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nigelj at 07:25 AM on 28 September 2018New study reconciles a dispute about how fast global warming will happen
MAR @18, I interpreted DougC's comments @ 1 and elsewehere a little differently to you in some regards. However having read his comments again, I can see how they could be interpreted in the way you say. Perhaps they lacked a little clarity, but it is probably time pressure and he makes some good points, and does better than some people I can think of over at RC with their confused pessimistic rants.
He does indeed say a 3.4 degree warmer world is where we are going but I took this to mean if we are stupid enough to keep burning fossil fuels, surely a non controversial and self evident statement? But in hindsight, he could have helped his case if he had stated if we continue on business as usual scenario.
Unfortunately one of the denialist tricks is to post comments that we are doomed because warming is locked in, so theres no point doing anything. Doug isn't in that category, but I guess some people could interpret his comments that way and I guess this is what bothers you? Its something we all need to be aware of anyway.
I agree he was vague about how we get to a 12 degree world. But his sentiment was correct, and at least he wasn't claiming it could happen in our lifetimes as a couple of people have suggested.
You say "The response also talks of "much of the research" being "conservative" which is the sort of non-specif comment I truly hate. It gives license to ignore research and is thus anti-scientific. More usually the "conservative" label is attached to the IPCC assessment reports which again as a generalisation is anti-scientific."
Now I agree totally here, and feel the need to do a bit of a rant. Imho this all creates doubt and confusion about the research in the publics mind and undermines the credibility of the IPCC with the public. I wish people would word their criticisms a little more artfully and with some context or proviso's. In fact I dont see any evidence that the climate research is "conservative" in terms of specific papers, and at most one could argue that the conclusions the IPCC reach having reviewed all the papers are a little conservative, but this is not actually a bad thing, and I dont see it being "hugely" conservative.
The problem is more in the summary for policy makers, where some things appear to be left out or language watered down and imho its a serious concern. The same applies to this new report on paris timeframe issues. I hope you see this and enough links have been posted on the issues. It probably reflects trying to get agreement of multiple countries and their representatives, so its essentially political and is not an understatement of scientific knowledge, but that doesn't in any way justify it. The document ends up potentially creating a false impression and understating risks.
It is however a tough problem to solve. Like herding cats. However it's certainly not a reason to rubbish the entire IPCC reports or climate research, because once we do this we play right into the deniliasts hands because its music to their ears.
So on balance I do think there are some valid criticisms of the IPCC summary for policy makers, and things of a similar nature, but they need to be worded carefully, not in the brainless, emotive and naive way the usual suspects do. I think you yourself have bemoaned the lack of attention given to long term sea level rise.
Regarding the killing of all complex life. He should probably have said something like "all or most complex life". However I think for the purposes of his comment the definition of complex life is self evident enough.
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MA Rodger at 05:30 AM on 28 September 2018There's no empirical evidence
aleks @364,
(1) There are quite a few considerations when calculating the temperature of a no-GHG Earth. In the simplest calculation, the big variable would be albedo which is 0.12 on the moon and 0.3 on the GHG Earth. Assuming albedo can vary from zero to 0.3 yileds a S-B result of 278k down to 255k. (A no-GHG Earth could have a significantly different albedo to today's GHG Earth.) These simplest of calculations would yield lower temperatures if S-B is used for local temperature rather than global as the variations mean the hotter bits radiate more extra radiation than the colder bit reduced radiation.
The Moon temperature results from a body with wildly different rotation and lilely a greatly different non-GHG albedo. Strangely folk seem reluctant to provide an average lunar surface temperature. But if you use the numbers presented by Williams et al (2017) the average comes out as 253K.
The effect of a non-GHG atmosphere would add a little to heat loss it would presumably be a larger flux than today's GHG Earth's 17Wm^-2 flux as there would be a big temperature difference between the surface under the mid-day tropical sun and a fridged atmosphere, further reducing the non-GHG temperature. I would imagine that a non-GHG atmosphere would do little to move heat from the mid-day tropics to colder parts of the Earth.
The most involved approach to the calculation would be to turn a climate model onto the situation, something done by Lacis et al (2010). They find an average global temperature falling to 253K by 100 years after removing all GHGs (bar water vapour). The temperature is still falling even after 100 years. I would speculate that well beyond 100 years there will be a time when all the water in warmer latitudes which could be turned to water vapour would have fallen as snow over frozen latitudes, eventually emptying the tropical oceans and leaving a desert over the tropics (the only places warm enough for water) and thus water vapour would drop very greatly relative to the 100 year situation. Further, albedo would probably be higher due to the increased high latitude ice fields and oceanless tropics. All in all, I would suggest that the 100-year 253K temperature will reduce significantly more before equilibrium is reached.
(2) The "without the atmosphere" wording perhaps would be better put as "without GHGs." For no other reason, the assertion that a cold world would be "uninhabitable for humans" and "agriculture ... more or less impossible" would also apply to a "without the atmosphere" world how ever hot or cold it was.
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aleks at 02:46 AM on 28 September 2018There's no empirical evidence
I would like to comment on the two statements in this article.
1. « The laws of physics tell us that without the atmosphere, the Earth would be approximately 33oC cooler than it actually is”.
Two ways to find this temperature difference are known. The first way is based on the consideration of the Earth as an perfect black body and the application of the Stefan-Boltzmann equation (radiant heat emitted from a unit of area is directly proportional to the temperature (in K) in the 4th power). Although the Earth radiates not quite an ideal black body (uneven surface structure and different chemical composition), with the use of certain averaging (values of emitted radiant heat and albedo) it is possible to obtain the "effective temperature of the Earth" 254-255 K. This value is compared with the average temperature of the Earth, which is very conditional (if we take into account the continuous temperature changes in time and in different places on the Earth's surface) is assumed equal to 287-288 K.
The second way is to compare average temperatures on the Earth and on the Moon
while the average temperature on the Moon is estimated as -18 ° C:
LINK
Obviously, to consider these semiempirical calculations based on the “laws of physics”, is at least a large exaggeration.
