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Hansen throws cold water on cooling climate claim

By Joe Romm on March 3, 2008 at 8:45 pm

"Hansen throws cold water on cooling climate claim"

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NASA’s James Hansen has weighed in to

expose the recent nonsense that has appeared in the blogosphere, to the effect that recent cooling has wiped out global warming of the past century, and the Earth may be headed into an ice age. On the contrary, these misleaders have foolishly (or devilishly) fixated on a natural fluctuation that will soon disappear.

As Hansen explains:

Weather fluctuations or ‘noise’ have a noticeable effect even on monthly-mean global-mean temperature, especially in Northern Hemisphere winter. Weather has little effect on global-mean temperature averaged over several months or more. The primary cause of variations on time scales from a few months to a few years is ocean dynamics, especially the Southern Oscillation (El Nino — La Nina cycle), although an occasional large volcano can have a cooling effect that lasts a few years. The 10-11 year cycle of solar irradiance has a just barely detectable effect on global temperature, no more than about 0.1°C, much less noticeable than El Nino/La Nina fluctuations.

So what happened this winter?

The past year (2007) witnessed a transition from a weak El Nino to a strong La Nina (the latter is perhaps beginning to moderate already, as the ocean waters near Peru are beginning to warm). January 2007 was the warmest January in the period of instrumental data in the GISS analysis, while, as shown in Figure 1, October 2007 was # 5 warmest, November 2007 was #8 warmest, December 2007 was #8 warmest, and January 2008 was #40 warmest. Undoubtedly, the cooling trend through the year was due to the strengthening La Nina, and the unusual coolness in January was aided by a winter weather fluctuation.

Small long-term temperature changes have vastly more consequence than large short-term temperature changes:

The large short-term temperature fluctuations have no bearing on the global warming matter or the impacts of global warming…. A global warming much smaller than weather fluctuations has the potential for dramatic effects, e.g., by setting in motion future large sea level change, species extinction, and various other impacts.

His final point goes to the heart of a common misconception among many people:

Cold weather does raise an interesting point, though. People who do not like cold weather, and might have welcomed the idea that Minnesota may become more like Missouri or Massachusetts like Virginia, must give up that notion, unless they wish ill for a large fraction of the planet’s inhabitants, both human and other creatures. We are going to have to figure out a way to keep climate zones pretty much where they are now (winters will continue to happen, as always). It is possible that we can still do that — just barely. But I digress — that will be in our next paper, almost finished.

I’ll post that as soon as he does.

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28 Responses to Hansen throws cold water on cooling climate claim

  1. Beefeater says:

    We are going to have to figure out a way to keep climate zones pretty much where they are now (winters will continue to happen, as always). It is possible that we can still do that — just barely.

    Just how does he propose to keep climate zones static? When in the history of Earth has that ever occurred? Climate change means just that! Change, evolution, recede, retract, never static. Hansen has just made my point and blown his cover. Only a fool would believe that we can somehow “figure out a way to keep climate zones pretty much where they are now”.

  2. vg says:

    Just what if.. temperatures continue to decline? (for a very long time).

  3. John Mashey says:

    vg: let me rephrase your question to an equivalent:

    Just, what if … the First Law of Thermodynamics is repealed? And the Greenhouse Effect?
    Oh, bad question….

    When incoming energy is larger than outgoing energy, temperature rises.

    Due to increasing Greenhouse gasses like water vapor, CO2, CH4, etc, the temperature of the Earth *as a whole* is rising.

    So, why do we see such jiggles in the Earth’s surface temperature, which is what NASA GISS, Hadley, etc report? Why doesn’t the energy difference just show up smoohtly as CO2 goes up?

    A: most of the energy goes into the oceans, which have 1000X the heat capacity of the atmosphere. The ocean-atmosphere system has all sorts of jiggles that *move heat around*, but do not create or destroy energy.

    We care about surface temperature because we live here, and we have the longest temperature series, but the surface is a miniscule slice of the whole thing, and surface temperatures in any one place jiggle daily (day and night, far more than any long-term trend), yearly, and from decadal-scale oscillations. Likewise, the surface temperature as whole jiggles, from things like El Ninos that move energy from ocean to atmosphere, and La Ninas that do the reverse.

    Analogy:
    A bathtub is being filled [sun], slightly faster than it is being drained [heat radiation]. You have a bunch of floats, measuring the depth of the water. The depth would go up smoothly, except there’s a kid splashing around in the bath.

    Sometimes the kid lies back in the water, in which case the overall water level goes up [El Nino], but with waves, so that some floats go down.
    Sometimes the kid sits up, in which case the overall water level temporarily goes down [La Nina], but with waves, so a few of the floats go up.

