six degrees

[crandles]

Title of a book by Mark Lynas, often recommended as reading for some courses.

Here is a six minute video:

[wili]

I just assigned it for two of my classes. It seems important to me that the young know what is going to be coming at them at this point.

[AbruptSLR]

The following link leads to a blog post at the Union of Concerned Scientists, indicating that over half of all carbon dioxide emissions since the beginning of the industrial revolution (in 1751) have occurred since 1988, when James Hansen testified to the US Congress about the seriousness of the Global Warming problem (see attached figure, the associated following caption and quote).  My concern is that the general public thinks that since we made it from 1751 to now more or less OK, we may as well continue on a BAU pathway; which can only lead to disaster.

http://blog.ucsusa.org/global-warming-fact-co2-emissions-since-1988-764

Caption: "More than half of all industrial carbon dioxide emissions have been released since 1988. Image: Union of Concerned Scientists"

Quote regarding the findings of the Global Carbon Project, GCP: "The GCP estimates that in 2014, we will release a record 37 gigatons (GT) of carbon dioxide to the atmosphere from burning coal, oil, and natural gas, and manufacturing cement. That’s a 2.5 percent increase over emissions in 2013, itself a record year. This brings the total industrial carbon dioxide emissions since 1751 to an estimated 1480 Gt by the end of this year. And, remarkably, more than half of these emissions, 743 Gt, or 50.2 percent, have released just since 1988."

[AbruptSLR]

As an elaboration on my prior post (Reply #2) see the links and the extract below, which further delineate some of the challenges of getting off our current BAU pathway (for radiative forcing):

http://vitalsigns.worldwatch.org/vs-trend/greenhouse-gas-increases-are-leading-faster-rate-global-warming

See also:
http://www.investorideas.com/news/2014/renewable-energy/12151.asp

Extract: "As in 2013, the primary emitters in 2014 from the combustion of fossil fuels are expected to be China (28 percent), the United States (14 percent), the European Union (10 percent), and India (7 percent). In emissions per person, however, the United States ranks first with more than twice the per capita emissions of China, ranked second. There is a continued geographic shift in emissions from industrialized to developing countries.
The three other major greenhouse gases responsible for climate change are methane, nitrous oxide, and chlorofluorocarbons. Natural gas production and agriculture are major contributors of methane, a super-potent gas that traps 86 times the heat of CO2. Satellite photos show that methane leakage from the drilling and pipeline delivery of natural gas offsets any CO2 benefits that natural gas may bring over coal during combustion and use.
Energy supply, industrial processes, forestry, agriculture, and transportation account for the majority of greenhouse gas emissions. An expanding world population and the growth of developing-country economies contribute to the rising slope of emissions. And deforestation not only generates carbon emissions from the burning of forest residues, but also reduces the capacity of forests to capture carbon. Flattening the emissions curve to slow the rate of global climate change requires increasing the efficiency of energy production, transmission, and consumption; switching to renewable energy sources for electricity generation and transportation; and using non-fossil-fuel-based feedstocks for chemical production, among other actions."

[wili]

This thread is as good a place as any for this: http://thinkprogress.org/climate/2014/12/16/3604181/climate-pledges-not-enough-for-2c/

Latest International Climate Pledges Still Fall Short of 2°C Goal

For a brief history of the 2 degree 'guardrail,' see: https://www.skepticalscience.com/2-degrees-history.html (Basically, some economist just pulled it out of his...)

There's an enlightening and sobering graph that someone posted in the comment section:




ASLR, from your 'extract':

Flattening the emissions curve to slow the rate of global climate change requires increasing the efficiency of energy production, transmission, and consumption...

Unfortunately, as Jevons showed long ago (and has been demonstrated in the real world many times since, increased efficiency (alone) does not necessarily reduce overall use, and it can even perversely lead to increased use.

[AbruptSLR]

ASLR, from your 'extract':

Flattening the emissions curve to slow the rate of global climate change requires increasing the efficiency of energy production, transmission, and consumption...

Unfortunately, as Jevons showed long ago (and has been demonstrated in the real world many times since, increased efficiency (alone) does not necessarily reduce overall use, and it can even perversely lead to increased use.

wili,

Good points.  I agree that without adding something like a carbon fee & dividend plan that merely increasing efficiency is not going to be sufficient to fix our problems.  Indeed, with the rest of the developing world seeing how China made a great leap forward economically on the back of cheap fossil fuel, it is difficult to see the world making sufficient cuts to stay below a 4 to 6 C global temperature increase without large payments from the developed world to the developing world to ease their transition to low carbon economies (together with carbon fee & dividend plans in all developed countries).