2. “The reason that the Earth is warm enough to sustain life is because of greenhouse gases in the atmosphere”.
And at this point, there is a substitution of concepts. In the previous statement we talked about the atmosphere in general, and here about "greenhouse gases." In the logical chain, the main link lacks - evidence that the capacity of the atmosphere to absorb heat is determined only by greenhouse gases.Moderator Response:[DB] Shortened and hyperlinked URL breaking page formatting
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Ari Jokimäki at 01:00 AM on 28 September 2018Retraction of Florides et al. (2013)
Retraction Watch also has a post on this:
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MA Rodger at 22:26 PM on 27 September 2018New study reconciles a dispute about how fast global warming will happen
nigelj @17,
You are correct about the +12ºC world being possible. Indeed, the graphic @6 shows RCP8.5 could reach such a level of warming (showing global temperature relative to 1986–2005 so add another +0.6ºC to make it relative to the 1800s).
But note this graph is not showing a follow-on from "a +3.4ºC warmer Earth" after 2100, and I say this not because RCP8.5 is a tad warmer in 2100. (The graphic is showing +3.7ºC or +4.3ºC above the 1800s.) The graphic shows +12ºC not because of follow-on but because RCP8.5 includes accelerating forcing through to 2100 when the forcing-deceleration begins. By 2150, the additional annual forcing is still up at the level we see today.
Of course, there are feedbacks not modelled in these GCM-generated projections which was perhaps the thrust of the speculation @1. Yet the assessment leading to the +12ºC, any study of what these feedbacks will bring; that remains unmentioned. (Indeed, so too does your "about 8 degrees before things stabilise.")I'm always happy to re-appraise both my understanding of stuff and my writing in comment threads. I'm happy to amend that understanding and set out corrects to my comments, although I would not rate the humble pie of admiting-error as a happy thing.
Doug_C @1 presents five paragraphs. I agree with the first and the last. Indeed I strongly advocate the message of the first but apparently for different reasons than those given by Doug_C, reasons he sets out in the middle three paragraphs.
The second paragraph @1 is just a question but does imply "a +3.4ºC warmer Earth" is where we are going. My response @6 only points to the basis of "a +3.4ºC warmer Earth" and how humanity can (& will) do better. Perhaps I can add strength to that referencing of the basis of "a +3.4ºC warmer Earth" by quoting from that source. "While the challenges are significant, limiting warming to below 1.5°C by the end of the century is still feasible from current emissions levels. However, with every decade lost, these challenges and costs rise and will, at some point, become insurmountable with warming locked in to 1.5 or 2°C and above."
My referencing @6 (I can but assume) led on to (1)@10 which is saying the issue is the present and that our future climate is being "locked in". Again the implication is that "a +3.4ºC warmer Earth" has been locked in. I rebut this idea forcefully @16. (There is also in (1)@10 an assessment of present AGW being "concerning" and "very disturbing" but, as I read (1)@10, this isn't the issue.)The third paragraph @1 says that "a +3.4ºC warmer Earth" will be bad (& I agree wholeheartedly) but that it could 'carry through' to a +12ºC world. So @6 I ask for the basis of this 'carry through' to a +12ºC world. Sadly, the response (2)@10 is vague, pointing just to "researchers like James Hansen" and "some of them." The response also talks of "much of the research" being "conservative" which is the sort of non-specif comment I truly hate. It gives license to ignore research and is thus anti-scientific. More usually the "conservative" label is attached to the IPCC assessment reports which again as a generalisation is anti-scientific.
But in all this the +12ºC world is evidently speculation. There is some room for doubt with the meaning of the +3.4ºC world although the implication (apparently strong implication) is that @1 it is being predicted as our future.The fourth paragraph is surely flat wrong, even with the "complex life" being undefined. Is it actually saying that a +12ºC world would see the extinction of all eucaryotes, all mushrooms plants & animals? Or just all multi-cellular organisms? The palaeoclimate has certainly seen life survive across a +6ºC world. The speed of AGW will be devastating for natural ecosystems but to suggest a +12ºC world would kill off all complex life is surely wrong. No pockets of survivable climate, anywhere? (And that is ignoring human ingenuity finding a way to survive in such a world.)
Saying that, there are analyses describing the danger of extinction, as seen in the five previous mass extinctions, comes not directly from a climate change caused by some catastrophy but from from the impacts of the resulting unleashed procaryotes, the bacteria.And so, have I earned a serving of humble pie? Even a small serving? I don't see it myself.
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mondosinistro at 14:06 PM on 27 September 2018It's methane
Perhaps someone here can help me to clear up some confusion about methane and the Arctic. No one seems to be asking the question I have.
OK, I got the memo: I'm supposed to be freaked out because arctic thawing is going to release methane from the clathrates on the continental shelf. A little red meat for you: Shahkova, Wadhams, Beckwith, others. They're the ones that seem to be screaming the loudest about this.
Let's not get into the deep clathrates, or the land permafrost, as those releases are going to be pretty slow anyway. I'll stick to the clathrates on the Arctic Ocean continental shelf, which are shallow enough to be released quickly. Supposedly.
The problem I have with all this talk is simple. The claim is that the global warming we're going to have (depending on whom you ask, either by 2100, or sooner, or even already) is going to cause a catastrophic release of methane from clathrates at shallow depths, where it can warm more quickly because it's really cold at those high latitudes. And we're told that this amounts to hundreds of billions of tonnes of carbon.
Well, it's also well known that the Earth's gas, oil, and coal was laid down over the last 500 million years or so; more at some intervals than others, but overall, over hundreds of millions of years. Now, during the last 400 to 500 million years, the Earth has often been warmer than now, by several degrees C. In fact, the Earth has been in this "hothouse" condition for most of that time.
Then, if it's true that a warming of a couple of degrees C, or even say 6 degrees, is enough to release a big part of this stored gas catsatrophically, within a few decades (some, apparently, think within a matter of years), then how is it that there is even any methane left at all? It should have all been released long ago. In particular, that especially nasty time, about 250 million years ago, when all that H2S came out of the stinking ocean, should have eliminated all of the clathrates at that time.
