Lower climate sensitivity is getting some mainstream discussion. Last week at WUWT, we had this story: BREAKING: an encouraging admission of lower climate sensitivity by a ‘hockey team’ scientist, along with new problems for the IPCC which is now the most read story on WUWT in the past week.
This morning, WUWT carried this essay from Chip Knappenberger: The yearly lukewarm report which spurred some communication from Andrew Rekvin at NYT about the similar story he just posted today: A Closer Look at Moderating Views of Climate Sensitivity.
Andy just sent me a fascinating exchange from Gavin Schmidt of NASA and the Realcimate blog. Gavin sent sent this note as part of a group e-mail exchange and this is what Revkin forwared to me (and has now posted at Dot Earth):
Andy, I think you may be slightly misrepresenting where the ‘consensus’ on this issue has been. While there have been occasional papers that have shown a large tail, and some arguments that this is stubborn – particular from constraints based on the modern tranisent changes – there has always been substantial evidence to rule these out. Even going back to the 2-11deg C range found in the initial cpdn results in 2005, many people said immediately that the high end was untenable (for instance).
Indeed, the consensus statements in the IPCC reports have remained within the 1.5 – 4.5 range first set by Charney in 1979. James’ work has helped improve the quantifications of the paleo constraints (particular for the LGM), but these have been supported by work from Lorius et al (1991), Kohler et al (2010), etc. and therefore are not particularly radical.
By not reflecting that, you are implying that the wishful thinking of people like Ridley and Lindzen for a climate sensitivity of around 1 deg C is tenable. It is not, and James’ statement was simply alluding to that. For reference, James stated that his favored number was around 2.5 deg C, Jim Hansen in a recent letter to the WSJ quote 2.5-3.5 (based on the recent Palaeosens paper), and for what it’s worth the CMIP5 GISS models have sensitivities of 2.4 to 2.7 deg C. None of this is out of the mainstream.
I sent Schmidt and the group this reply:
In policy circles, including popular calculations of emissions trajectories necessary to avoid a high change of exceeding 2 degrees C. of warming, the hot tail has not been trimmed (unless I’m missing something?).
To me, that says the climate science community — including the Intergovernmental Panel on Climate Change science working group — has not adequately conveyed the reality you state here.
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Anthony: This essay from Pat Michaels is relevant also:
Mr. Mosher
“Nope.cant be less than 1 or you cant get out of an iceball earth.
The lag has nothing to do with it. The lag was predicted before it was discovered and is what one would expect if AGW is true.”
There has been a natural mechanism to get out of “ice ball Earth” as well as its opposite that has been demonstrated clearly during the past 900,000 years of monotonously regular cycles of 100,000-year glacials and 15,000-year interglacials. These periods of natural climate change obviously had nothing to do with the activities of humanity – the ending of the preceding interglacial of the Eemian (125,00 years ago, when it was trending cooler from its high of 8 degrees C warmer and sea level up to 10 meters higher than now) closely resembled our current modest warm period which follows five other warmer periods of the past 10,000 years following the end of the Ice Age (glacial period). Regardless of changes in CO2, these glacials and interglacials demonstrate the natural climate changes that have occurred in some form or other for billions of years. Most recently they have featured, among other characteristics, low atmospheric CO2 and persistent ice at high latitude and glaciers at high altitude. The Greenland ice cap survived the Eemian warming with 75% of its mass intact, and the much warmer than now Holocene Climatic Optimum (9,000 to 5,000 years ago) with very little less loss off mass (most of which is at high altitude and remains frozen the year around).
None of this supports the concept of AGW, and all of it supports the concept of natural climate change.
So how much heat does CO2, 035% of the atmosphere, need to reradiate to warm the other 99.965% of the atmosphere by 1 degree C? 2777 times as much?
Philip Bradley says:
February 4, 2013 at 12:56 pm
that is my understanding too – that it is a net value, irrespective of all other feedbacks in the context of my assumption that it is (as per this article) a CS value for CO2 component only. I believe this because they also add the other forcings separately (aerosols, albedo, etc) in the models – but if I have misunderstood I’ll be happy to stand corrected.
Willis Eschenbach says:
February 4, 2013 at 1:32 pm
I agree with your points – but on calling something a negative sensitivity, as I see it, that is when a feedback ‘overwhelms’ the positive part of the ‘original’ forcing making the net value negative. The actual sensitivity to the original paramter remains the same, yes?
One of the biggest negative feedbacks appears to be clouds. Increasing water vapor as the atmosphere warms resulting in more clouds. This wouldn’t have been the case during a snowball earth period.
Steven Mosher says:
February 4, 2013 at 10:50 am
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No, Sir Mosher. The Knights of Consensus no longer get to “frame the debate”. The Knights of Consensus were routed at Radiative Ridge.
Despite the nondescript black helmets and lowered visors, I was able to identify Sir N.S., J.S. and E.R. in the fray. Was the fourth Black Knight Sir J.D.?