Best,
ASLR

[wili]

I am largely in agreement, ASLR. There is a bit of a shift now, though, among many developing nations who are seeing that the ill effects of GW will be hitting them first and hardest. The Philippines in particular seems to have shifted to a position, in print at least, that reducing GW is a priority. Haiyan and other extreme events have helped to wake up both the people and the policy makers.

[Neven]

Title of a book by Mark Lynas, often recommended as reading for some courses.

Here is a six minute video:

My impression is that Lynas is dialing back on his previous warnings. Yesterday I read an article by a Dutch skeptic that Lynas is an example of the new Greens, or Ecomodernists. Does anyone know more about this?

[AbruptSLR]

Neven,

I do not know much about Mark Lynas; however, according to the linked article, Mark has softened his stance on GMO's but not on Climate Change (see extract below):

http://www.desmoinesregister.com/story/money/agriculture/2014/12/03/former-gmo-opponent-says-science-supports-crop/19852621/


Extract: :Mark Lynas was once among anti-GMO activists tearing out canola, sugar beets, maize and other crops. Now he's speaking in favor of genetically modified crops.

What changed his mind? Climate change, Lynas told members of the Iowa Farm Bureau Federation, attending the group's annual convention this week in Des Moines.

Looking at the science surrounding climate change, "the science was strong and very compelling," said Lynas, who is from Great Britain. But he discovered "the science was clear and equally compelling on the GMO issue, particularly on the safety issue."

For example, he pointed to statements from the American Association for the Advancement of Science: "The scientific evidence is clear. Global climate change caused by human activities is occurring and is a growing threat."

And the association's message on GMOs was equally clear, he said. "Crop improvement by the modern techniques of biotechnology is safe."

"There I was, in a completely inconsistent position, saying to everyone who was a climate change denier, 'the science is clear. This is what 97 percent of scientists agree' " about, he said. "But, oh no, on GMOs you've got to ignore the science.""

[Lennart van der Linde]

I think Lynas also supports nuclear energy now, like Monbiot, while opposing it in the past, also like Monbiot. And unlike Monbiot he seems to think economic growth is still possible and necessary, not only in developing countries, but also in developed countries.

[AbruptSLR]

For a given pulse of CO₂ emissions that linked (open access) reference indicates that the maximum mean global surface temperature increase will occur after about one decade (see also the attached image). Hopefully, this information will help people to believe that they will see the fruits of their labor to restrict CO₂ emissions, within their life-times:

Katharine L Ricke and Ken Caldeira, (2014), "Maximum warming occurs about one decade after a carbon dioxide emission", Environ. Res. Lett. 9 124002, doi:10.1088/1748-9326/9/12/124002

http://iopscience.iop.org/1748-9326/9/12/124002/article

Abstract: "It is known that carbon dioxide emissions cause the Earth to warm, but no previous study has focused on examining how long it takes to reach maximum warming following a particular CO2 emission. Using conjoined results of carbon-cycle and physical-climate model intercomparison projects (Taylor et al 2012, Joos et al 2013), we find the median time between an emission and maximum warming is 10.1 years, with a 90% probability range of 6.6–30.7 years. We evaluate uncertainties in timing and amount of warming, partitioning them into three contributing factors: carbon cycle, climate sensitivity and ocean thermal inertia. If uncertainty in any one factor is reduced to zero without reducing uncertainty in the other factors, the majority of overall uncertainty remains. Thus, narrowing uncertainty in century-scale warming depends on narrowing uncertainty in all contributing factors. Our results indicate that benefit from avoided climate damage from avoided CO2 emissions will be manifested within the lifetimes of people who acted to avoid that emission. While such avoidance could be expected to benefit future generations, there is potential for emissions avoidance to provide substantial benefit to current generations."

[wili]

Yes, my understanding is that Lynas has come out in favor of nuclear. I hadn't known about his stance on GMOs. The difference for me between these things and GW is in the latter case, scientists are warning us about a future danger. There is no realistic monetary or other reason for them to do so.

In the cases of nukes and GMO, science is telling us something is not a danger, and at least some of those scientists have reasons to do so. Given the least-drama predilection of most scientists, when they actually do present warnings, and not just as individuals but every established organization of them, I take notice.

It is the difference between someone rather trustworthy looking around the corner and seeing a large car careening down the street in this general direction. I am strongly inclined to take action on that information.

Someone telling me that he can't see anything coming down the road from where he's standing, on the other hand, does not leave me completely convinced that no danger can come from loitering about in the road at that spot--there could be any number of things outside of my watchers view that could be a concern. And the things I find to be of concern may not be those that he does. And I happen to know that this particular bloke absolutely hates to be someone who anyone would every accuse of 'crying wolf'...

[AbruptSLR]

I would like to note that James Hansen also supports nuclear power, and apparently he considered Global Warming a greater danger.