Sure, some clathrates could have formed later, but if so, how could those amount to more than all the coal and oil, as some are saying?
For me, this doesn't add up at all.
Moderator Response:[DB] You seem to be exposed to misinformation. Please read this post on methane clathrates and put any relevant comments on the subject there, not here.
"Shahkova, Wadhams, Beckwith, others"
Claims made in the media are basically irrelevant. Science is not an agenda to be prosecuted in the media.
Lastly, this is an evidence- and science-based venue. The burden is on the user (you) to support contentions and claims with citations to credible sources. Preferably when you make them or, at the bare minimum, when asked. Please read the Comments Policy and ensure that all comments comply with it. Thanks!
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nigelj at 06:14 AM on 27 September 2018New study reconciles a dispute about how fast global warming will happen
MAR @16, I wonder if you are misinterpreting some of the comments posted by DougC. While he suggested various possible extreme scenarios, I did not see him suggesting such things are locked in already, and that we shouldnt or can't do anything to stop global warming.
And his suggestion that 12 degrees was possible may not be far from the truth. According to the research quoted in this article, burning all fossil fuels on the planet could cause warming approaching that level to quote "Global average temperatures would soar by 10C (50F), while the arctic, where temperatures in February year were already 16C above average, could see temperatures soar by 20C, researchers found." Of course this would require literally burning all the oil and coal on the planet, and would take several centuries and hopefully humanity isn't that stupid.
Even if we dont burn all fossil fuels on the planet, feedbacks could push warming to about 8 degrees before things stabilise.
Having said all that, your technical commentary on warming, Hansens views, etc looks entirely accurate and interesting to me, as are your comments on feedbacks, black carbon and sea level at RC. I certainly would agree we are still in a position to greatly improve outcomes, by appropriate emissions cuts and so on.
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John ONeill at 20:31 PM on 26 September 20182018 SkS Weekly Climate Change & Global Warming News Roundup #38
North Carolina gets nearly eight times as much power from nuclear as from solar, and that was completely undamaged by the hurricane. ( It was shut down ahead of time as a precaution, as is standard practice.)
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MA Rodger at 19:17 PM on 26 September 2018New study reconciles a dispute about how fast global warming will happen
Doug_C @7,
I have to contradict you and pretty-much refute everything you say.Homing in on two parts of your reply:-
♦ It is indeed a future you discuss, not the present. What did James Hansen say to the media just a few months ago? “It’s not too late,” Hansen stressed. “There is a rate of reduction that’s feasible to stay well below 2C. But you just need that price on carbon.”
Sorry! Correction. Hansen didn't 'say' it, he 'stressed' it!
♦ Climate forcing is not "locked in" and as a result the global warming is also not "locked in."
To be more precise, the majority of today's climate forcing is not locked.
Consider this. If we stop emitting today, the oceans will continue to absorb our CO2 as there will be waters that have not seen the light of day for centuries continuing to return to the surface and absorb CO2. After 100 years of zero net emissions, today's 410ppm CO2 levels would be down to something like 370ppm and in 1,000 years would be down to something like 355ppm. (And there it would remain for many thousands of years as the oceans would have then come into CO2 equilibrium and we would be reliant on geological processes for any further natural reductions.) This is why RCP2.6 is projected to result in peak temperatures by mid-century which coincidental with the climate forcing peaking.
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Doug_C at 07:02 AM on 26 September 2018New study reconciles a dispute about how fast global warming will happen
Here's bit on the isotopic evidence of the role than methane clathrates can play in this kind of scenario, the risk is very real.
Carbon isotopic evidence for terminal-Permian methane outbursts
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Doug_C at 06:58 AM on 26 September 2018New study reconciles a dispute about how fast global warming will happen
william @11
There are many unknowns with the methane clathrate gun hypothesis, one thing we don't want to find out is we got it wrong in predicting when it goes off and how much methane is released.
Billions of tons of methane being added in pulses to the atmosphere is a nightmare forcing we really don't want to see.
And it's hard to see how some of these deposits are going to remain stable as the temperature continues to climb in critical locations like the Arctic. It has happened before.
Ancient methane 'burp' points to climate change 110 million years ago
"The thawing of the so-called methane hydrates coincides with a period of warming following a volcanic eruption, which released a cloud of carbon dioxide into the atmosphere.
"That was when Earth transitioned from a cold climate to a warm climate," Grasby said.
"So we see this sudden and short term release of methane is coincident with this period of global climate warming.""
There's some question about how much of this methane would get into the atmosphere, but there is also isotopic evidence that methane pulses have played a significant role in previous rapid warming periods that have resulted in extinction level events like the End Permian.
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nigelj at 06:46 AM on 26 September 2018New study reconciles a dispute about how fast global warming will happen
DougC @10
"I'm going by what researchers like James Hansen have to say and acknowledging that much of research is conservative when compared to what we are actually seeing in a real world response."
The following article called "what lies beneath, the understatement of existential climate risk" may be of interest.
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John Hartz at 06:19 AM on 26 September 2018Climate scientists are in it for the money
Recommended supplemental reading:
Climate change science comeback strategies: 'In it for the money' by Karin Kirk, Yale Climate Communications, Sep 5, 2018
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nigelj at 06:15 AM on 26 September 2018New study reconciles a dispute about how fast global warming will happen
MAR @7, thank's, but it wasn't that research. I remember now it was this article on page 22 as follows:
Fasullo and Trenberth found that the climate models that
most accurately capture observed relative humidity
in the tropics and subtropics and associated clouds
were among those with a higher sensitivity of
around 4°C. 64 Sherwood et al. also found a
sensitivity figure of greater than 3°C.65 Zhai et al.
found that climate models that are consistent with
the observed seasonal variation of low-altitude
marine clouds have an average sensitivity of
3.9°C. 66 Recently it has been demonstrated the
models that best capture current conditions have
a mean value of 3.7°C compared to 3.1°C by the
raw model projections.67 -
william5331 at 05:43 AM on 26 September 2018New study reconciles a dispute about how fast global warming will happen
A most interesting analysis but possibly of acedemic interest. If we trigger a tipping point, all bets are off. The one we seem to be most worried about at present is starting to release the huge reserves of methane locked in clathrates. Indeed, this seems to be under way in the Arctic both on land and sea bottom. At some point this is likely to become self perpetuating and some research suggests that such an event in the past led to sudden and extreme changes in the climate. It has now been 55m years since the PETM so lots of time for clathrates to have accumulated. Since there seems no reasonable chance that we will significantly reduce our carbon output any time soon, we are pushing this experiment to the limit.
