Climate Sensitivity Stunner: Last Time CO2 Levels Hit 400 Parts Per Million The Arctic Was 14°F Warmer!

We have pushed atmospheric CO2 levels to 400 parts per million (ppm) for the first time in human existence.

At the same time, a truly remarkably set of paleoclimate data shows the climate is much more sensitive to CO2 than we thought. And that means returning as quickly as possible back to 350 ppm is a vastly more rational course of action for a non-suicidal civilization, than, say continuing our unrestrained march toward 600 ppm, then 800, and then 1000.

NOAA reported Friday that the daily mean concentration of CO2 in the air around Mauna Loa, Hawaii, surpassed 400 parts per million this week:

At the same time, a major new Science study of paleoclimate temperatures — based on “the longest sediment core ever collected on land in the Arctic” — revealed what happened the last time we had similar CO2 levels:

“One of our major findings is that the Arctic was very warm in the Pliocene [~ 5.3 to 2.6 million years ago] when others have suggested atmospheric CO2 was very much like levels we see today. This could tell us where we are going in the near future. In other words, the Earth system response to small changes in carbon dioxide is bigger than suggested by earlier models,” the authors state.

Yes, contrary to one or two (misreported) models suggesting a climate sensitivity on the low side, this study joins the myriad analyses of data that find it is likely to prove on the high side. For instance, recent observations of relative humidity in the tropics and subtropics found that “Future warming likely to be on high side of climate projections,” according to a November paper in Science.

How sensitive is the climate to increases in CO2, according to this “absolutely new knowledge” of paleoclimate temperatures?

Another significant finding to emerge from this first continuous, high-resolution record of the Middle Pliocene is documentation of sustained warmth with summer temperatures of about 59 to 61 degrees F [15 to 16 degrees C], about 8 degrees C [14 F] warmer than today.

This period of Arctic warmth “coincides, in part with a long interval of 1.2 million years when the West Antarctic Ice sheet did not exist.” Indeed, sea levels during the mid-Pliocine were about 25 m [82 feet] higher than today!

It is worth noting that a 2009 analysis in Science found that when CO2 levels were this high 15 to 20 million years ago, it was 5° to 10°F warmer globally and seas were also 75 to 120 feet higher.

The risks of failing to sharply curtail carbon pollution are enormous if the climate sensitivity is on the low side (see “Memo To Media: ‘Climate Sensitivity’ Is NOT The Same As Projected Future Warming, World Faces 10°F Rise“). But the risks of inaction are beyond incalculable if climate sensitivity is in the middle end of the range, let alone the high end suggested by the paleoclimate data:

Science (1/11) study — On our current emissions path, CO2 levels in 2100 will hit levels last seen when the Earth was 29°F (16°C) hotter: Paleoclimate data suggests CO2 “may have at least twice the effect on global temperatures than currently projected by computer models”

As I explained in Nature online back in 2008 (here), once you factor in carbon-cycle feedbacks, even the uber-cautious Fourth Assessment report (AR4) of the IPCC makes clear we are headed toward 1000 ppm (the A1FI scenario). That conclusion has been supported by just about every major independent analysis, including a recent report by PricewaterhouseCoopers (see Study: We’re Headed To 11°F Warming And Even 7°F Requires “Nearly Quadrupling The Current Rate Of Decarbonisation“).

This new paper is just the latest to suggest the Arctic will warm much faster than the models have suggested. For instance, back in 2006, scientists analyzed deep marine sediments to understand the Paleocene Eocene thermal maximum, a brief period some 55 million years ago of “widespread, extreme climatic warming that was associated with massive atmospheric greenhouse gas input.” That Nature study (subs. req’d) found Arctic temperatures almost beyond imagination–above 23°C (74°F)–temperatures more than 18°F warmer than climate models had predicted when applied to this period. The three dozen authors conclude that existing climate models are missing crucial feedbacks that can significantly amplify polar warming.

Clearly our climate models don’t do a good job of explaining what’s happening in the Arctic right now:

Arctic sea ice is melting much, much faster than even the best climate models had projected (actual observations in red). The reason is most likely unmodeled amplifying feedbacks. The image (from Climate Crocks via Arctic Sea Ice Blog) comes from a 2007 GRL research paper by Stroeve et al.

And this underestimation of polar amplification in turn leads the authors of the new study — and many other scientists — to conclude that the climate’s overall sensitivity is on the high side. As the UK Guardian reports:

Prof Robert Spicer, at the Open University and not part of the new study, agreed: “This is another piece of evidence showing that climate models have a systematic problem with polar amplification,” ie the fact that global warming has its greatest effects at the poles. “This has enormous implications and suggests model are likely to underestimate the degree of future change.”

Given that the Arctic is already losing ice several decades faster than any major climate model had projected, we should expect that the permafrost — which contains twice as much carbon as the atmosphere currently does — will also go faster than the models suggest.

Indeed, a 2008 study by leading tundra experts found “Accelerated Arctic land warming and permafrost degradation during rapid sea ice loss.” The study’s ominous conclusion:

We find that simulated western Arctic land warming trends during rapid sea ice loss are 3.5 times greater than secular 21st century climate-change trends. The accelerated warming signal penetrates up to 1500 km inland….

This in turn suggests that the extra warming from the released permafrost carbon will be on the high side (see “Carbon Feedback From Thawing Permafrost Will Likely Add 0.4°F – 1.5°F To Total Global Warming By 2100“).

Anyone betting on a low sensitivity of the climate to carbon is literally betting against history.

Finally, this new analysis of Arctic sediments is a very impressive piece of work whose conclusions are hard to dismiss:

“It shows a huge warming – unprecedented in human history,” said Prof Scott Elias, at Royal Holloway University of London, and not involved in the work. “It is a frightening experiment we are conducting with our climate.”

The sediments have been slowly settling in Lake El’gygytgyn since it was formed 3.6m years ago, when a kilometre-wide meteorite blasted a crater 100km north of the Arctic circle. Unlike most places so far north, the region was never eroded by glaciers so a continuous record of the climate has lain undisturbed ever since. “It’s a phenomenal record,” said Prof Peter Sammonds, at University College London. “It is also an incredible achievement [the study’s work], given the remoteness of the lake.” Sixteen shipping containers of equipment had to be hauled 90km over snow by bulldozers from the nearest ice road, used by gold miners.