Also, I would like to note that in my own opinion, Global Warming, makes the risks worse for all other issues including nuclear power, warfare, disease, food productions, water supply, etc. as Global Warming can undermine the very roots of modern society.  Therefore, no matter what ones opinion is about other issues, a rational person who cares about future generations, cannot allow Global Warming to get out of hand.

[viddaloo]

Yup, we definitely should have done something to stop it, but you know, we had the Dynasty and Falcon Crest and the Charles & Diana wedding and all this other stuff that consumed us and seemed so much more important at the time.

[tombond]

Many good comments!

By any measure climate change caused by human activity, mainly burning fossil fuels is the biggest threat to the survival of human civilisation and perhaps even the survival of the human species.

I like this comedy video from The Newsroom on the danger of climate change as it has more than a hint of truth. 

To reduce the impact of climate change requires the speedy transition to non fossil carbon energy on a global scale, an almost impossible task.  Currently about 14 billion tonnes of fossil fuel is mined every year emitting near 40 billion tonnes of greenhouse gases, increasing by 2.5% annually (average since 1995).  Total accumulative emissions dumped in the atmosphere since the late 18th century will therefore likely double before 2050.  http://www.pik-potsdam.de/~mmalte/rcps/

To have any chance of averting the worse effects of climate change requires every emission reducing technology and energy reduction measures that is available.

The bottom line is we need them all and in the long term it does not matter which technology is the most successful, as long as emissions are reduced, but all have obvious limitations and issues.
•   Energy efficiency and energy restriction will help reduce, but not replace fossil fuel use.
•   Many renewable energy sources are climate controlled and only available when the resource is available requiring backup, currently this is mainly fossil fuel.
•   Biomass and hydro are reliable sources of energy but are limited by the resource available.
•   Nuclear technology is likely to be our best option particularly fast reactor technology, but has perceived risks which must be weighed against the real risk of climate change. 
See Ben Heard’s video clip on this issue. 

Other interesting data.
One tonne of uranium fuel replaces about 20,000 tonnes of coal.
400 nuclear reactors worldwide produce 5% of the world’s energy, saving 2 billion tonnes of CO2 emissions and creating just 9000 tonnes of nuclear waste annually.  Compare this to 40 billion tonnes of GHG waste from fossil fuels, which is just dumped into the atmosphere.
Annual deaths from carbon pollution is 7 million, see WHO report.  http://www.who.int/hia/green_economy/reducing_air_pollution/en/
Compared to total deaths from radiation as a result of nuclear accidents of about 50, see UN Chernobyl and Fukushima reports.  http://www.unscear.org/unscear/en/index.html
The first fast reactor prototype (the EBR1) was constructed in 1951 and the programme ran almost continually up to 1994 proving to be passively safe and very efficient.  http://www.ne.anl.gov/About/reactors/frt.shtml

The total nuclear waste stockpile after 50 years of civilian nuclear energy generation is just 270,000 tonnes.
Fast reactors can use this nuclear waste as fuel, reducing its volume 20 fold requiring storage for just a few hundred years. 

[AbruptSLR]

While I applaud almost all efforts to limit climate change, to be realistic I would like to note that:

A. The current UN climate change process is inclusive; which means it will be slow and like will produce relatively weak limits on climate change (see the linked article).

http://www.businessinsider.com/problems-with-un-lima-climate-plan-2014-12

B. After Fukashima the industry for any new nuclear power in the USA is almost dead for the next few decades.

C. The conventional fossil fuel industry is already striking back (ie "The Empire Strikes Back") by pumping large quantities of crude oil; which at least Richard Branson believes are focused not only on fracking operations, but also to cripple renewal energy operations (see link and associated quote below).  I will also note that if non-conventional fossil fuels (including fracking and tar sands) fight back against the conventional fossil fuel industry then the world may see relatively low fossil fuel price for many years to come.

http://www.theguardian.com/environment/2014/dec/16/cheaper-oil-could-damage-renewable-energies-says-richard-branson

Quote: "Saudi Arabia is encouraging the dramatic collapse of oil prices in order to damage the surging global clean energy industry, British entrepreneur Richard Branson has claimed. “They have done it before and it hurt. They don’t just want to damage the US fracking industry, but also the clean energy business. The collapse of oil prices is going to make it much more difficult for clean energy,” he warned, speaking from the Caribbean island of Necker."