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Doug_C at 05:39 AM on 26 September 2018New study reconciles a dispute about how fast global warming will happen
MA Rodger @6
1. I'm not looking at a bleak future, I'm looking at a very disturbing present, catastrophic climate change isn't soemthing that is going to hit at some undefined point in the distant future it is here now. What does an almost complete loss of coral reef systems alone mean to an overall ecological integrity, something that is almost inevitable now with the decades of warming already locked in with the CO2 we've already emitted. Every extra year of emissions is locking in futher warming years down the road. I'm very concerned about what is already happening with a full expectation it will get much worse even if we fundamentally changed course today which we have not.
2. I'm going by what researchers like James Hansen have to say and acknowledging that much of research is conservative when compared to what we are actually seeing in a real world response. Whether it is ice loss, changing climate patterns and more. And some of them have made it clear they expect far more warming than the current predictions are estimating.
3. As long as we are emitting billions of tons of CO2 a year the positive forcing will continue, some nations like the one I live in are still projecting decades of large scale fossil fuel use. The Canadian federal government just spent $4.5 billion dollars to buy a dilbit pipeline to enable a tripling of capacity of this one line of one of the most carbon intensive fossil fuels there is, oil sands bitumen. There is not going to be any leveling off of the radiative forcing of CO2 as long as we are rapidly increasing atmospheric levels of CO2 by burning fuels like oil sands bitumen. And the lag in ocean warming means that the CO2 we emit today is not going to be rebalanced for decades.
4. It's not sea level rise that is going to set a long term limit on human forved climate change, it is going to be a thermal equilibrium in the oceans that will take centuries to establish based on the radiative forcing we have already created. The oceans are the main driver for climate and the main mechanism to move heat around the planet. This means there will be no such thing as stable weather and climatic conditions until this adjustment is completed. That alone is going to be a major stressor on people and entire biotas for those centuries.
We are messing with one of the fundamental factors that makes life possible on Earth in a way that assumes we are in control of this incedibly powerful mechanism.
I see no signs at all we are, the only choice we have now is how far we are willing to push it to cross tipping points some of which we almost certainly have not been able to define in any meaningful way yet.
It's Russian Roulette on a planetary scale, so yes, I am very concerned.
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SteveS at 01:50 AM on 26 September 2018Volcanoes emit more CO2 than humans
Umm, 18,000 tons * 365 days is 6.6 million tons, not billion. You're off by a factor of 1000. So Katla gives off ~0.02% of what humans do.
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Teddz at 01:18 AM on 26 September 2018Volcanoes emit more CO2 than humans
It's suggested here that man's contribution is about 30bn tons of CO2 annually. The Climate.gov website estimates it at 40bn tons.
The Katla volcano is currently out gassing at a rate of between 12 and 24 ktn a day. That equates to a mid range (18ktn) figure of 6.5bn tons a year. That's about 17% of what man's contributing.
It should get quite warm next year?
Moderator Response:[DB] As has already been noted, your statements and maths are erroneous.
Per NOAA, and Burton et al 2013 (which subsumes the works of Gerlach 2011), human activities produce more than 60 times the amount of CO2 than do all the volcanoes in the world, combined.
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One Planet Only Forever at 00:23 AM on 26 September 2018New study reconciles a dispute about how fast global warming will happen
SirCharles,
It is undeniable that non-profitable removal of CO2 from the atmosphere, starting now, will be required to limit the harm done to the future of humanity.
The more important understanding is that minimizing the harm done to the future of humanity by the 'people pursuing the Best Possible Present for Themselves any way they can get away with' will require a significant correction of the incorrectly developed socioeconomic-political games that people play.
If the systems are not corrected the developed results will be more harmful to the future of humanity, and in many more ways that the impacts of the production of excess CO2 from the burning up of non-renewable buried ancient hydrocarbons.
A caring and considerate portion of the population will not be able to overcome the damage done by 'those who care less and can get a competitive advantage in the competitions to appear to be superior relative to others by behaving less responsibly (more harmfully)'.
The systems need to change in ways that ensure that 'improved awareness and understanding of what is going on and the application of that knowledge to develop a sustainable and improving future for humanity' Governs the actions of everyone (the key part of the word Government).
And the thing that pursuers of personal liberty and smaller government appear to deliberately fail to understand is that 'the more people who self-govern more altruistically, the smaller the Government (the collective actions to limit the people who do not responsibly self-govern) will need to be'. And that increased proportion of altruistic power and wealth has to happen first - only then can Government get smaller. And until that imrpoved behaviour occurs in the general population and business world, the Government (of the people, by the people, for the people) must be ruled by caring, considerate, thoughtful altruistic people responsibly limiting what is gotten away with in the games people play.
Right now many of the supposedly most advanced nations are struggling to have the type of leadership that the future of humanity clearly requires. Some of the less developed nations appear to be getting more responsible leadership.
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SirCharles at 23:29 PM on 25 September 2018New study reconciles a dispute about how fast global warming will happen
2°C are almost impossible as temps have already risen by 1.2 degrees at 405 ppm CO2.
Moderator Response:[DB] Shortened image width to 450, as it was breaking page formatting. Please be mindful of this in the future.