Previous research on land had revealed glimpses of the Arctic climate and ocean sediments had recorded the marine climate, but the disparate data are not consistent with one another. “Lake El’gygytgyn may be the only place in the world that has this incredible unbroken record of sediments going back millions of years,” said Elias. “When you have a very long record it is very different to argue with.”

If you want to learn more about this research, you can read the news release, the study itself (subs. req’d) or watch this video from the lead author, where you will also learn how to pronounce “El’gygytgyn”:

127 Responses to Climate Sensitivity Stunner: Last Time CO2 Levels Hit 400 Parts Per Million The Arctic Was 14°F Warmer!

  1. Superman1 says:

    With higher climate sensitivity, it will be even more difficult to stay within the temperature constraints of Anderson’s emissions trajectory. Since there is no way we can curtail the emissions sufficiently to stay under 1 C using present climate sensitivity assumptions and no feedback included, and since 1 C is probably a factor of two too high as a ceiling, there is certainly no way we can stay under the ceiling with these new findings.

  2. Superman1 says:

    In short, with these more severe climate sensitivity constraints, there is no way we can get there from here. The hole we have dug for ourselves is so deep, there is No Way Out!

  3. Ed Leaver says:

    Thanks Joe. One might note that continuous Arctic climate record from ~5 my ba to present is much more informative of our near future than the record 11 – 15 my ba. There appear to be four requirements for formation of polar ice sheets:
    1. A continuous land bridge between continents in northern and southern hemispheres.
    2. Goldilocks ocean circulation (Atlantic Conveyor not to fast nor too slow)
    3. GHG beneath about 300 ppm CO2e
    4. Alignment of the stars.
    These must all be met. The first has held for approximately the past 5 my as the Panama Isthmus closed the Central American Seaway at about that time. (References at Why Anthropogenic Global Warming.)

  4. prokaryotes says:

    There is yet another recent “unsettling” discovery…

    Patterns and mechanisms of early Pliocene warmth

    A huge pool of warm water that spanned the Tropics four million years ago suggests climate models might be too conservative in forecasting tropical changes. Dr Chris Brierley (UCL Geography), a co-author of the paper published in Nature, explains that this giant mass of water would have dramatically altered rainfall in the tropics. Its decay and the consequential drying of East Africa may have been a factor in Hominid evolution. With green house gases accelerating climate change, Dr Brierley says we cannot rule out such a future for the world with the return of uniformly warm seas in the Tropics.

    Has video too.

  5. Ken Barrows says:

    If the problem is getting worse and worse, how is the “technology is all we need” solution feasible?

    It’s not just about more renewables; it’s about fewer of just about everything.

  6. yphilj says:

    “It is worth noting that a 2009 analysis in Science found that when CO2 levels were this high 15 to 20 million years ago, it was 5° to 10°F warmer globally and seas were also 75 to 120 feet higher.” – We are thus committed to 3 degree Celsius warming already!?

  7. Thank you for this analysis, Joe. I am a home orchard enthusiast and a member of the California Rare Fruit Growers. I was disappointed this weekend to find other members of that organization referring me to the recent Harrison Schmidt OpEd in the WSJ as the leading view on CO2. My response was to refer them to UC Davis’s recent conference on “Climate-Smart Agriculture” and to suggest that they might have more credence than an OpEd in a Murdoch owned paper.

  8. Joe Romm says:

    i’ll do a short post on WSJ piece Monday, but I though this deserved priority since it is actual science.

  9. Superman1 says:

    “how is the “technology is all we need” solution feasible?”. It’s not; it never was. But, the real solution (which may no longer exist) of reducing demand harshly won’t ‘sell’, even to the supposed ‘climate hawks’ on this site, so we offer a non-starter to make it appear we are interested in ‘fighting’ climate change.

  10. Ed Leaver says:

    The above is a bit simplistic, and holds more for global ice ages (periods of continental glaciation) than just polar ice caps. The Antarctic cap formed under less stringent conditions about 35 mya with the opening of the Drake Passage and isolation of the Antarctic continent.

  11. prokaryotes says:

    Reminds me of this

    Al Gore wants to ‘awaken’ Rupert Murdoch on climate change

    This OpEd was probably Murdoch’s answer.

  12. fj says:

    More evidence of a crisis out-of-control requiring a crash effort to stop accelerating climate change.

    The message must be loud and clear; much louder than Keystone XL:

    We must zero out emissions at wartime speed.

  13. Carol says:

    Important piece—as always, thank you Joe.

    Today—being Mother’s day—-I had to ask myself what on earth I was hoping to find on this site (and why I would even go here today?!) But here I am and here is this dreadful, nightmarish (but not surprising) news.

    I’m not a big fan of Mother’s Day (most holidays for that matter) but today is especially challenging due to the fact that I am a mother of a fifteen year old. I brought her into an environmental mess!
    When I had my daughter in 1998 I was hopeful that we could turn things around —–even though James Hansen (and others well before him) had sounded the alarm back in 1988. And here we are at 400PPM. Wow.

    For the mothers out there who get the facts about climate change and are depressed (and sometimes downright terrified) because they understand what this means for their children(and themselves): anyone out there have anything positive you can pass along . . .. something that inspires hope and perseverance on this Mother’s Day?

    To all the mothers reading this blog—-love and peace to you.

    Joe—-grateful your Mom brought you into the world!

    To all the mothers who teach their children to love, respect and care for the earth—-thank you.

    And love to our scorched, battered, blighted Mother Earth, beautiful planet that she still is—-

    Happy Mother’ Day.

  14. BobbyL says:

    I think it is critical to know how long it took these changes to occur in the Arctic when 400 ppm was reached in terms of translating this information to action. If it took thousands of years then it will probably have little effect as a motivator but if it occurred much quicker then these new findings might help. So far we seem to be caught up in the dilemma that people are unlikely to make sacrifices if almost all the benefits will occur after their predicted lifespan. They feel they are here only once and want to make the most of it.

  15. prokaryotes says:

    The profound difference between the past and today’s emissions is the rate of it. The climate system response today will be therefore faster.

    There is a high likelihood for nonlinear behaviors (rapid developments), which can be observed today in relation to ice sheet and albedo dynamics.

