts to emissions and geoengineering efforts

The carbon countdown clock (https://www.mcc-berlin.net/fileadmin/data/clock/carbon_clock.htm) suggests that the 1.5 degrees target is kaput already. The 2 degrees target requires carbon emissions cuts far beyond what is currently happening or even planned in principle.

That clock is also built on the assumption that there are no gorillas or elephants in the room.

The entire world political system has a child's faith in technology finding the answer big-time and quick-time.

Ho hum.
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Re: Conservative Scientists & its Consequences
« Reply #2192 on: April 27, 2018, 09:00:38 PM »
Personally, I find it disturbing that consensus climate science provides technical arguments to policy makers who want to maximize capitalist profits by delaying cuts in carbon emissions for as long as possible and then try to achieve the Paris Agreement targets by assuming the use of unverified negative emission technologies, see:

Title: "Meeting Paris Agreement Targets Will Take Massive Cuts in Emissions"

https://www.bloomberg.com/news/articles/2018-03-26/meeting-paris-agreement-targets-will-take-massive-cuts-in-emissions

Extract: "If those targets—between 1.5 to 2 degrees Celsius (2.7 to 3.6 Fahrenheit)—are overshot, the consequences would likely require both drastic cuts to emissions and geoengineering efforts to remove carbon from the atmosphere, according to the paper by Katsumasa Tanaka at the National Institute for Environmental Studies in Japan and Brian O’Neill at the U.S. National Center for Atmospheric Research."

See also: "The Shared Socioeconomic Pathways and their energy, land use, and greenhouse gas emissions implications: An overview"

https://www.sciencedirect.com/science/article/pii/S0959378016300681


Maybe it will have to get worse first, so that their capital starts to evaporate. The moment that's the starting point, a lot can be don i think. But it want come from itself. To much influence from everywhere. Maybe we are not that far off. If you look at the land from the west of Africa to Japan. It's almost everywhere warmer than average. That can only have an impact on the Arctic. The heat that's going to move over Russia, will go far north of Svalbard. And other palaces. The oceans  contain more heat every year . Where will that lead us ?

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Re: Conservative Scientists & its Consequences
« Reply #2193 on: April 27, 2018, 10:19:18 PM »
  • our current top of atmosphere radiation imbalance is 0.9W/meter-squared, this correlates to 0.8C with an ECS of 3.3
  • Current fossil fuel atmospheric pollution is masking over 0.9C of warming
  • The climate models used in these studies do not include emissions from melting permafrost and are underestimating carbon cycle land based feedbacks by over 300 GtC under >2C of globally averaged warming
  • 2017 was 1.1C above pre-industrial with no El Nino to provide extra warming

you do the math
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Re: Conservative Scientists & its Consequences
« Reply #2194 on: April 28, 2018, 06:15:40 PM »
This paper and attached image reminds me of an exchange I had with the indomitable Ned_W last year on the projections of expected mortality in Africa under a warming scenario.

discussion here:  https://forum.arctic-sea-ice.net/index.php/topic,1053.msg126113.html#msg126113

Paper Here: https://www.nature.com/articles/s41558-018-0145-6

See attached image
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Re: Conservative Scientists & its Consequences
« Reply #2195 on: April 28, 2018, 09:52:00 PM »
I am curious as to how they arrived at those values.  This recent paper shows that North Africa has warmed at less than the global rate in winter over the past century.

http://www.atmos.umd.edu/~nigam/JCLIM.African.Sahara.Desert.Expansion.published.29March2018.pdf


jai mitchell

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Re: Conservative Scientists & its Consequences
« Reply #2196 on: April 28, 2018, 10:28:19 PM »
I am curious as to how they arrived at those values.  This recent paper shows that North Africa has warmed at less than the global rate in winter over the past century.

http://www.atmos.umd.edu/~nigam/JCLIM.African.Sahara.Desert.Expansion.published.29March2018.pdf

Figure 2 shows that the warming in winter has actually been slightly higher and the summer warming was much more than the warming through 2013 of about 0.8C.
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Daniel B.

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Re: Conservative Scientists & its Consequences
« Reply #2197 on: April 30, 2018, 02:39:30 PM »
I am curious as to how they arrived at those values.  This recent paper shows that North Africa has warmed at less than the global rate in winter over the past century.

http://www.atmos.umd.edu/~nigam/JCLIM.African.Sahara.Desert.Expansion.published.29March2018.pdf

Figure 2 shows that the warming in winter has actually been slightly higher and the summer warming was much more than the warming through 2013 of about 0.8C.

Figure 2 shows slightly higher warming from Algeria west.  Central and eastern Sahara showed lower.

AbruptSLR

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Re: Conservative Scientists & its Consequences
« Reply #2198 on: April 30, 2018, 04:54:31 PM »
I am curious as to how they arrived at those values.  This recent paper shows that North Africa has warmed at less than the global rate in winter over the past century.

http://www.atmos.umd.edu/~nigam/JCLIM.African.Sahara.Desert.Expansion.published.29March2018.pdf

Figure 2 shows that the warming in winter has actually been slightly higher and the summer warming was much more than the warming through 2013 of about 0.8C.

In related research:

Weber, T. et al. (2018) Analyzing Regional Climate Change in Africa in a 1.5, 2, and 3C Global Warming World, Earth’s Future, doi/abs/10.1002/2017EF000714

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2017EF000714

Abstract: "At the 21st session of the United Nations Framework Convention on Climate Change Conference of the Parties (COP21) in Paris, an agreement to strengthen the effort to limit the global temperature increase well below 2°C was decided. However, even if global warming is limited, some regions might still be substantially affected by climate change, especially for continents like Africa where the socio‐economic conditions are strongly linked to the climatic conditions. In the paper we will discuss the analysis of indices assigned to the sectors health, agriculture, and infrastructure in a 1.5, 2, and 3°C global warming world for the African continent. For this analysis an ensemble of 10 different general circulation model‐regional climate model simulations conducted in the framework of the COordinated Downscaling EXperiment for Africa was investigated. The results show that the African continent, in particular the regions between 15°S and 15°N, has to expect an increase in hot nights and longer and more frequent heat waves even if the global temperature will be kept below 2°C. These effects intensify if the global mean temperature will exceed the 2°C threshold. Moreover, the daily rainfall intensity is expected to increase toward higher global warming scenarios and will affect especially the African Sub‐Saharan coastal regions."
See also:

Title: " Mapped: African heatwaves could increase ‘five-fold’ with 3C of global warming"

https://www.carbonbrief.org/mapped-african-heatwaves-could-increase-five-fold-with-3c-of-global-warming

Extract: "Although the effect of climate change on rainfall in Africa may be still unconfirmed, the study does highlight that limiting global warming to 1.5C would “make sense” for African nations, he adds:

“There is a large difference between the scale of impacts expected at 1.5 and 2C, especially for temperature. Therefore it makes sense to strengthen the efforts to limit global temperature increase as much as possible.”"
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Daniel B.

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Re: Conservative Scientists & its Consequences
« Reply #2199 on: May 01, 2018, 01:46:45 PM »
That is odd.  Most reports state that the tropics have exhibited the least changes, and will be the least effected.  It is the higher latitudes that will experience above average changes.