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MA Rodger at 20:27 PM on 25 September 2018New study reconciles a dispute about how fast global warming will happen
nigelj @2,
The paper you perhaps recall saying that the models best at reproducing the climate have higher climate sensitivity due to clouds was likely Brown & Caldeira (2017) which I've not seen in full but lead-author Patrick Brown has a useful post on his website about it. -
MA Rodger at 20:25 PM on 25 September 2018New study reconciles a dispute about how fast global warming will happen
Doug_C @1,
The bleak future you paint for AGW is not one I see.
♦ Firstly, "a +3.4ºC warmer Earth" mentioned in the OP says its based on this which is the projected warming if we restrict our mitigation to 'current policies'. As the world ramps up its mitigation, that projected value will drop.
♦ Secondly, you do not set out the "current understanding" which you say demonstrates a possible +12ºC world. I am not aware of research that shows such warming (without unmitigated emissions continuing). Mind, I would add that there is much research to suggest that "a +3.4ºC warmer Earth" would come with added bonus warming from natural feedbacks which science cannot/doesn't yet quantify and even if there were no added bonus warming, "a +3.4ºC warmer Earth" is still not a good place to be.
♦ Thirdly, when it comes to that "stable balance" in global temperatures at the end of the AGW process, the forcing from CO2 & other GHGs will be in decline well before we reach the equilibrium temperature of our peak forcing. Indeed, with zero emissions the forcing level will be dropping fast enough to pretty-much cancel-out temperature rise. (Note, we will still be left with half our CO2 and thus more than half our CO2-forcing at the end of the coming millenium unless future generations act the reduce it further.)
♦ Fourthly, it is probably the sea-level rise that sets a limit for long-term AGW. I am always a bit pigged-off by SLR being only projected to 2100 rather than shown on a multi-century basis. IPCC AR5 SPM E.6 doesn't once countenance the problems of SLR post-2100. You have to dig a lot deeper to see what lies in store. You find Fig IPCC AR5 Fig 13.14 (pasted below) showing that even a +1.0ºC warmer Earth will experience multi-metre SLR which our decendants may prefer not to experience. (In 13.14, the left-hand graphics are 'multi-millenual', the right-hand SLR after 2000 years, respectively for thermal expansion, glaciers, Greenland, Antarctica, total.) And note the 7-metre rise caused by Greenland going into melt-down in a +1.5ºC world, a process which will become irreversible if it gets the chance. AR5 rather plays down the chances of any surprises from Antarctica in a sub+4.0ºC world but the message from Greenland is shocking enough.
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nigelj at 14:35 PM on 25 September 2018New study reconciles a dispute about how fast global warming will happen
I agree volcanic activity is clearly not responsible for the modern global warming period. It could only be implicated in the recent global warming period if there was some substantial change in volcanic activity in recent decades compared to earlier decades. Given the quantities of CO2 emitted by volcanoes are quite small compared to human emissions, according to sources mentioned above, there would need to be a very substantial and obvious change.
A quick look at "list of large volcanic eruptions of the 20th century" on wikipedia shows no obvious change in activity between the early part of the 20th century, and the part after 1975 when the "modern" warming period related strongly to CO2 emissions started. Ditto theres no difference in volcanic activity overall between the 19th and 20th centuries. Yes its eyeballing a list but that is sufficient in this case.
This is reasonably basic detective work, so the fact that the "denialists" don't register it looks like wilful ignorance to me in many cases. Head in the sand stuff. I'm so sick and tired of it. We should be able to have grown up conversation with this obvious material on the table, and not disputed and ignored. I'm all for genuine scepticism if its intelligent and evidence based, but I haven't seen any for years now.
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One Planet Only Forever at 08:38 AM on 25 September 2018New study reconciles a dispute about how fast global warming will happen
The aspirational objective of only 1.5 C warming is a key point of the Paris Agreement.
Leaving CO2 at the level that results in 2 C warming is unacceptable. And the lack of responsible leadership means that it is highly likely that non-profitable actions to sustainably remove CO2 from the atmosphere will be required (more if the impacts exceed the 2 C limit.
Since it is already unfair to impose the challenges of climate change on future generations (even unfair to impose 1.5 C impact), the current generation should be obliged to start un-profitably removing CO2 from the atmosphere, and back-tax the people who got wealthy undeservingly as much as possible to pay for what undeniably needs to start to be done.
It needs to be clear that wealth will be removed from people who benefit from the burning of fossil fuels to correct the harm done. That way the entire issue is in 'Their' hands. They want more wealth from the production of more excess CO2? They can only have what is left after paying to remove excess CO2.
Making the people who benefit from a harmful activity understand that they will be the ones to pay to fully neutralize the impacts of their pursuits, pro-rated by how much benefit they personally get, appears to be the only way those people will 'get the message'.
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Doug_C at 08:31 AM on 25 September 2018New study reconciles a dispute about how fast global warming will happen
The simple fact is we are emitting massive amounts of the primary persistent greenhouse gas into the atmosphere every year and some are still trying to find ever more convoluted ways to justify this.
Are Volcanoes or Humans Harder on the Atmosphere?
"This argument that human-caused carbon emissions are merely a drop in the bucket compared to greenhouse gases generated by volcanoes has been making its way around the rumor mill for years. And while it may sound plausible, the science just doesn’t back it up.
According to the U.S. Geological Survey (USGS), the world’s volcanoes, both on land and undersea, generate about 200 million tons of carbon dioxide (CO2) annually, while our automotive and industrial activities cause some 24 billion tons of CO2 emissions every year worldwide. Despite the arguments to the contrary, the facts speak for themselves: Greenhouse gas emissions from volcanoes comprise less than one percent of those generated by today’s human endeavors."
If there was a supervolcano or a massive flood basalt somewhere on the Earth's surface would we be debating at all the catastrophic impacts of it emitting 100 times the average amount of CO2 from tectonic activity every year.
We'd be preparing for the same kind of massive die-offs that the geological record indictates are associated with similar events like this in the past.