    It happens today and people becoming more aware of it with each passing day. You can no longer pretend the opposite with a straight face.

  16. Mark E says:

    Superman, what do you hope to gain by posting here?

  17. prokaryotes says:

    “We changing the rate of emissions today 10.000 times faster then the natural system would have done…”

    When it took 1000 years in the past, this could mean today it happens within a century or even a decade.

  18. Superman1 says:

    What does anyone here hope to gain?

  19. catman306 says:

    We have reached 400 ppm, and it has warmed a bit (much more in the polar regions), but our weather is really being trashed by the’blocking highs’ that prevent the orderly movement of weather patterns across the planet.
    These blocking highs seem to be the genesis of ‘hell and high water’: more droughts and floods than in the past.

    Has anyone proposed doing some climate engineering and mitigation by breaking up these blocking highs? Couldn’t this be done by jet tanker flyovers spraying plain water into the stratosphere in the regions of the blocking high? The extra cloud cover generated up there might cool off the blocking high, causing it to dissipate and allow the jet stream to return to its former paths.


  20. Superman1 says:

    I’ll give you a more direct answer. I view this site as a forum for discussing climate change, especially for finding potential solutions. Suppose you had posted what I posted above. Assume one of two options: I agreed with it, or I disagreed with it.

  21. rollin says:

    Seeing the tremendous efforts being made to continue using any kind of fossil fuel vs. the efforts being made to use renewables does not bode well for future levels of CO2 and other greenhouse gases. We will be lucky to stop at 600 ppm, if it is possible to stop at that point.

  22. Superman1 says:

    If I agreed with your post, then I might ask: what would you suggest as a strategy for moving forward and coping with it? If I disagreed with your post, then I would state that I disagree, state specifically why I disagree, and possibly offer some solution out of the predicament. That is the kind of exchange I would expect from people who are seriously interested in looking for real solutions to the climate change problem.

  23. BobbyL says:

    I was thinking more along the lines if we somehow were able to keep the level around 400 ppm. I think it is clear to everyone who follows what is going on in climate science that if we keep on track to 1,000 by 2100 things will unfold much quicker than over millennia. But even on the track we are on the really super nasty stuff seems likely to occur toward the end of century barring a worst case scenario. I think this makes it difficult for people to relate it to their own lives.

  24. Rabid Doomsayer says:

    What we need to do to cope with what is ahead is similar to what we need to do to avoid the worst.

    As efficient as our modern civilization is, it is also the least resilient it has ever been. As change becomes increasingly inevitable, we are increasingly less able to deal with it.

    One hundred and fifty years ago, Every nation could have survived by itself if cut off from the rest of the word. Every community, apart from the biggest cities, was largely self sufficient.

    Now we are reliant on stuff that comes from around the nation and around the world. Some of our cities will be in crisis within days of a significant disruption. Our knowledge is held electronically reliant on numerous systems, all of which are vulnerable.

    Start by repairing the soil, so you can grow stuff.

  25. Rabid Doomsayer says:

    How much sulfer hexaflouide was there in the Pliocene?

  26. Superman1 says:

    “within days of a significant disruption”. Depends on what’s disrupted. In many cities, there are large concentrations of people who live in high-rises. They produce nothing locally, and depend completely on powered-elevators to get to their units. If power goes, they’re almost completely helpless. But, your observation is a good one.

  27. Superman1 says:

    There are three preceding posts in the CONTINUED series.

  28. Merrelyn Emery says:

    Yep, crash courses in gardening, productive soils and basic camp cooking, ME

  29. The only geoengineering idea that makes any sense at all is Alan Savory’s plan to revegetate deserts. That one’s a long shot at best, but at least it involves manageable scale and traditional agriculture. All the rest of them are hare-brained sci-fi stuff that will surely produce perverse, unintended consequences.

  30. Merrelyn Emery says:

    Bobby, people have already started noticing the nasty stuff that is occurring more frequently right now, ME

  31. Mulga Mumblebrain says:

    Fewer and less is required, and the rich, who consume most of the planet’s resources, must do the bulk of the ‘down-sizing’. To be done equitably and justly requires massive redistribution of the planet’s wealth, which is currently held in huge excess by the mostly hereditary global kleptocratic elite. As almost none of this wealth was ‘earned’ in the true sense, there ought not be any qualms over requiring its redistribution. 99% of the vast, larcenous, fortunes, serve no other purpose but egomaniacal display and a certain misanthropic urge, quite common on the Right, to deny others even a decent sufficiency of the good things of life. It makes the Right feel superior, their value system being entirely materialistic.

  32. Nell says:

    Roger that!

  33. Mulga Mumblebrain says:

    If sea-levels rise 120 feet, will the ‘Freedom Tower’ require a new spire, or will its new height of 1656 feet require that it be re-named the ‘New Amsterdam’ tower, or, perhaps, the ‘Petrus Stuyvesant’ Tower?

  34. Lou Grinzo says:

    It’s the gaps, stupid.

    For some time people have noted that we have a cognitive gap problem. Specifically, scientists know a lot more about our climate situation than do mainstream voters and consumers. This is the battle that consumes so many of us: Trying to educate people about the nasty realities of climate change in an effort to activate them.

    There’s also a second gap that doesn’t get as much attention, at least among climate communicators, and that’s the gaps between how the environment really works and what scientists, despite their tireless, and often heroic, efforts have figured out already. As scientists make these ongoing “it’s worse than we thought” discoveries, we continue to close this second gap, even as we realize that our prior mental models of environmental mechanisms were not just wrong, but typically far too optimistic. The caution on the part of scientists is normally a very good thing, of course, as we don’t want to leap to conclusions and constantly have to reverse course on what the science suggests public policies should be, for example. But given the hideously short time we have to deal with climate change and prevent consequences that read like a laughably bad science fiction story from the 1950’s, that delay is, to put it mildly, unfortunate.

  35. Mulga Mumblebrain says:

    Sounds like you have a few ‘rare fruits’ amongst your Rare Fruit Growers. Upon reflection, these fruits are, unfortunately, not so rare at all. Strange fruits might be better, swinging in the breeze.

  36. Mulga Mumblebrain says:

    How on earth do you ‘awaken’ the undead?