    The kid splashes around the whole time, jiggling all floats second by second.

    At any point in time, there is a certain amount of water, but the average as measured by 1% of the floats is subject to lots of jiggles.

    Still, the water *is* going up, as long as more as coming in than draining out, and the physics of GHGs say that we’re slowly plugging the drain.

    See http://pubs.giss.nasa.gov/docs/2005/2005_Hansen_etal_1.pdf

    for a serious article on this, because guess what:

    The Earth as a whole is gaining energy, and all that some cold spell means is that some oscillation transfers energy from atmosphere/sea surface deeper into the ocean … but that energy doesn’t magically disappear, and the next time it comes back out…

  4. Andy Revkin says:

    Joe, does this now make you a media enabler, or simply a responsible communicator helping explain cold weather in a warming world to readers (through Dr. Hansen’s comments, which directly echo those in my Sunday story)?

  5. Joe says:

    Andy: I have long been a media enabler, since I routinely quote and link to you folks. But I think Hansen leads off with his strong views and he makes clear the weather hasn’t been unusually cold. Plus, of course, he is a primary source and doesn’t feel obliged to cite the disinformers.

  6. Bob says:

    John Mashey: the first law of thermodynamics gets you 1.5C warming, which is not likely to cause huge problems. The rest of the warming, the more dangerous stuff, is due to feedback mechanisms where the science is less settled.

    Regarding Hansen, he is of course correct that what we are now seeing is weather, and is not to be confused with the ongoing warming trend. If the PDO is flipping into a 30 year cold phase, however, we will see many more and intense La Ninas and a marked slowdown in the rate of warming that was observed from the late 70s to the late 90s.

  7. John Mashey says:

    Bob:

    The direct effects of increased GHGs clog the drain.
    The indirect (feedback) effects add more to the clogging, and while the uncertainty level of clouds is still more than we like, if the temperature goes up, at all, we’ll get more water vapor, and it’s pretty clear the ice-albedo feedback is going on. If there were a feedback like Lindzen’s IRIS hypothesis, then we’d have no worries, but that didn’t last very long.

    The PDO is an *internal* effect inside the Earth’s climate system. It moves energy around.

    So: the tub continues to fill, but the kid slowly sits up, which makes the measured level in the tub rise more slowly. Does that mean there is less total water in the tub? What happens when the kid lies back down? At the point, the measured levels hit new highs never seen before. For the Earth, regardless of what happens for surface temperatures during a 30-year cold phase, do you think there is less *total* energy at the end?

    What do you think the following warm-phase will look like? What do you think the El Ninos 30 years from now will look like?

    One more time: most of the heat capacity is *in* the ocean, not at the surface.

    All of this is why climate scientists think in decadal or multi-decadal terms, not this idiotic month-by-month thing.

    Anyway, please take a look at the paper I mentioned.

  8. Bob says:

    John M:

    I am familiar with the Hansen paper, and I am confused. Perhaps you can help. The upper layers of the ocean are heated entirely by solar radiation. The ocean is cooled by interactions with the atmosphere, among other mechanisms. Heat is transferred from the ocean to the atmosphere by convection and ir radiation. Since the upper ocean is considerably warmer than the lower atmosphere, a warming atmosphere will slow the cooling of the ocean over time (less heat transferred), and result in heat building up in the ocean until equilibrium is reached. There is a lag because the heat capacity of the ocean is so much larger than the atmosphere. Say this process takes 80 years or so to approach equilibrium. At the end of this we have a warmer ocean in equilibrium with the atmosphere. Why would this then heat the air an additional amount? All the excess heat is stored in the ocean, not the atmosphere.

    You ask, what I think the following warm-phase will look like after the PDO shifts back to a warm mode. Well we have just gone through 20 to 30 years of a warm phase Atlantic AND Pacific oceans, and I think it would look something like that. Temperatures rose at a rate of about 0.17C per decade during this period. What I don’t understand is how you get to 2 to 4 C temp increases by 2100 with only relatively short periods of these accelerated warming rates.

  9. David B. Benson says:

    Beefeater — The solution to obtaining the climate to that enjoyed in the Holocene (which we have just left for the Antropocene) is simple to state: return the CO2 level to that enjoyed during the Holocene, about 280 ppm.

    Anything substantially more will have (is having) long term effects of the climate. Such as last summer’s melt of sea ice in the Arctic.