I thought you might enjoy your own cryptic drive by 😉
Steven, the “basic physics” of the “settled science” is wrong. Climate sensitivity to addition CO2 would be indistinguishable from 0.0C. This sorry hoax is all but over. The rubenesque diva is reaching into the props box for the hat with the horns and the buses are warming up.
Theory. Zero evidence that CO2 has ever caused any warming.
If his account of the consensus on sensitivity is true, one would think Gavin would be much more infuriated by assertions of high sensitivity (running to 11 degrees C or more) than he is by “deniers” estimating sensitivity in the range of 1 degree C. I expect Gavin will soon begin denouncing sensitivity estimates exceeding 4 degrees C as hysterical and “anti-science”.
MarkW says:
February 4, 2013 at 1:57 pm
“This wouldn’t have been the case during a snowball earth period.”
Precisely. That is exactly the kind of thing I was referring to here which could cause different behavior in different regimes.
This discussion of “climate sensitivity” is interesting, but it seems that the actual definition of the temperature is remarkably vague (as well as the absurdly narrow assumption that a single global average temperature trend can characterize “climate sensitivity”).
As a starting point for all of these discussions, someone should define where this temperature is measured (e.g. the skin radiating temperature, the 2m temperature, etc). As we have shown, there is quite a bit of uncertainty in finding temperatures that actually could be used to quantify the radiative imbalance of the climate system; e.g. see
Pielke Sr., R.A., C. Davey, D. Niyogi, S. Fall, J. Steinweg-Woods, K. Hubbard, X. Lin, M. Cai, Y.-K. Lim, H. Li, J. Nielsen-Gammon, K. Gallo, R. Hale, R. Mahmood, S. Foster, R.T. McNider, and P. Blanken, 2007: Unresolved issues with the assessment of multi-decadal global land surface temperature trends. J. Geophys. Res., 112, D24S08, doi:10.1029/2006JD008229. http://pielkeclimatesci.wordpress.com/files/2009/10/r-321.pdf
McNider, R.T., G.J. Steeneveld, B. Holtslag, R. Pielke Sr, S. Mackaro, A. Pour Biazar, J.T. Walters, U.S. Nair, and J.R. Christy, 2012: Response and sensitivity of the nocturnal boundary layer over land to added longwave radiative forcing. J. Geophys. Res., doi:10.1029/2012JD017578, http://pielkeclimatesci.files.wordpress.com/2012/07/r-371.pdf
As we have repeatedly urged, global warming (and cooling) should be diagnosed from changes in Joules not a dry bulb temperature.
The breakup has commenced. The cracks in the consensus will widen the longer the temperature standstill continues or cools. All in slow motion, where is my family sized popcorn pack?
Seriously, if we continue to get a widening of the gap of projected and observed temps / new revisions downwards (without major volcanic eruptions) then they are going to have own up and say they were wrong on climate sensitivity. I just can’t see how they can carry on spinning this over the next few years.
Judith Curry is a smart lady. She could see the writing on the wall.
I’m beginning to wonder what Mosher’s connections to Gleick might be?. He was out gaining skeptic street cred within minutes of the Heartland fraud. The silliness he’s been spouting lately is too much for a rational person to take.
As Kuhn pointed out, most scientists don’t question the paradigm, they just work within it.
The paradigm in climate science is the Forcings Model or as I prefer to call it the Forcings Theory.
I think its likely the Forcings Theory is a poor predictor of climate change – in the jargon, it has limited utility.
I have several reasons for thinking this. One of those reasons has already been raised in this thread – forcings are non-linear and can result in negative sensitivity. In fact, I think zones of negative sensitivity are necessary for the climate to be as stable as it is.
The other main reason is I think factors that affect feedbacks may be a better predictor of climate change than changes in forcings. Specifically, things that affect the phase changes of water – aerosols, black carbon, GCRs and potentially others. This relates to the previous point as these factors would change the non-linear feedbacks and shift the zones of negative sensitivity.
As a mere mechanical engineer, I hesitate to venture into the wonderland of ‘climate change’. However, in looking at the graphs at the beginning of this post I have to ask myself why anyone would believe that there is any kind of mathmatically-straightforward relationship between CO2 levels and ‘global temperature’. Climate is such a chaotic system, and we are barely beginning to understand the inputs and their myriad interactions. In reality, who knows what kind of zig-zaggy relationship may exist? Hubris is a sin, especially in scientists. Engineers tend to be more practical, by necessity.
Annan sent an e-mail to Revkin that the latter posted”
“Anyway, there have now been several recent papers showing much the same – numerous factors including: the increase in positive forcing (CO2 and the recent work on black carbon), decrease in estimated negative forcing (aerosols), combined with the stubborn refusal of the planet to warm as had been predicted over the last decade, all makes a high climate sensitivity increasingly untenable. A value (slightly) under 2 is certainly looking a whole lot more plausible than anything above 4.5.”
Jan. 27, 2013 at 12:30 a.m.