  37. Mulga Mumblebrain says:

    Bollocks! The ‘super-nasty stuff’ is happening already, and concentrating on 2100!!?? is, in my opinion, a form of soft denialism, procrastination that delivers a disaster beyond imagining to the children and the yet unborn.

  38. Dennis Tomlinson says:

    Not sure Rabid, but, as we dig ourselves deeper and deeper, we must be nearing a similar amount at present.

  39. h4x354x0r says:

    Given the choice between slow poisoning and immediate deprivation, humans choose the former far too often.

    Superman1 is right: sudden, significant conservation is one of the very, very few practical solutions we have at our disposal. Conservation is really the quickest, cheapest, lowest hanging fruit we’ve got right now to combat climate change. But, of course, it seems to be the one thing people aren’t willing to do.

    It really can be done, too. I’ve displaced over 150,000 car miles on a bicycle so far, and I’m still pedaling strong. That’s basically an entire car, all it’s fuel and oil and tires and maintenance, not burned up or used; an estimated 40 tons of carbon not emitted. Just one person.

    Everyone can do something. Cycling is a wonderful thing to do for reducing fossil fuel use. Avoiding beef is another one (very energy intensive, all fossil, to produce). Plus, there are lots of smaller things everyone can do to conserve energy.

    EVERYONE can do something, everyone should do something, everyone needs to do something!

  40. BobbyL says:

    I would would put the emphasis on energy efficiency, which actually the US has made great strides in, as has having the most potential for reducing emissions and people as well as governments and institutions are often very willing to take advantage of because it saves them money in the long run. However, it expensive. LED light bulbs are now available but they are costly, refitting a house for energy efficiency I think typically costs over ten thousand, electric cars and hybrids cost more than cars with regular internal combustion engines, energy efficient appliances cost more, etc. I would imagine we could easily reduce the energy we use by at least 30-50% and probably much more if the whole country adopted all the energy efficiency technology available but the obstacle remains initial cost.

  41. fj says:

    Amazing people still think climate change is the distant future.

    The President is not taking charge and is allowing these myths to continue.

    By 2020 the real battle for survival will have begun to reduce emissions as fast as possible and restore the environment we depend for existence.

  42. BobbyL says:

    I figure sea level will reach 120 feet in about 2 to 3 thousand years. I would assume that NYC would have been moved to what are now the hilly northern suburbs by then, out of harms way several hundred feet above sea level. I have no idea where they can move Miami. To another state I guess. Any suggestions?

  43. BobbyL says:

    Whatever nasty that is happening now in rich countries like the US is very manageable. We have gotten used to dealing with droughts, violent storms, floods, wildfires, etc over many decades. Of course part of the problem is people choosing to live next to the ocean, in river flood plains, in forests that burn, etc. These type of events in poor countries can be unmanageable as was the case with Hurricane Mitch which devastated parts of Central America. I don’t get the sense that Americans are particularly worried about the effects of climate change at present and really aren’t sure what are the effects and what aren’t. There is probably more confusion than concern.

  44. Merrelyn Emery says:

    Might be time to fly that Tardis back to Earth and have a look at the reality of melting ice sheets, ME

  45. prokaryotes says:

    Just by cutting all the subsidies to the “root of the problem” dirty oil/gas/coal + redirecting these to clean tech will free globally a number around 500 billion annually.

    “Where there’s a will there’s a way.”

  46. Dromicosuchus says:

    Dennis Tomlinson: I think Rabid Doomsayer’s point was that there was NO SF6 in the Pliocene; it’s an entirely artificial gas, with no known natural sources of any kind. Effectively every last molecule of it in our atmosphere was generated by human means.

    On another note…I find myself profoundly confused by the one of the papers referenced in this article (the Jeffrey Kiehl piece, also the subject of this previous post: and with this press release: Everything I’d previously read regarding temperatures over the last ~550 million years (and not just from that 1999 graph that’s used on Wikipedia; more recent research, as well) indicated a fairly small range of global temperatures, generally at most -2 K to +8 K of preindustrial temperatures. Certainly, I’ve never seen any global reconstructions before that produced something as absurdly high as +16 K 30 MYA. Heck, if that were actually the case, then the global average temperature at, say, ~100 MYA (based on this graph, at least: should have been about 45˚C–clearly impossible, since the extremes of temperature that implies would be lethal for almost all life on Earth.

    The +16 K (and for that matter, +8 K) figures seem to be fairly explicitly described as global average temperatures rather than polar temperatures (which would be far more plausible), but I have a lot of trouble believing that they’re accurate. Am I missing something?

  47. Merrelyn Emery says:

    The growing disaster bill is only manageable if you have a growing economy, dropping unemployment and increasingly productive people. Not looking good from that perspective, ME

  48. Merrelyn Emery says:

    Blaming the victims again, ME

  49. BobbyL says:

    The US economy has grown every quarter since 2009. Job growth is now enough to account for people entering the workforce but not enough to get the unemployment rate down. But we didn’t have any problem coming up with 60 billion for Sandy. I don’t think any other disaster has caused nearly that much damage since Katrina in 2005 which was the costliest natural disaster in our history. Parts of the Jersey shore are getting rebuilt (perhaps a stupid idea), wildfires are how the forest renew themselves, part of nature as it were. They are often worse than they would be because we try to prevent them and the stuff that burns accumulates. The Texas drought of 2011 cost the state billions but probably had little or no effect on food prices. The drought of 2012 in the Midwest didn’t appear to be a disaster in terms of food supply. The US seems to pick up the pieces and move along. I think we are still a long way from things being unmanageable. I think the sky will eventually fall but it hasn’t happened yet. Still not time for Chicken Little to do his thing.

  50. grant says:

    Given that we are NOT 14 degrees F. warmer, I would take that to suggest that there is NO correlation between CO2 level and temperature of any significance. Thus we until we do know what controls temperature changes, we should focus our efforts on mitigation of the current situations rather than chasing bogeymen. Start by moving people out of flood plains.