  10. Frank says:

    “the unusual coolness in January was aided by a winter weather fluctuation”
    So, the a global average drop temperature of 0,6 degrees in one year is possible due to whether? The freeze in the middle east, Russia, Eastern europe, Nothern africa, South africa, Australia, china, USA etc is then explained?
    Why is it so important to IPCC not to look at the sky, our sun, and take a close look whats going on? IPCC is very very rapidly loosing everyones trust right now. check this from NASA:
    http://aftermathnews.wordpress.com/2008/01/13/nasa-solar-cycle-may-cause-dangerous-global-cooling-in-a-few-years-time/

  11. Frank says:

    The CO2 levels has been almost 20 times higher than the 280ppm you want. Heres some CO2 basics: CO2 reflects heat at a specific wavelenght. If you add more CO2 in the atmosphere, this wanelength is so to speak already taken.
    This means, the first 20 ppm CO2 in the atmosphere gives around 1,4 degrees celsius greenhouse warming. If you raise the concentration from 20ppm to 40 ppm, the additional warming is only 0,3 degrees. And the human made increase from 280ppm t0 380ppm can physically only create an additional warming of 0,1 degrees. The Solar activity drop right now will lead to a 2 – 2,5 degrees in the coming years. The 0,6 fall from jan 2007 to jan 2008 may be a fluctuation, but we will soon see even lower temperatures. Sorry…

  12. David B. Benson says:

    Frank said “The CO2 levels has been almost 20 times higher than the 280ppm you want.” Not since the first primates, much less Hom sapiens.

    Your calculation of the CO2 forcing appears to be wrong. Cite an authoritative reference. The radiative forcing of 280 ppm –> 385 ppm is about 1.5 W/m^2. That is lots and lots.

    Frank alos said “The Solar activity drop right now will lead to a 2 – 2,5 degrees in the coming years.” Again I believe this to be completely incorrect. Cite an authortative reference.

    What will occur, for about the next 30 years, is a PMO shift to stronger La Ninas and weaker El Ninos. This has nothing to do with solar irrradiance variations.

  13. John Mashey says:

    (back from conference)
    Bob:

    I think it’s more complicated than that, starting with fact that ocean is heated by or gives up heat to the atmosphere, not just heated by sunlight. I’ll think about it some more, but for now:

    Study Figure 2 in the Hansen, Nazarenko paper.
    In the IPCC AR4:
    Chapter 5, especially Figure 5.4 on energy content changes in the Earth, in sections 5.1 and 5.2.

    Also, sections 3.5 and 3.6.

  14. Hank Roberts says:

    “Frank” links to what he claims is a NASA story. It’s not.
    It’s a crank site, picked up by gullible PR and spin and amateur “climate science” sites fixed on turning every idea in one direction.

    Check it out for yourself; search on terms from Frank’s source:

    http://www.google.com/search?q=nasa+solar+cycle+50

    Damn, they got me playing their game again.
    http://en.wikipedia.org/wiki/Image:Close-up_of_mole.jpg

  15. Bryson Brown says:

    Beefeater– Yes, climate will change in the long run– but the threat we face is rapid change, change so fast that plants and animals have little chance of adapting or migrating in response. It’s all in the rate–we’re now driving a change that will lead to widespread extinctions, rapid rise in sea levels and substantial changes to a climate system that humans are very dependent on. Slowing things down and limiting the damage is essential if we hope to leave our children and grandchildren a healthy world.

  16. JKB says:

    The only problem that I have with Hansen’s explanation, is that he is quick to point to this little temporary La Nina, but completely dismisses that El Ninos have played a great role in proping temperatures up for the last 10 years.

    Much of the average for the 2007 year is contributed by an El Nino warmed Janurary 2007. Comparing GISS monthly L-S data to CPC ENSO data, we find that temperatures warmed from -0.7 to +0.4 (borderline el nino conditions) between 1-01 and 4-02. No consequence, temps rose right along with it. El Nino or near El Nino conditions remained in tact from 4-02 all the way through 2-07, with the exeption of a short dip during the last of 05/beginning of 06 (in which temps fell, but then went right back up with the full blown El Nino of the later half of 06 into 07).

    It seems to me that all you people arguing over this climate stuff engage in nothing but a bunch of hand waving, cherry picking perspectives to support your own cause, when in reality, half the arguments made are just as good arguments for both sides.

  17. Larry Coleman says:

    Frank says, “This means, the first 20 ppm CO2 in the atmosphere gives around 1,4 degrees celsius greenhouse warming. If you raise the concentration from 20ppm to 40 ppm, the additional warming is only 0,3 degrees. And the human made increase from 280ppm t0 380ppm can physically only create an additional warming of 0,1 degrees.”