Something we are already beginning to see on a large scale when you consider the massive and rapid die-offs on the Great Barrier Reef alone.
This is a supervolcano we can shut of and in fact be much better for in terms of air quality, ecological integrity and financial cost.
The Data Says Climate Change Could Cost Investors Trillions
"If we stay on the current emissions path, the study predicts, the value at risk in global portfolios could range from about $2 trillion to $25 trillion. In a bit of understatement, Simon Dietz of the London School of Economics, the lead author of the report, told The Guardian, “long-term investors…would be better off in a low-carbon world.”
Estimates of climate risk in the trillions are unfortunately getting more common. Last year, Citi produced a powerful study of the costs and benefits of shifting the energy system toward low-carbon technologies. Unchecked climate change, Citi said, could cost the world $72 trillion by the middle of the century. But the big surprise in Citi’s report was the cost of building the low-carbon economy: the world can spend $2 trillion less in total on energy infrastructure and ongoing fuel costs than it would in the business-as-usual scenario. So we save $2 trillion and avoid losing up to $72 trillion in economic activity."
Fossil fuels are a lose-lose no matter how contrarians still try and load the dice in the favour of the fossil fuel sector by consistently downplaying the likely impacts of the continued emissions of tens of billions of tons of CO2 a year.
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nigelj at 06:56 AM on 25 September 2018New study reconciles a dispute about how fast global warming will happen
I was thinking something similar to Doug C. We think in terms of warming projections by the year 2100, but its rather an arbitrary date related to our own lifetimes. This is natural of course, but I think its the next 1 - 5 centuries that are crucial for humanity as a whole if one thinks in a futurist sense. Firstly its this period of about 1- 5 centuries where the full results of climate sensitivity (and climate tipping points) will be felt with sea level rise and full development of temperatures and their various consequences.
Secondly the planet is going through a population demographic transition where the most likely track will be the current 7.6 billion people increasing to 11 billion by the year 2100, then population levelling off or possibly falling very slowly. (refer projections of population growth on wikipedia). The point is a huge population bulge of about 11 billion people from perhaps about 2100 - 2500 seems likely and will coincide with the unfolding of the worst climate impacts. Of course this is a trend based on family size, and climate change itself could well become so catastrophic that it forces population down through significantly increased mortality. Either way, its an existential threat.
I recall reading that climate models that have best predicted the trends with clouds have high climate sensitivity. Sorry tried to find the source article but couldn't.
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Doug_C at 03:11 AM on 25 September 2018New study reconciles a dispute about how fast global warming will happen
2100 isn't the endpoint, we need to be looking at where the Earth will enter into a stable balance again.
With the feedbacks that will almost certainly result from a +3.4 Celsius increase by 2100, how much warmer will the Earth become after that.
The inpacts of a +3.4 C warmer Earth will be catastrophic to most life here, what if that carries through to a +12 C Earth or worse which is also possible with our current understanding.
That will kill off all complex life on Earth taking us back to a time dominated by bacteria and viruses.
The contrarians are almost certainly the most inaccurate at predicting outcomes with climate change because they look at the data as something to contradict not genuinely analyze.
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BeezelyBillyBub at 23:19 PM on 24 September 20182018 SkS Weekly Climate Change & Global Warming Digest #38
2018 = 408 ppm @ 1.2° C = Dangerous Climate Change
2030 = 430 ppm @ 1.5° C = Disastrous Climate Change
2050 = 470 ppm @ 2.0° C = Catastrophic Climate Change
1.5° C = 50% less emissions in 10 years.
2.0° C = 100% less emissions in 20 years.
1.5° C - 2.0° C = Runaway climate change
100% private world carbon emissions dividends
Moderator Response:[JH] Source(s) please. Thank you.
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John Hartz at 23:09 PM on 24 September 2018Sea level rise is exaggerated
ChezProvence: Furthermore, the head-line and sub-headline of the SA article do not comport with the facts set forth in the first three paragraphs of the article:
California coastal cities should be prepared for the possibility that oceans will rise more than 10 feet by 2100 and submerge parts of beach towns, the state Coastal Commission warns in new draft guidance.
The powerful agency, which oversees most development along 1,100 miles of coast, will consider approving the guidance this fall. A staff report recommending the changes was released last week.
Earlier commission guidance put top sea-level rise at 6 feet by 2100. But according to the new report, there’s the “potential for rapid ice loss to result in an extreme scenario of 10.2 feet of sea level rise” by the end of the century.
As Yogi Berra was wont to say, "It ain't over until the fat lady sings!"
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John Hartz at 22:19 PM on 24 September 2018Sea level rise is exaggerated
ChezProvence: Thank you for providing the documentation per my request.
The headline of the Scientiic American article:
Prepare for 10 Feet of Sea Level Rise, California Commission Tells Coastal Cities
The sub-headline of the article qualifies the headline:
Though an extreme scenario, it should be factored in to coastal infrastructure planning, new guidance suggests
That is quite different than your statement:
California has accepted a new building code, expecting 10 feet by 2100.
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ChezProvence at 21:24 PM on 24 September 2018Sea level rise is exaggerated
Thanks for the Nerem reference. This may be a local politics thing ... In the draft report of the California Coastal Commission, they acknowledged the 800mm rise shown by, Nerem ... added their own sense, suggesting that the most likely will be 1.2 m, worst case 2 m ... and proposed regulation for 3 m. Starting point is fig 4 on page 46 of the w6g reference above.
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ChezProvence at 16:49 PM on 24 September 2018Sea level rise is exaggerated
prepare-for-10-feet-of-sea-level-rise-california-commission-tells-coastal-cities/
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One Planet Only Forever at 14:09 PM on 24 September 2018Shell and Exxon's secret 1980s climate change warnings
nigelj,
There are a variety of definitions of propaganda (and advertising). And propaganda does not have to be misleading or harmful.
My 1985 edition of The Concise Oxford Dictionary defies propaganda as: association or organized scheme for propagation of a doctrine or practice; or doctrines, information, etc., thus propagated.