  51. Jack Burton says:

    Right now the Oceans are proving to be able to kick the can down the road. Sucking up most of the heat and also taking in much of the CO2 emissions. A thinking person would guess that the oceans can not continue to be the shock absorber much longer. The prospect for radical non linear behavior is becoming more real.
    On the subject of 2c and 2100. Ever notice how almost every story on climate somehow drags up the great 2c limit we can reach and all the real change happening in 2100. What is up with that? It is like people have lost the ability for independent thought. Someone threw those lines in the sand out there and even top level climate scientists parrot them endlessly. 2100? Get real, the arctic is in run-away melting NOW. Worse to come.

  52. Robert In New Orleans says:

    So when do we hit:

  53. Tom King says:

    Grant, if you’ve ever driven a car, you’ll know that pressing the gas doesn’t translate into instant speed just like pressing the brake doesn’t translate into instant stops.

    The bigger the car, the longer it takes for momentum to be added or subtracted. Now picture a car the size of the planet. The fact that we’ve been able to create such drastic changes so quickly bodes ill for future attempts to slow things down.

  54. Jacob says:


    I, for one, read everyone’s posts here. Clark’s posts are equally as relevant to me as all the other posts. None of us wins when we fight against each other, we’re all on the same side here.


  55. Jeff Poole says:

    I’d say destroying 80% of the ice cap and completely disrupting northern hemisphere agriculture count as super-nasty.

  56. Jeff Poole says:

    That’s what I’ve been doing with Jerry for the last decade. We were expecting/hoping that there’d be a crisis that would force our species into realising that sustainability isn’t an optional extra well before he runaway change started.

    All seems a bit pointless now that we’ve gone over the edge.

  57. Jacob says:

    “Given that we are NOT 14 degrees F. warmer, I would take that to suggest that there is NO correlation between CO2 level and temperature of any significance.”

    A pot of cold water doesn’t start boiling after a minute on a hot stove, Grant. It takes time to heat up. All we’ve done is turn the stove to high, and the water is slowly warming up.

    The Earth had been locked into a relatively stable climate state for millennia and we’ve just introduced this excess CO2 into the atmosphere in little over a century. It will take time for the total effects of our polluting transgressions to fully be felt. As it is we are starting to see these effects take place now. The climate changes slowly, that it is changing as fast as it is should be alarming to everyone.

  58. jyyh says:

    The video is great, and the study presented will likely be included to textbooks on climate, geology and paleontology pretty quickly. First ever connection between arctic temperatures and WAIS precence. Andrill and Lake El’gygytgyn records match.

  59. Mark E says:

    Superman’s posts make me less interested in reading for two reasons

    (A) There’s are so blessed many of them

    (B) Virtually all of them are tearing others down or simply saying its hopeless.

    When he starts offering constructive comments I will re-evaluate. As it is, in my opinion, he’s doing the Koch Brothers a service.

  60. Mulga Mumblebrain says:

    Are you sure of that?

  61. Mulga Mumblebrain says:

    Well said, pro, and that 500 billion could solve an awful lot of problems. Throw in another 500 billion by cutting totally wasteful military expenditures, and one trillion a year would go a long, long, way to saving our bacon.

  62. Mulga Mumblebrain says:

    Two to three thousand years!!?? You old ‘optimist’ you.

  63. Mulga Mumblebrain says:

    Don’t any of these ‘making the most of it’ people have any children?

  64. Mulga Mumblebrain says:

    It all depends on what sort of crowd you hang around with, and vague assertions that the public think such and such a way is, I would surmise, probably just psychological projection at work.

  65. Mulga Mumblebrain says:

    Ahhh-the simple-minded and their leaps of faith and outrageous assertions of absolute certainty. Where would humanity be without them?

  66. Mark E says:

    The jetstream certainly does seem to be involved in most of the current news making events. You’ve made an interesting idea, and yet every evaluation of a geoengineering idea should start with


    As dry as the highs are, I wonder how much water it would take to raise the humidity at 25000 feet enough to form lasting clouds? How many flights would that take? What’s the dissipation rate compared to the airlift cost? What’s the carbon footprint of lifting the water? Would you be making a longer-term warming for a short term effect?

    Similarly, without cloud formation, the water vapor becomes a non-reflective greenhouse gas so you could warm it further. If you do get clouds, we are still trying to figure out the net effect of clouds (warming or cooling overall and under what conditions?)

    In addition, these highs are one part of…. uh, is the term a “hadley cell”? Whatever…. if you tweak it over here, that does nothing to turn off the basic driving force behind the phenomena. So its going to keep going, probably. But in what new manifestation?

    Finally, suppose you do manage to lift enough water into the high to make a difference…. it certainly isn’t going to just stay there. Where else might the ice crystals end up and what else might it effect? If you take away rain from your neighbor, or are even perceived as having done so, are they going to start shooting?

    In my view, we should only try to mess with the blocking highs by aggressive mitigation of the cause.

    And we should really really teach ecology and systems-based thinking in school!

  67. Superman1 says:

    He made three points; to which one are you responding (or is your question relevant to all three)?

  68. Superman1 says:

    I offer the most constructive comments on this site. They identify the real problem that has to be solved, and the requirements that must be satisfied. Most others focus on peripheral targets, not the central problem. That’s not what I call constructive.

  69. Superman1 says:

    Obviously an optimist; you stopped at 600.

  70. Raul M. says:

    One of the new ways to instantly cool sheets of aluminum before it is rolled for further processing. Once wasted into the atmosphere it lasts way long and is way powerful in it’s warming ability.

  71. Joe Romm says:

    Not quite.

  72. Joe Romm says:

    We haven’t reached equilibrium with current CO2 levels. That will take some decades.

  73. Superman1 says:

    The two following requirements are necessary, but not sufficient, to keep us from going over the cliff: eliminate all non-essential fossil use missions (e.g., vacation travel), and make all essential fossil use missions much more efficient. Your proposal only addresses the latter. Given the new climate sensitivity data reported on CP yesterday, a critical situation has become even more critical; only the most ‘draconian sacrifices’ offer any hope (if there is any left) of a way out.

  74. Spike says:

    Interesting to see that in the study quoted precipitation was increased threefold with the warmer temperatures.

    Also in the news in the UK, more than half of common plants and one third of the animals could see a dramatic decline this century due to climate change – according to research from the University of East Anglia.

  75. Paul Klinkman says:

    Climatologists should look for two types of jobs:

    First, there will always be some work as an oil company flack. You have to prove that climate change doesn’t exist, but otherwise you get tenure, you get to hire grad students and all that.