[Ymir]

For a given pulse of CO₂ emissions that linked (open access) reference indicates that the maximum mean global surface temperature increase will occur after about one decade (see also the attached image). Hopefully, this information will help people to believe that they will see the fruits of their labor to restrict CO₂ emissions, within their life-times:

Katharine L Ricke and Ken Caldeira, (2014), "Maximum warming occurs about one decade after a carbon dioxide emission", Environ. Res. Lett. 9 124002, doi:10.1088/1748-9326/9/12/124002

http://iopscience.iop.org/1748-9326/9/12/124002/article


Abstract: "It is known that carbon dioxide emissions cause the Earth to warm, but no previous study has focused on examining how long it takes to reach maximum warming following a particular CO2 emission. Using conjoined results of carbon-cycle and physical-climate model intercomparison projects (Taylor et al 2012, Joos et al 2013), we find the median time between an emission and maximum warming is 10.1 years, with a 90% probability range of 6.6–30.7 years. We evaluate uncertainties in timing and amount of warming, partitioning them into three contributing factors: carbon cycle, climate sensitivity and ocean thermal inertia. If uncertainty in any one factor is reduced to zero without reducing uncertainty in the other factors, the majority of overall uncertainty remains. Thus, narrowing uncertainty in century-scale warming depends on narrowing uncertainty in all contributing factors. Our results indicate that benefit from avoided climate damage from avoided CO2 emissions will be manifested within the lifetimes of people who acted to avoid that emission. While such avoidance could be expected to benefit future generations, there is potential for emissions avoidance to provide substantial benefit to current generations."

I have repeatedly read that there is a 30 to 40 year time lag between carbon emission and the warming it causes, this isn't the case then?

[jai mitchell]

The curve shown is the temperature response rate, not the equilibrium temperature response.  What it means is that, for a given pulse of CO2, the rate of heat effects will not become fully engaged for about 10 years.  After that happens then the earth will be warming at its maximum rate until a new equilibrium is reached. 

It used to be that this lag time was neglected in the models it still may be in some cases, but in an environment of increasing rates of CO2 emissions it means that we may be experiencing a warming rate that is from more than a decade ago (if one also includes other negative forcing factors such as anthropogenic aerosols).

the curve that shows the temperature response to CO2 looks like this.

[LRC1962]

I do think that it should be pointed out that at least according to this argument, CO2

turnover takes 500-1000ish years

. Meaning however we produced that CO2 since the beginning of the industrial revolution; farming, deforestation, FF, animals..., we are still stuck with those same number of molecules already produced for a minimum of another 300 years. You then have to now include all the CO2 being released by positive feedbacks.
The way things are being presented by the media is that if we were to stop CO2 production now, somehow that means we can return to pre industrial levels. or if we cut back then return to some level between then and now.  Not quite.

[Ymir]

So the 30-40 year lag simply isn't true? And does all carbon not re absorbed continue warming for a minimum of 500 years? I have only recently of atmospheric carbon's 1000 year lifespan. Does that mean we are going to get anthropogenic warming for at least 500 years from today? In which case, Guy McPherson sounds closer to being correct than Hansen or Mckibben?

I apologise if my questions might be a bit basic, I'm not a scientist and on a very steep learning curve on the forum!

[crandles]

So the 30-40 year lag simply isn't true? And does all carbon not re absorbed continue warming for a minimum of 500 years? I have only recently of atmospheric carbon's 1000 year lifespan. Does that mean we are going to get anthropogenic warming for at least 500 years from today? In which case, Guy McPherson sounds closer to being correct than Hansen or Mckibben?

I apologise if my questions might be a bit basic, I'm not a scientist and on a very steep learning curve on the forum!

I am no expert but

This is a new paper and it may take time for experts to assess its importance.

Even if the papers results are accepted as sound, I think it should be noted that the paper uses large pulses of CO2 like an instantaneous quadrupling. The real world isn't like that, emissions occur fairly steadily. So when you are a long way into a steady rise and then you choose between two pathways that increasingly separate what happens? If the response time to instantaneous step change is 10 years as per the paper you linked then you certainly don't see anything within 10 years. If the two pathways stay close for the first 10 years then the cumulative emissions for each pathway are still almost entirely due to past emission choices and you don't see anything for 20 years. As the pathways separate further then the cumulative emissions start to differ. Even though they differ, the noise in the system may well mean that the change is not detectable through to 30 to 40 years.

So it seems quite possible to me that the papers 10 years is correct, but also that
the effect of changes now are not detectable until 30 to 40 years hence is also correct.

[Csnavywx]

I think by "maximum warming", they really mean maximum rate of warming over time from a particular emission of CO2, as in the function maximizes at 10 years and then slowly tails off afterwards (hence the large and skewed distribution towards longer values). The effective equilibrium response lags behind the maximum rate a good distance, so the 30 year lag you see quoted prior to this paper is probably referring to that.