Merriam-Webster On-Line Dictionary currently defines it as: the spreading of ideas, information, or rumor for the purpose of helping or injuring an institution, a cause, or a person; or ideas, facts, or allegations spread deliberately to further one's cause or to damage an opposing cause.
And if it is Capitalized it is: a congregation of the Roman curia having jurisdiction over missionary territories and related institutions
So, in the minds of many, propaganda has only negative connotations. But that is a recent development. And it is not a fair re-definition since propaganda can be helpful to the development of a sustainable better future for humanity, but such helpful propaganda from elected leaders can be easily attacked by simply unfairly declaring it to be propaganda.
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John Hartz at 09:23 AM on 24 September 2018Sea level rise is exaggerated
Chez Provence: You wrote:
California has accepted a new building code, expecting 10 feet by 2100.
Please document and link to the source of this claim.
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nigelj at 06:16 AM on 24 September 2018Shell and Exxon's secret 1980s climate change warnings
I also dislike misleading rhetoric intensely. It has always been a part of advertising and general debate, but it seems to have increased in volume in recent years, or maybe I'm just getting old and noticing it more or something. But perhaps the advent of talkback radio and then the internet has amplified it, given it a huge platform in both general discussion and debate, and in advertising and marketing. This has changed the landscape, and demands a response and better awareness of the problem.
I think misleading rhetoric is almost as bad as lying. Its a way people have developed to hide information that stops just short of lying, so they can't be accused of lying. Yet to me its just as unacceptable, assumimg its deliberate or cynical of course.
Propaganda is formally defined as political information that is often misleading or one sided. I dont think I could ever call propaganda acceptable, but I agee that advertising is not always a problem, its entirely dependent on how its structured. But then most countries have laws to deal with misleading advertising, and in fact I lodged a complaint once, and the advertisement was removed from television.
But we don't deal with misleading rhetoric in public discussion so well. I suppose free speech is paramount, but I can only hope for spreading better awareness of the nature and unacceptability of misleading rhetoric and shaming people into using more open and transparent debate.
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ChezProvence at 04:01 AM on 24 September 2018Sea level rise is exaggerated
I started at about post #7 with sea level rising at 2.46 mm per year. Eight years later, that may be 3 mm per year (3.46 +/- 0.4) or so ... so about 0.1 in per year ... less than a foot by 2100.
California has accepted a new building code, expecting 10 feet by 2100.
Does this make any sense? Should we all be investing in Dutch dike companies?
Moderator Response:[DB] And yet, per Nerem et al 2018:
"Global sea level rise is not cruising along at a steady 3 mm per year, it's accelerating a little every year, like a driver merging onto a highway, according to a powerful new assessment led by CIRES Fellow Steve Nerem. He and his colleagues harnessed 25 years of satellite data to calculate that the rate is increasing by about 0.08 mm/year every year—which could mean an annual rate of sea level rise of 10 mm/year, or even more, by 2100."
"This acceleration, driven mainly by accelerated melting in Greenland and Antarctica, has the potential to double the total sea level rise by 2100 as compared to projections that assume a constant rate—to more than 60 cm instead of about 30." said Nerem, who is also a professor of Aerospace Engineering Sciences at the University of Colorado Boulder. "And this is almost certainly a conservative estimate," he added. "Our extrapolation assumes that sea level continues to change in the future as it has over the last 25 years. Given the large changes we are seeing in the ice sheets today, that's not likely."
And:
"the observed acceleration will more than double the amount of sea-level rise by 2100 compared with the current rate of sea-level rise continuing unchanged. This projection of future sea-level rise is based only on the satellite-observed changes over the last 25 y, assuming that sea level changes similarly in the future. If sea level begins changing more rapidly, for example due to rapid changes in ice sheet dynamics, then this simple extrapolation will likely represent a conservative lower bound on future sea-level change."
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One Planet Only Forever at 02:09 AM on 24 September 2018Shell and Exxon's secret 1980s climate change warnings
John Hartz,
On further reflection I am addressing any marketing efforts.
Advertising and propagada actually have no clear definitions. They can be done to raise awareness or to fool people into wanting or believing something. They can be more understanding/fact-based or more emotional/desire appealing. They can be political or business related. Anyone can believe whatever they want the terms to mean (but Nasi use of the term propaganda definitely still taints perceptions of the term).
My focus is on distinguishing acceptable vs. unacceptable, based on a Governing Objective of improving awareness and understanding and applying that knowledge to develop a sustainable better future for huamnity. And I consider the Sustainable Development Goals and other UN agreements (like nuclear non-proliferation, and Human Rights) to be sub-objectives aligned with that Governing Objective.
It would probably be better to use a term like "promotion efforts" when identifying that the important distinction is how helpful they are, with an added understanding that less factual but helpful promotion efforts are not really OK either. The acceptability is a combination of helpfulness to the development of a sustainable better future for humanity and being based on the improved awareness and understanding that has developed (something sounding helpful but not properly based on the constantly improving awareness and understanding needs to be updated/corrected).
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One Planet Only Forever at 00:49 AM on 24 September 2018Shell and Exxon's secret 1980s climate change warnings
I would add that I am not really a fan of deliberately misleading messages as part of a government propaganda program, even if the result would be more helpful behaviour of the people influenced by the propaganda.
Early propagada campaigna against Pot in Canada are an example. Discouraging the use of Pot is helpful, especially dicouraging it among younger people, but the campaign was a dismal failure because it was so grossly inaccurate. The new Pot propaganda campaigns in Canada are entertaining appeals for people to not toke and drive, and avoid combining pot with tobacco because of the effects of combined use.
And propaganda is government marketing. Governments do not advertise.
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One Planet Only Forever at 00:41 AM on 24 September 2018Shell and Exxon's secret 1980s climate change warnings
My definition is the simple use of emotional appeal to popularize a message. And I admit the eveolved concept of the term has been severely tainted by the Nasi use of Propaganda.