    Second, there will always be some work for any climatologist who makes correct forecasts. You get the respect of your peers and that goes a long way toward getting tenure.

    In between are climatologists that hedge their bets halfway between the accurate people and the deniers. They’re the “consensus” people. They’re the worthless people that don’t take historical records of huge Arctic temperature swings (see the article above) into account. Trust me, nobody at all will give these people tenure. Don’t be one of them unless you like selling shoes for a living. Follow the science and be correct in your forecasts!

  76. Raul M. says:

    “Amazing people” still think climate change is in the near and distant future.
    The president deals with the myth that the president is immune from mutiny.
    By 2020 the practice of exclusionary principles will allow the concept of an Ark that only contains the means for the reseeding of life to the Earth.
    Just thinking of what is the best way to care for the least among us that could well transform to the future. For in the building blocks of life, what is most important and what could well evolve to the greatest extent? How could it given the reverse of evolutionary environmental conditions and the reestablishment of future conditions.?
    If the Venus syndrome isn’t predominate.

  77. BobbyL says:

    Don’t see any possibility of Draconian measures with so many democratic societies. We need solutions that aren’t Draconian. In most countries no one has the power to impose Draconian measures. North Korea is probably one place that could.

  78. Dennis Tomlinson says:

    Dromicosuchus: It’s in the eye of the beholder, perhaps beheld incorrectly. I took Rabid’s comment as a setup for a joke for which I was attempting the punch line – if only for the 40% share, should we be paid a team wage. Sorry for the confusion…

  79. Joan Savage says:

    Where the warm water was is a question.

    The formation of the Isthmus of Panama is thought to have affected the Atlantic current and led to formation of Arctic icecaps beginning about 3mybp (in the Pliocene), yet as early as 10 mybp (in the Miocene) North and South America may have gotten close enough to exchange plant material and could have begun altering ocean currents.

  80. Robert in New Orleans says:

    No, mankind stops for the most part at 600 ppm.

  81. Superman1 says:

    BobbyL, ‘Draconian sacrifices’ are a last resort, not a first resort. They are required when there are no alternatives left, and the choices are either survival or extinction. I believe we have run out of easy choices, and it is not even clear that draconian sacrifices will work at this point, but if there is the possibility of a chance for survival, they are what is required.

  82. Superman1 says:

    BobbyL, The possibility that climate sensitivities have been grossly underestimated, as implied by yesterday’s post, may mean that even ‘draconian sacrifices’ may no longer be sufficient to avert extinction, or at a minimum, that the most draconian of the ‘draconian sacrifices’ may be required. Think about the option space remaining with high climate sensitivities and the need to stay within the CO2 emission constraints to avoid exceeding the critical temperatures during the interim transition period.

  83. Superman1 says:

    What are your criteria for SUPER nasty (I like the prefix), and what are some examples of what you would consider SUPER nasty? Is it the old story of recession is when you are out of a job and depression is when I am out of a job?

  84. Superman1 says:

    “Trying to educate people about the nasty realities of climate change in an effort to activate them.” I’m not so sure how effective that link will be.

  85. Superman1 says:

    I know two types of people who are fairly well read about climate change. One type is the deniers, and they selectively quote from their extensive reading to support their pre-conceived agendas of natural variability. The other type recognizes the seriousness of what lies ahead, but they are resigned to its inevitability, believing they can have little impact on its outcome. I’m not sure of the best way to strengthen that linkage, or even if there is any way to strengthen that linkage.

  86. Superman1 says:

    Kevin Anderson dispelled the 2 C number as a purely political compromise, with no scientific basis. He states the community consensus is 1 C at best; my own view is that about 0.5 C, where the rapid melting of the Arctic ice became noticeable, would have been a much better target.

  87. Superman1 says:

    But, he does his computations, and proposes emissions constraints policy, based on 2 C (using models that do not include major feedbacks). Why? If he used 1 C, he would show we couldn’t get there from here (as he admits); the clock has run out! Add on feedbacks and the increased climate sensitivities posted on CP yesterday, and I don’t see any other conclusion than the clock has run out. Am I mistaken?

  88. Superman1 says:

    Good point!

  89. BobbyL says:

    I think it less of a question of whether Draconian measures can work than whether they can be imposed. If you are out there in our society you must know they are unacceptable, people are simply not that worried about climate change at this point. There is no hysteria out there. Far from it. They are shopping for SUVs.

  90. rollin says:

    Even with the newly formed Gulf Stream transporting moisture into the Arctic regions, the two major factors of ice formation were a declining atmospheric CO2 concentration and the effects of orbital eccentricities (milankovitch cycles). There are other factors of course, the formation of the Himalayas did reduce the albedo of the earth thus giving an edge to eventual glaciations.

    J Hansen has declared the glaciation cycle dead due to increased CO2 levels. It looks like the arctic ice formation will soon become a thing of the past.

  91. prokaryotes says:

    A bit drama can be good too. I do not agree with everything he says but if this is his way to express his views, so be it.

  92. M Tucker says:

    I think it is fascinating that this lake with its “longest sediment core ever collected on land” was found in Russia. It was Russian (Soviet) scientist Mikhail Budyko who first proposed in the 1970’s that a study be made of the Pliocene warming to get a better idea of what Earth could expect in the 21st century. He actually pioneered the study of climatology and is considered one of the founding scientists of physical climatology publishing “Heat Balance of the Earth’s Surface” in 1956. It is considered a very important book in the field of climatology.

    After the fall of the Soviet Union Dick Poore of the USGS and David Rind of NASA went to Russia and discovered Budyko’s work. In 1989 the USGS began to “develop a more quantitative data set for the Pliocene.” Thus began the USGS work on the mid-Pliocene warming, in concert with the NASA Goddard Institute, known as the PRISM (Pliocene Research Interpretation and Synoptic Mapping) project. To learn a little more about the project you could search USGS or NASA/GISS and you could read a very interesting article first published in American Scientist in the May-June 2011 issue. The author, Marci Robinson, suggested in that article that climate sensitivity may be higher than previously imagined: “Atmospheric carbon-dioxide concentrations during the Pliocene were only slightly higher than they are today. Still, global temperatures during the mid-Pliocene were on average 2 to 3 degrees warmer than today, and sea level was on average 25 meters higher. This apparent paradox—a warmer planet with comparable carbon dioxide levels—concerns some researchers who wonder whether even small increases in carbon dioxide can significantly alter our climate.”