[LRC1962]

There are two different issues at hand here. The 40-50 lag time time is the the time for temperatures to respond to what is in the system. For example the 400 ppm you have today will not affect global temperatures until 2050-2060. The temperatures we have today are only responding to 1960-1970 CO2 levels.
The second number has also been discussed many times, I was just reminding people, and that is how long a molecule of CO2 remains in the system. In this case the only way to get rid of it is for it to get buried in the oceans via the Thermohaline currents by getting it into the very deep oceans and let the critters there sequestering it as a layer of limestone or something similar, or by sequestering it as a new layer of coal or oil on land. In other words once CO2 is created the only true way to get rid of it is to get rid of the oxygen have carbon attach itself to either water (hydrocarbons) or calcium (lime) and bury it.
On land forests are vital in that they are the main way nature has a chance to get a layer of coal or oil down. at sea it can either be oil/coal, but mainly lime stone. As the article states CO2 is a very difficult molecule to get rid of because nature has so many ways of creating it itself and is the main waste product of most of nature.
Edit: That is why when it comes to CO2 scientist say that further rise in temperatures are already in the system, but not stopping producing any more is just going to make matters worse.

[Ymir]

So, is this different to what Jai Mitchell is saying? Heat effects becoming "fully engaged" after ten years?

In layman's terms we are only now experiencing warming from carbon released in the 70s?

[LRC1962]

I have seen some to suggest only 30 years, but the consensus is between 40-50 years so yes we are seeing the results of 1970. Puts a whole new look at things doesn't it?
The debate among scientist are not these numbers, the debate is how much nature can take before it really bites us hard. Such as sea level rise. Temperatures get too hot for plants to grow. Too much CO2 and plants grow large and fast but have very little nutrition in them. Then weather gets really strange.
All these things have very deadly consequences for humans, we just do not know when or how fast it all will happen.
Right now we seem to have two extremes. The IPCC which is generally seen as too conservative as it is mainly a political paper and Guy MacPherson who if right we are in very serious trouble, but I think is on the outer fringe of the other extreme. The truth IMO is somewhere in the middle. The problem is where that spot is. The closer to IPCC you get the more time we have to act. The closer you get the GM the less chance we have of doing anything on time.

[Yuha]

Here is an excerpt from the Ricke&Caldeira paper that explains what they mean by the 10 years until maximum:

"A pulse emission of CO2 results in a stepwise increase in atmospheric CO2 content, followed by a slow decrease as the CO2 is taken up by the oceans and terrestrial biosphere. Global temperature rises in response to the CO2 forcing, but with a lag of about a decade due to the thermal inertia of the upper layers of the ocean. The maximum temperature is reached when the ever-decreasing rate of warming in response to the increase in radiative forcing is balanced by the slowly decreasing magnitude of radiative forcing of atmospheric CO2."

But they also say this:

"For many impacts, such as changes to natural ecosystems, degradation is the result of the cumulative effects of consecutive years of warming or precipitation change (Parmesan and Yohe 2003). Ice sheet melting can persist for thousands of years following a warming (Huybrechts et al 2011). As such, even if maximum warming occurs within a decade, maximum impact may not be reached until much later. From this perspective, Steven Chu’s statement that today’s damage ‘will not be seen for at least 50 years’ may well be accurate."

[LRC1962]

Ricke&Caldeira seem to be saying that they think the direct impact of CO2 to temperature change is only 10 years, but they argue that the 50 year lag only comes into effect when you involve feedbacks.
They seem to be also talking from the standpoint of a pulse of CO2, meaning going up say 5 ppm and staying there and that no feedbacks will happen. Seems to be more a thought lab experiment rather then what is happening on the ground so I would stick with 50 year lag as we are seeing all the feedbacks the others of mentioned and we are not in a pulse we have a wide open tap.

[AbruptSLR]

As I made the initial post (Reply #10) about Ricke & Caldeira (2014) [R&C], I feel some sense of responsibility for trying to clarify some of the confusion raised by this paper (which has a nice video if you follow the initial link).  However, as I have limited time now, I will make a few quick comments here & then I try to comeback & add some background commentary later.

First, R&C's methodology is fully consistent with AR5, so if all you want is an IPCC projection of the future that errs on the side of least drama then just look at the first attached image and note that the video narrated by Mark Lynas at the start of this post assumes the 90% CL level for RCP 8.5, which is essentially the BAU pathway that we are currently following.

Second, R&C's pulse analogy is very similar to the instantaneous CO₂ doubling assumed to calculate TCR or ECS (see the second attached image with the lower curve for a 1%/year rate of increase up to a CO₂ doubling and the upper curve for a 1%/year rate of increase up to  quadrupling of CO₂), or the longer-term Earth Systems Sensitivity, ESS [not shown]; except that it adds the influence of the carbon cycle and the range of uncertainty for climate sensitivity, which results in the shorter time to peak temperature rise than for the time shown in the second attached figure (from the Third Assessment Report, TAR).