So my distinction is that propaganda for harmful intent is unacceptable, especially if the emotional appeal is combined with a deliberately misleading message.
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John Hartz at 00:10 AM on 24 September 2018Shell and Exxon's secret 1980s climate change warnings
OPF #10: You wrote:
Advertising and propaganda are not a problem. The problem is people being harmfully misleading, especially with appeals built to trigger myopic worldview primal human selfish reactions to overwhelm reasonable thoughtful altruistic modern human consideration.
The second sentence could very well be construed as a description of the "propaganda" process. What is your working definition of "propaganda"?
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Doug_C at 16:30 PM on 23 September 2018Shell and Exxon's secret 1980s climate change warnings
DrivingBy @6
"Oil is produced because we demand it. Private oil companies exist only because of the world's voracious demand, and if they went 'Poof' tomorrow state owned entities would expand to replace them, albeit with higher overhead.
Most of the world refuses to allow their government to dictate how much energy they consume in the form of food, manufactured products, heated, cooled or humidity controlled homes and asphalt on their roads, and the freight network that hoves all that supports civilization. When we demand these things by buying them, we cause oil to be extracted, transported and refined."
Oil and all fossil fuels aren't being used on a massive level because the public keeps demanding it, they are still the main source of energy for two key reasons.
1. A decadal and massively funded campaign on the part of the fossil fuel sector to deny the inherent risks in using fossil fuels on a massive scale.
2. Huge amounts of money spent to lobby politicians by the fossil fuel sector.
Lets look at British Columbia alone where I am now.
$5.2 million in political donations and more than 22,000 lobbying contacts
In an 8 year period the oil and gas sector paid politicians in BC alone $5.2 million and lobbyed them 22,000 times that's an average of 14 times a day.
These are products that we know are highly dangerous to keep using at the current scale, the only reason we are still on a course to imminent disaster with fossil fuels is because we are being held there firmly by the fossil fuel sector itself which has effectively captured regulators like the Nation Energy Board of Canada.
The courts here have ruled that our national energy regulator is captured by the fossil fuel sector.
After Federal Court quashes Trans Mountain, Rachel Notley pulls out of national climate plan
The majority of people are not asking for disater, we have been removed from the decision making process by those with a fundamental conflict of interest.
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Doug_C at 16:11 PM on 23 September 2018Video: Textbook Trauma – The Emotional Cost of Climate Change
What's going on with climate change alone is like a diagnosis of a terminal illness... for everyone.
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One Planet Only Forever at 14:51 PM on 23 September 2018Shell and Exxon's secret 1980s climate change warnings
Advertising and propaganda are not a problem. The problem is people being harmfully misleading, especially with appeals built to trigger myopic worldview primal human selfish reactions to overwhelm reasonable thoughtful altruistic modern human consideration.
And the governing objectives of acceptable leadership action need to be understood to be the promotion of improved awareness and understanding of what is really going on (the latest climate science, or any other learning), and the application of that knowledge to improve and achieve the Sustainable Development Goals.
Without that improved awareness and understanding, a society or organization has no real future. And government advertising and propaganda should be legally required to promote that awareness and understanding - for the good of the future, because the free-market certainly cannot be expected to do it.
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scaddenp at 12:58 PM on 23 September 2018Shell and Exxon's secret 1980s climate change warnings
One obvious (for William) example would be the NZ Electoral Finance Act 2007 repealed after only two years with a vote 112/9. Nonetheless, NZ does make it more difficult for corporations to buy elections. You can tell if a democracy is in trouble if you have lobbyists talking directly to politicians (buying favours via campaign funding) instead of trying to influence the electorate.
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John Hartz at 10:55 AM on 22 September 2018California plans to show the world how to meet the Paris climate target
Suggested supplemental readings:
Spotted at the Climate Summit: Republican Mayors by Liz Enochs, City Lab, Sep 19, 2018
Climate Summit Highlights States’ Commitment to Combating Global Warming by Russell Fortmeyer, Architectural Record, Sep 20, 2018
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MA Rodger at 08:51 AM on 22 September 2018Jennifer Francis: How Climate and Ice Melt Intensify Hurricanes
nigelj @4,
The article you link-to is based on Steffen et al (2018) 'Trajectories of the Earth System in the Anthropocene' which, even with Schellnhuber as a co-author, doesn't provide a list of tipping points projected for +1.5-2.0ºC. The source of the Fyson & Rahmstorf quotes @1 appears to be this web page which does lists five tipping points, referencing a graphic presented within a YouTube video which is Fig 1 from Schellnhuber et al (2016) 'Why the right climate target was agreed in Paris'. This Fig 1 does show thirteen 'tipping points' (if you can call them that), of which five begin to 'tip' below 2.0ºC with one of them entirely 'tipping' below 2.0ºC.
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nigelj at 05:40 AM on 22 September 2018Jennifer Francis: How Climate and Ice Melt Intensify Hurricanes
Sauerj, the 13 climate tipping points are listed in this article on a useful map.
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John Hartz at 04:33 AM on 22 September 2018Jennifer Francis: How Climate and Ice Melt Intensify Hurricanes
Recommended supplemetal reading:
How Arctic warming could have steered Hurricane Florence towards the US, Guest Post by Jennifer Francis, Carbon Brief, Sep 17, 2018
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sauerj at 23:16 PM on 21 September 2018Jennifer Francis: How Climate and Ice Melt Intensify Hurricanes
BBB (@1): Interesting information. Could you reply w/ the list of 13 tipping points, and the 5 that will be tipped at 1.5-2.0C. I would like to see/know that list. Thanks!
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Lachlan at 16:03 PM on 21 September 2018Shell and Exxon's secret 1980s climate change warnings
William @5, the problem with making it illegal to fund any politician privately is that it entrenches the existing politicians. If nobody has any advertising funding except for the current politicians (or parties), then voting for anyone else would be playing roulette.
I agree that you have identified a big problem, but not with the solution. There is a saying "For every complex problem there is a simple solution, which doesn't work".
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