    You can find the complete article in pdf form here:

  93. BobbyL says:

    To get to 120 feet you need considerable melting of the East Antarctica ice sheet. So far it is stable. Probably no one knows at what point it will start to melt.

  94. SecularAnimist says:

    Superman1 wrote: “eliminate all non-essential fossil use missions”

    And yet, your computer is still on.

  95. Gestur says:

    Respectfully, Lou—and I do mean with a lot of respect for you since you’ve easily garnered that from your many insightful comments here and elsewhere—I’m going to disagree with you that the problem of climate change inaction is critically an information deficit one. This whole area of why people aren’t acting to change their own life styles and why there isn’t more public agitation (i.e. beyond simple voiced support in surveys) to get meaningful changes in laws is fraught with identification problems for assessing causality. And I haven’t some clever econometric tool up my sleeve to help me sort out this causality knot. But this winter I’ve read and then thought a lot about a couple of books that more or less focus on this very issue and they’ve opened up a new way of thinking about this topic for me. [One by the English psychoanalyst Sally Weintrobe, “Engaging With Climate Change” and the second by the American sociologist Kari Norgaard, “Living in Denial”]. Using the psychoanalysts’ term for people who have knowledge about something but choose not to make use of it, disavowal, people in disavowal, and I think we’re talking about the majority of people in this country, know as much as they want to know, is how I would succinctly put it. And that’s not much, I grant you, as I’m sure many surveys would indicate is the case for this informational deficit. But that’s a long ways from establishing that this information deficit is causal as concerns climate inaction, etc. So I’d pose the question abstractly: why don’t people know more about CC?

    While I concede that it may have some causal role, my personal view these days is that this deficit of information is likely to be a relatively minor player. Mostly it’s a reflection of something else.

    Counterexamples are often useful and used in thinking about causality and for me it’s very insightful to consider how much people know—and have known historically—about how smoking tobacco induces lung cancer and CVD. And I mean the kind of technical knowledge that medical research professionals know: the theories of how it acts on cells in the lung and arteries. And I’d be surprised if many non-medical people know much about these technical matters, and yet we’ve managed to get population smoking rates down quite a bit from earlier periods. Lots of things to think about here vis-à-vis the situation with climate change, as many have done. But I’m interested just in this question of information or technical knowledge per se for changing behaviors. Of course we finally forced the tobacco companies to print warnings on their packages and a flurry of public health announcements came out warning people of the dangers of cigarette smoking, and of course we had the big court cases against the tobacco companies. All of this, and perhaps more, I’m sure had a significant impact on our population smoking rate. And you might choose to call this information, but it wasn’t the technical information about how tobacco actually brings about cancer and heart disease. Publicity yes, and dire warnings, that too.

    So I harbor some real doubts about how important the technical information deficit might prove to be in changing behaviors vis-à-vis climate change. Unfortunately, I think it’s a deeper, much more complex issue of what motivates us collectively and especially individually in the 21st Century—our basic psychological makeup—that has the larger causal role here.

  96. Spike says:

    More about the Pliocene comparison in the excellent article below.

    “Life abounded during the Pliocene. But such conditions mean agriculture would hardly be possible. The tropical Pliocene had intense alternating downpours and heat waves. Regular river flow and temperate Mediterranean-type climates which allow extensive farming could hardly exist under those conditions.”

  97. Superman1 says:

    BobbyL, “people are simply not that worried about climate change at this point.” That’s one of the reasons I posted what I did on #1 and #2 above. The gap between what we need to do and what we are doing is so large, I don’t see how it can be filled.

  98. Superman1 says:

    Given that we are holding steady for 5-6 C by the end of the century (if not sooner), you can forget about what will happen in 2-3,000 years. Nobody will be around to see it!

  99. Superman1 says:

    The educational issue is mainly a diversion. The electorate does not want to make the energy-intensive lifestyle sacrifices required to save the biosphere. This does not mesh with the political agenda of the activists, so they have created the strawman of deficient education.

  100. Superman1 says:

    You raise the smoking issue. In 2010, I heard the NYT tobacco expert summarize the smoking experience. It wasn’t the 1964 Surgeon General’s Report that made the difference; it had little impact. It was the financial penalties and mandates that the non-smoking majority imposed on the smoking minority that made the difference. That majority does not exist for climate change.

  101. Superman1 says:

    Even then, with all the hard smoking data available, the number of smokers only dropped in half, from ~42% to 21%. We don’t have the numbers for climate change, and the data, while very good, is somewhat softer than for smoking. The 2% who are willing to make the sacrifices necessary to save the biosphere will be carried over the cliff by the 98% who could care less!

  102. BobbyL says:

    I don’t think the choice is clearly between survival and extinction. In fact, it is unclear what the choice is. There seems to be a big grey area where things could go. This an issue that lacks clarity in all respects except that global warming is occurring and human sources are the main cause. Beyond that is speculation, some based on solid knowledge and some simply wild, particularly on the Internet.

  103. Merrelyn Emery says:

    If by edge you mean 400ppm, it’s a symbol and not really very different from 395. Whatever is coming, there will be survivors so I hope they have some of those skills, ME

  104. Superman1 says:

    Prokaryotes, What specifically do you disagree with in my statements in #1 and #2 above?

  105. Superman1 says:

    Obviously, there is much uncertainty about the eventual outcome. But, if one of the real possibilities, and in my view the most probably outcome, is extinction if we continue on our present course, then we should be planning to avert the worst possible case at all costs. Instead, we are doing nothing.

  106. Joan Savage says:

    I took the Brigham-Grette et al. paper to show that the 400+ ppm CO2/temperature shift/Arctic ice cap cycling occurred several times since the mid-Pliocene, and the shifts were relatively rapid, geologically speaking.

    So it might yet again, though not necessarily in human time-frames, which is usually Hansen’s point.

    We might have greater appreciation for the role of the Isthmus of Panama, as the canal bed elevation is about 100 ft above Pacific mean sea level, and therefore sea level rise in the next few hundred years could overtop the Isthmus.