Again R&C is not saying anything new or different from AR5 except that as indicated by the following extract from their summary, decision makers tend to heavily discount the impacts of climate beyond some threshold such as a political cycle, or their own personal life-time; therefore, [without ignoring the 50-year period for major damage associated with TCR, with AR5's emission budget guidance is based on {not on ECS or ESS, which have longer periods of impact}] decision makers [including the general public when they vote] should not so heavily discount the impart of raising global-mean surface temperature, as they will see the benefit of working to prevent any little GHG pulse in a relatively short period of time.

Extract: "The primary time lag limiting efforts to diminish future climate change may be the time scales associated with political consensus (Victor 2011) and with energy system transitions (Smil 2010), and not time lags in the physical climate system. While the relevant time lags imposed by the climate system are substantially shorter than a human lifetime, they are substantially longer than the typical political election cycle, making these delays and their associated uncertainties important, both economically and politically. Nonetheless, our study indicates that people alive today are very likely to benefit from emissions avoided today."

Edit: I note that jai's temperature curve (see Reply #17) very likely assumes the same 1%/year rate of increase of CO2 assumed by TAR in the second attached image, thus explaining why his timeframe is relatively long as compared to the instantaneous pulse assumed by R&C 2014.

[jai mitchell]

The CO2 forcing factor is instantaneous as it has been directly measured and fluctuates directly with the annual variation in CO2 abundance in the earth's atmosphere.  however, Ricke and Caldeira showed that the feedback response from CO2 does not reach its full effect of warming rates until about 10 years.  This is primarily due to the thermal inertia of the surface layer of the world's oceans. But other factors, like climate sensitivity, are also involved. 

http://iopscience.iop.org/1748-9326/9/12/124002/article

After full warming rates are achieved, the earth will continue to warm and this longer term warming rate will increase as slower feedbacks such as arctic sea ice albedo and cloud effects add to the forcing rates.  But this is beyond the paper of Ricke and Caldeira. 

The whole point of this is to show that the lag time of current emissions, coupled with a dampening factor of aerosol forcing is keeping us at a warming response rate that is closer to the equivalent forcing (CO2e) value of 1990. 

In other words, once we massively cut our aerosols we will likely be facing a residual warming increase over the next ten years that is equal to almost 30 years of residual emissions.

[AbruptSLR]

I briefly add the following to my last post (Reply #27):

(a) The anthropogenic climate change problem is 100% due to a lack of human willpower to face reality both today and for at least the past 50-years; which is why according to MIT: "The latest forecasted CO₂-eq for April 1, 2015 is 485.48ppm"; which is near to the 90%CL RCP 8.5 scenario.  This explains why Ricke & Caldeira (2014) are attempting to encourage people to have the willpower to fight now rather than to follow the example of the "Greatest Generation" and the "Baby Boomers" to either say that the climate challenge can wait, or alternately that it is already too late to fix the problem so why try (or per some on this forum: "Let's accelerate the collapse").

(b) For the past 50-years the state elite have felt justified in ignoring the "fat-tail" of the climate change risk pdf; as reflected in the IPCC's use of essentially linear TCR-based projections until the state elite used-up all of the Carbon-Budget cited in AR5 (assuming that by the time the budget is used up that they will have gotten to net zero emissions and effectively learned to use geo-engineering (including both Negative Emissions Technology, NET, and Solar Radiation Management, SRM) in order to attempt to avoid the worse climate consequences.

(c) For many of the reasons cited in the following two linked threads, by June of 2015 the IPCC will decide whether the "fat-tailed" risks that they ignored when developing the AR5 Carbon-Budget (based on a 2C temperature rise limit) erred too far on the side of least drama, and whether now the IPCC should recommend a 1.5C temperature rise limit.

http://forum.arctic-sea-ice.net/index.php/topic,1053.0.html
&
http://forum.arctic-sea-ice.net/index.php/topic,1020.0.html


Postscript: The second figure (from TAR) in my last post just assumes that due to things like the majesty of human willpower and the good guidance of the Kyoto Protocol that the state elite would have limited CO2 emissions to 1% growth per year vs the 2 to 2.5% growth per year of CO2 (not to talk about other GHG's) that actual occurred after TAR was prepared.  Furthermore, this graph helps to illustrate why the state elite felt fully justified in ignoring the "fat-tail" of the risk pdf; however, their failure to act effectively in the meantime has caused this tail to become fatter with each passing year (& very soon it may well become a "dragon-tail").