    This is a common misconception. CO2 is not saturated where it counts: in the upper atmosphere. CO2 raises the surface temperature, not by absorbing IR from the surface (all of which is absorbed), but by absorbing IR about seven miles up. Increasing CO2 increases the altitude where IR is able to escape; i.e., it raises the tropopause. An increase in surface temperature follows from the lapse rate.

    The point is that at an altitude of seven miles there is very little CO2 so it is nowhere near saturation. The last ppm of CO2 has almost as much effect as the first ppm

  18. richard schumacher says:

    In summary: La Nina does not stop global warming. La Nina merely exposes cold deep ocean water, which absorbs heat and temporarily slows or stops atmospheric temperature increase. When La Nina stops atmospheric temperature increase resumes.

  19. mark says:

    Interestingly, the lack of sunspot activity in the new cycle has caused the world to cool 0.7 degree Celsius in only one year (Jan 2007 to Jan 2008). Some scientists are warning that this void of sunspot activity will cool the earth to such a degree that global warming will look like a drop in the bucket. Despite this, reports continue to circulate perporting that global warming is on an accelerated pace (species are threatened, the Arctic is melting, etc). Certainly only time will tell, but I believe the global warming theory will evaporate over time — much like the fears about Y2K. You can be sure, however, that global warmers won’t go down without a fight. They have accumulated far too much money and power to quietly hand it back.

  20. Dave says:

    You are correct, Mark – they won’t go down quietly – it will take some time.

    The anti-Plate Tectonics folks would not release their hold on power until 50 years had passed… Poor Alfred Wegner, the brilliant originator of Plate Tectonics, died before his theory become standard science and was seen by most as a “denier” of their “well established theories” of giant submerged land bridges connecting the continents… If I am to be smeared with the “denier” label, I wear it proudly, like Wegner did a mere 90 years ago.

    I absolutely disagree with C02 driving the climate – ludicrous! To dismiss the sun? Such chutzpah! And beyond arrogance.
    Carbon is a fantastic gift that increases crop yields worldwide and is no more a ‘pollutant’ than sunlight or air! Settled science? If it’s settled, it ain’t science, it’s propaganda. Or politics…

    Humans do a lot of damage – heck, I’m for Nuclear power plants and against Coal because of MERCURY that is a by-product of coal-powered stations. No need to fight against imaginary threats, we’ve got tons and tons of actual problems – that’s where we need to tackle the REAL demons.

    But I can see it’s far, far too late for rational thought – somebody get a rope! Hang the industrialized countries, quick, before anyone questions!!

  21. amd says:

    Dave,

    A while back there was a post regarding “deniers” who think their ideas are novel and that everyone ‘someday’ will realize what they thought, was right all along. I applaud you to reference Wegner, but for every Wegner, there was a 100 others with novel ideas, which are still…well…wrong! As far as you ‘settled’ theory goes, you’re arguing semantics. Most here know what the scientific process involves. From your statement you could just as easily completely refute the theory of evolution, which I don’t think you would do.

  22. sesli chat says:

    A while back there was a post regarding “deniers” who think their ideas are novel and that everyone ’someday’ will realize what they thought, was right all along. I applaud you to reference Wegner, but for every Wegner, there was a 100 others with novel ideas, which are still…well…wrong! As far as you ’settled’ theory goes, you’re arguing semantics. Most here know what the scientific process involves.

  23. Some scientists are warning that this void of sunspot activity will cool the earth to such a degree that global warming will look like a drop in the bucket. Despite this, reports continue to circulate perporting that global warming is on an accelerated pace (species are threatened, the Arctic is melting, etc). Certainly only time will tell, but I believe the global warming theory will evaporate over time — much like the fears about Y2K.

  24. seslialmanya says:

    Some scientists are warning that this void of sunspot activity will cool the earth to such a degree that global warming will look like a drop in the bucket. Despite this, reports continue to circulate perporting that global warming is on an accelerated pace (species are A while back there was a post regarding “deniers” who think their ideas are novel and that everyone ’someday’ will realize what they thought, was right all along. I applaud you to reference Wegner, but for every Wegner, there was a 100 others with novel

  25. Cynthia says:

    One way to keep the climate stable, Beefeater, IS FOR PEOPLE TO STOP EATING BEEF! Grazing cattle– destroying the rain forests, growing soy beans for cattle, and methane from cow poop, is a huge contributer to global warming! It’s bad for our health, bad for the animals, and AWFUL for the climate! Get over your beef-eating and you stop a big portion of climate problem!

  26. I think it’s more complicated than that, starting with fact that ocean is heated by or gives up heat to the atmosphere, not just heated by sunlight