    That would put us back in the Pliocene in yet another way, as it would create the possibility of a new version of Breierly’s big pool of warm water.

  107. Joan Savage says:


  108. Merrelyn Emery says:

    Sorry Bobby, East Antarctica has been losing ice since 2006 (NASA), ME

  109. BobbyL says:

    Going all out means tremendous disruption at all levels. I think the solution calls for addressing the problem while minimizing disruption. That is one reason why it so difficult to deal with. Nothing like solving the ozone hole problem. There very little disruption was involved and the problem could be dealt with. Here we have the opposite and it has us stymied.

  110. Jeff Poole says:

    No, that’s not what I meant.

    I meant the loss of the summer Ice Cap, the huge acceleration in warming due to the albedo flip – one summer = 20 years of human emissions according to Prof Peter Wadhams – and the exponential increase in methane emissions from tundra and shallow arctic clathrates.

    Even the next few years when we get a few days rising to a few weeks of ice-free arctic we’ll be seeing such a disruption to normal weather patterns that I expect some serious food shocks.

    Hungry people tend to revolt. And those revolutions aren’t going to aim toward sustainability or equity. Hungry people also tend to use whatever they can to grow or gather food so once the fighting starts I don’t expect much thought to be going into lowering emissions.

    Not that much thought has gone into that yet anyway…
    *wry grin*

  111. Colorado Bob says:

    JS –
    Thanks for the Panama comments. I had never considered the ocean claiming the Panama locks at sea level. The whole thing becomes worthless on that day .

  112. Colorado Bob says:

    yet as early as 10 mybp (in the Miocene) North and South America may have gotten close enough to exchange plant material and could have begun altering ocean currents.

    So, in a warm period with high sea level the land bridge arose. By 3 to 3.5 mybp it was complete. That left the Atlantic even less connected to the old ocean system.
    And the Earth began to cool.

  113. prokaryotes says:

    I would need you to be more concrete and link to facts which support your reasoning. Because sometimes you just state that the situation is hopeless, which is not constructive enough.

  114. wili says:

    And so is yours. And mine. (Though technically we get our electricity from wind here.) Your point?

    Should no one criticize any aspect of the world we live in until they have completely left that world?

    In my experience, any one making any kind of claim that something fundamental about society has to change is always accused by someone of either being:

    1) a hypocrite, or

    2)(if they have really tried hard to enact the change in their own behavior) of being “holier than thou.”

    And sometimes the same ad homs are hurled by the same people in the same sentence.

    Can we move past such puerile responses here at least. There is plenty enough that is more reasonable to question about Sup’s position without resorting to such childish taunts.

    What next? Are you going to tell the people here that are critical of capitalism to move to North Korea?

    I know you have many more worthy insight to contribute that this.

  115. Superman1 says:

    Prokaryotes, You posted the Anderson video that showed the near-impossibility of staying within the 2 C limit. Add to that his statement that 2 C is a political target that is too high by a factor of two, the fact that his computations do not include the feedbacks, and Sunday’s post that the climate sensitivity may be substantially larger than we have assumed, how would you come to any other conclusion?

  116. Superman1 says:

    Jacob, “we’re all on the same side here”. I agree with most of your points, but I’m not sure about the one I excerpted. My objective is to avoid climate catastrophe, making whatever sacrifices are necessary, using whatever approaches and forms of governance are required, voluntary or involuntary. I don’t see all those conditions reflected in most of the posts here.

  117. Superman1 says:

    We see comments that tend to end with: if we can make the transition without ‘draconian sacrifices’; if we can implement my technology first; if we can do it while maintaining democracy; if we can do it while maintaining prosperity. My view is: no conditions; whatever it takes!

  118. Superman1 says:

    Jeff, You have provided some good examples of why even the 1 C interim temperature ceiling constraint is far too high. The temperature at which the Arctic ice started to melt discernibly should have been the target, and even then, there should have been a built-in safety factor. The 2 C target is a fiction; how can we possibly get out of the hole we have dug for ourselves?

  119. Superman1 says:

    “addressing the problem while minimizing disruption.” When I look at the numbers incorporating the latest data, and look at the developments in the Arctic, it becomes crystal clear that ‘minimizing disruption’ coincides with ‘draconian sacrifices’!

  120. Joan Savage says:

    Correction- the graphs showed there were several Arctic warm periods and WAIS melts since the mid Pliocene, but the ‘last’ 400 ppm CO2 may need some clarification.

    In earlier research Pagani et al (2009) had concluded from other data that the Pliocene peak was between 365 and 415 ppm CO2.

  121. Artful Dodger says:

    Thank-you for taking the time to write, Carol. Happy Mother’s day to you!

  122. Jeff Poole says:

    Good question Mulga.

    I’ve frequently caused a shocked silence when I’ve asked the simple and obvious question…

    ‘How come a childless queer man (ie me!) cares more for your children than you do?’

    I’ve begun asking Green friends who have children if they think that having kids has made them unable to face the reality of the world they will grow up in.

    My social invitations are drying up faster than the Aral Sea!

    We are the prisoners of an evolved nature that discounts anything in the future compared to the here and now.

  123. Merrelyn Emery says:

    It’s not biological evolution Jeff. People today are expressing their purposefulness by defying the ‘authorities’ by engaging in maladaptive behaviours. Some of us have escaped and still try, as you do do, to make adaptive action, ME

  124. Solar Jim says:

    It’s the carbonic acid gas, stupid.

  125. Diego Matter says:

    Dear readers of Climate Progress

    Let me ask all of you:

    1. What is your annual electricity usage (write: kWh/year, number of people in household, all electric/electric and gas?

    2. Have you already switched to 100% green electricity from your utility?
    3. Have you installed solar PV to replace 100% of your annual usage?
    4. Have you had an energy audit at your home?
    5. Have you implemented the proposed changes?
    6. Do you use public transport all the time if possible and ride a bike?

    If you haven’t done 2. through 6., you shouldn’t give advice to others and start first with yourself!

  126. Joe Romm says:

    What advice to others is being given? We are all in this together, I’m afraid, so one person’s actions can’t solve the problem.

  127. Lou Grinzo says:

    Gestur (and everyone else here): I’ve posted some more thoughts on this on my blog (

    Feel free to stop by and join the discussion.