[AbruptSLR]

The following linked reference (with an open access pdf) expands on my point that the IPCC is considering to adopt a 1.5C temperature rise limit:

Petra Tschakert (2015), "1.5°C or 2°C: a conduit’s view from the science-policy interface at COP20 in Lima, Peru", Climate Change Responses, 2:3  doi:10.1186/s40665-015-0010-z.

http://www.climatechangeresponses.com/content/2/1/3

Abstract: "An average global 2°C warming compared to pre-industrial times is commonly understood as the most important target in climate policy negotiations. It is a temperature target indicative of a fiercely debated threshold between what some consider acceptable warming and warming that implies dangerous anthropogenic interference with the climate system and hence to be avoided. Although this 2°C target has been officially endorsed as scientifically sound and justified in the Copenhagen Report issued by the 15th Conference of the Parties (COP) of the United Nations Framework Convention on Climate Change (UNFCCC) in 2009, the large majority of countries (over two-thirds) that have signed and ratified the UNFCCC strongly object to this target as the core of the long-term goal of keeping temperatures below a certain danger level. Instead, they promote a 1.5°C target as a more adequate limit for dangerous interference. At COP16 in Cancun, parties to the convention recognized the need to consider strengthening the long-term global goal in the so-called 2013–2015 Review, given improved scientific knowledge, including the possible adoption of the 1.5°C target. In this perspective piece, I examine the discussions of a structured expert dialogue (SED) between selected Intergovernmental Panel on Climate Change (IPCC) authors, myself included, and parties to the convention to assess the adequacy of the long-term goal. I pay particular attention to the uneven geographies and power differentials that lay behind the ongoing political debate regarding an adequate target for protecting ecosystems, food security, and sustainable development. "

[AbruptSLR]

In the way of additional background, since no later than the 1970's, GCMs only served to validate, and elaborate on, initial "closed-form" calculations.  Such "closed-form" calculations typically use an energy balance approach to calculate changes in global temperature.  In an energy balance approach, the earth must increase its longwave, LW, emissions to space in order to re-establish its energy balance due to changes in radiative forcing, deltaF (in W m-2), due to GHG concentrations, as a first approximation it can be assumed that this increased LW emission is proportional to the global surface temperature change deltaT, which give the equation:

deltaF = (lambda)(deltaT) + deltaQ

Where:       lambda = the climate feedback parameter (in W m-2C-1), and
                 deltaQ  =  the imbalance between the climate forcing and the response (in W m-2), which is dominated by ocean influence and thus is generally referred to as the ocean heat uptake (and is currently estimated to be 0.85 +/- 0.15 W m-2 and is currently dominated by the ocean heat uptake, but which is decreasing slightly with time at the as the Arctic Sea Ice is disappearing rapidly).  This term typically causes a 1 to 40-yr lag between time for a given change in a radiative forcing with fast feedback sensitivity and the final equilibrium change in temperature (the lag time for slow feedback sensitivity maybe say 40 to hundreds of years).

For a given radiative forcing, lambda is determined by two factors: (a) the Planck (blackbody) response of the Earth's LW emission, lambda_o which is approximately 3.8 W m-2C-1 and (b) any feedbacks that come into play as the Earth warms (in the absence of any feedback lambda = lambda_o ). 

For a coupled atmosphere-ocean global climate model the "climate feedback parameter" and [its inverse the "climate sensitivity parameter"] is an emergent property: it is not a model parameter, but rather a result of a combination of model physics and parameters.

Previous studies (including IPCC studies) suggest that the equilibrium climate sensitivity (or equilibrium global surface warming), ECS, to a doubling of atmospheric CO2, is 3 ^oC as the best mean estimate for the moderately stable Holocene period from the Last Glacial Maximum (LGM) to the present, with a 2 to 4.5 ^oC as the 66% probability range, and a nonzero probabilities for much higher values, the latter implying a small but significant chance of high-impact climate changes that would be difficult to avoid.  Nevertheless, it is important to note that the sensitivity during warming periods is generally higher than during cooling periods. Determination of the sensitivity during the current warming phase requires an understanding of the current feedbacks, which, maybe: more numerous, more positive, and faster responding, than for either cooling, or stable, phases of the climate.

The newest class of climate models are called Earth System Models, ESMs, incorporate many intermediate and slow respond sensitivity feedbacks; as well as changes in the CO2 (and other GHGs) sequestration capacity of the land and ocean (note in the past 50 years this sequestration has changed from about 60% to about 55%; and also changes in sources of GHG such as melting of the permafrost).  Therefore, we will likely need to wait for the findings of state-of-the-art ESMs, like ACME, before we have a reasonable approximation of the climate change risks that we are facing.  Until we have the final ACME projections, I recommend that we err on the side of caution instead of erring on the side of least drama.

[LRC1962]

@AbruptSLR: Many thanks for your fine response. My own attitude is prepare for the worst to happen and if anything else actually occur it as if I got a bonus and am very happy.

[Shared Humanity]

What if the "worst" is worse than you could have imagined?   

[AbruptSLR]

What if the "worst" is worse than you could have imagined?   

SH,
While I have made many posts about possible unsuspected climate change related Dragon King events, I thought that I would note that per the linked reference (see attached images) rapid ice melting is already moving the location of the Earth's rotational axis, and if/when the WAIS collapse occurs (possibly this century), we can expect a rather dramatic shift in the Earth's poles (also note that the Earth's magnetic pole is shifting rapidly in the opposite direction as the rotational pole).

Chen, J. L., C. R. Wilson, J. C. Ries, and B. D. Tapley (2013), Rapid ice melting drives Earth's pole to the east, Geophys. Res. Lett., 40, 2625–2630, doi:10.1002/grl.50552

http://onlinelibrary.wiley.com/doi/10.1002/grl.50552/abstract;jsessionid=DC0A43068ECB437A2C94A16B705A82BE.f02t03

Best,
ASLR

[Jim Hunt]

Lynas is an example of the new Greens, or Ecomodernists. Does anyone know more about this?

Mike Shellenberger "followed" "Snow White" and I on Twitter, so I have been doing my due diligence. As far as I can tell they're a bunch of shills for Big Oil. Here's the highlights of my latest adventure in Cloud Cuckoo Land:

Happily Engaging With Ecomodernists on Solar PV in Haiti

I wonder if Lynas is aware of that?

[Shared Humanity]

What if the "worst" is worse than you could have imagined?   

SH,
While I have made many posts about possible unsuspected climate change related Dragon King events, I thought that I would note that per the linked reference (see attached images) rapid ice melting is already moving the location of the Earth's rotational axis, and if/when the WAIS collapse occurs (possibly this century), we can expect a rather dramatic shift in the Earth's poles (also note that the Earth's magnetic pole is shifting rapidly in the opposite direction as the rotational pole).

Chen, J. L., C. R. Wilson, J. C. Ries, and B. D. Tapley (2013), Rapid ice melting drives Earth's pole to the east, Geophys. Res. Lett., 40, 2625–2630, doi:10.1002/grl.50552

http://onlinelibrary.wiley.com/doi/10.1002/grl.50552/abstract;jsessionid=DC0A43068ECB437A2C94A16B705A82BE.f02t03

Best,
ASLR

Great! Now I've got  something else  to worry about.

[Neven]

Lynas is an example of the new Greens, or Ecomodernists. Does anyone know more about this?

Mike Shellenberger "followed" "Snow White" and I on Twitter, so I have been doing my due diligence. As far as I can tell they're a bunch of shills for Big Oil. Here's the highlights of my latest adventure in Cloud Cuckoo Land:

Happily Engaging With Ecomodernists on Solar PV in Haiti

I wonder if Lynas is aware of that?

Thanks, Jim. I've also looked into it some more, and read a piece by Mark Lynas on the Ecomodernist webpage. It all sounds great, but it's lacking substance in my view. It's all words, no calculations or explanations how everything is going to become hunky dory, pure Green BAU, solving the problem without talking about the problem (because that apparently puts people off). I come away with the feeling that one of the goals is to put a taint on environmentalism (as if that's some homogenous movement).

I guess that this is Mark Lynas' most profitable career move. First jump on Al Gore's alarmist bandwagon, and then turn around and promote Soylent Green as the big solution. Everyone needs to make a living to pay the supermarkets, travel bureaus and Apple stores.

[Jim Hunt]

Everyone needs to make a living to pay the supermarkets, travel bureaus and Apple stores.

Speaking of which:

https://storify.com/jim_hunt/an-unpolarised-debate-about-money-for-skepticism

[jai mitchell]

Great! Now I've got  something else  to worry about.

The magnetic flip happens over several hundreds of years if I remember correctly, while "quick" on geological scales, studies of magnetic rocks have shown this has occurred on a regular basis and that it doesn't effect the earth in any significant way (wrt human/environmental consequences)

the shift in the earth's wobble due to ice loss will be imperceptible.  so, don't worry :-)

[Jim Hunt]

I took umbrage at being Storified then blocked by Michael Shellenberger.

Hence here's a great new resource for BTI bashers the world over:

http://GreatEcomodernistCon.info/2015/07/hello-world/

[Jim Hunt]

I took umbrage at being Storified then blocked by Michael Shellenberger.

In the latest shock news from the Twittosphere Mark Lynas refuses to talk to me despite issuing a "plea for depolarisation", whilst Mike Shellenberger has unblocked me only to accuse me of engaging in "troll behavior":

https://twitter.com/MichaelBTI/status/647383234033123328