–http://dotearth.blogs.nytimes.com/2013/01/26/weaker-global-warming-seen-in-study-promoted-by-norways-research-council/?comments#permid=20
Stubborn Refusal! Bad planet. No dessert for you.
My psychic friend, Miss Cleo scolded me for asking about Gavin. She says any fool can see ‘Real Climastrologists’ will progressively downgrade their projections as the climate continues to refuse to cooperate. No psychic abilities are necessary: Bjorn Lomborg, James Lovelock and James Annan have already abandoned this sinking ship, and the rest of the smart rats will soon follow.
Natural selection will deal with the rest. Let the back-pedaling continue!
Willis Eschenbach says:
“But both the climate sensitivity, and the change in climate sensitivity with temperature, are very, very different in the two temperature regimes of morning and afternoon. It takes much, much more energy to go from 22°C to 23°C than it does to go from 7°C to 8°C. So while the average temperature doesn’t change much, that is highly deceptive. In reality, the dependence of sensitivity on temperature makes a huge difference in how the system actually reacts to changes in forcing.”
Willis, I almost always agree with you completely, although in this case while I agree what you say is true, it is kind of like looking at individual trees when instead you should be looking at the whole forest, I would prefer to define climate sensitivity this way, which is the way it is being portrayed to the general public and that is “Given the earths current average temperature and the way it is measured, what will be the increase in the average temperature (measured in the same way) above current temperature if the CO2 concentration is doubled? Or perhaps what will be the “measured temperature increase when CO2 hits 600ppm as compared to when it was 300ppm?
Jimbo says:
February 4, 2013 at 3:18 pm
Yes, I think JC started her gradual withdrawal some time ago – but to be brutally honest the vast majority of the ‘team’ still need to be hung drawn and quartered in my humble opinion. I am not interested in their motives, peer pressure, government instruction, conspiracy, or anything else – my anger is derived solely from the perspective of science. A real scientist does not make WAG’s or accept the WAG’s of others verbatim. More importantly, a scientist does not ‘sit quietly in the corner’ if they know or even remotely suspect something is not right. These people knew full well that the science they were promoting was not fully sound (I avoid saying it was BS deliberately!) and it is/was BEHOLDEN on them, as scientists to bring this to their peers attention, and, if necessary to blow the whistle on the poor science. To my mind, these people are no better than ‘doctors’ failing to adhere to the hypocratic oath. They sat and watched whilst the scientific method was thrown under a bus, covered in eco-fuel and burnt to a crisp!
Sorry, but as far as I can see – there is absolutely no frickin excuse! This isn’t something like the Mars rover, with limited data, and no chance of checking – this is a subject poured over by thousands of scientists, at vast expense, time and time again – and all the while ignoring or downplaying the unknowns! Net result = bad science.
Finally, we need to remember what might have been if it were not for the valiant efforts of a very few number of skeptics – and I bet a pound to a penny that those ‘team’ members coming out of the woodwork now, would still be in there, burrowing away and still lining their own nests!
@Steven Mosher
>>‘But logically Steven, and taking the ice core records as ‘read’ – it must be less than one, possibly even negative! – because CO2 increase always lags the temperature in the ice cores. ”
>Nope.cant be less than 1 or you cant get out of an iceball earth.
>The lag has nothing to do with it. The lag was predicted before it was discovered and is what one would expect if AGW is true.
Steven that is too far off the mark. There are times when the CO2 does no relate to ice at all. Good heavens. There are well reasoned postulations for coming out of ice ages including but not limited to orbital changes. CO2 leading warming then following it works how exactly? Why does CO2 wait for 1000 centuries before showing us its magic?
The idea that CO2 initiates then lifts the Earth out of ice ages is not tenable. If anything is clear from ice cores it is that the Earth warms first then CO2 rises – from very low levels. Yes it is possible (but unproven) that the following CO2 provides an additional forcing. How much? It is not clear at all. If it was, we would know the forcing value for CO2, which we do not.
Having a negative value is unlikely but also not yet ruled out. On the positive side, feedback mechanisms are necessarily limited based on what we know about feedbacks in quasi-stable systems capable of reaching equilibrium states. The postulated ‘CO2 lag’ supposed that the ocean will be warmed and emit CO2. The oceans are in a permanent state of CO2 deficit because of the many mechanisms that subtract CO2 from it permanently. That is why fresh water in equilibrium (24 hours open to the air) has twice as much CO2 per g than sea water.
Perhaps the ice cores are wrong after all and we are all being misled.
Steven Mosher: Sensitivity: the change in temperature per change in Watts.
Is that universally recognized? Everyone but you seems to be writing about a change in mean temperature per doubling of CO2 concentration.
Steven Mosher says:
February 4, 2013 at 11:29 am
‘But logically Steven, and taking the ice core records as ‘read’ – it must be less than one, possibly even negative! – because CO2 increase always lags the temperature in the ice cores. ”
Nope.cant be less than 1 or you cant get out of an iceball earth.
The lag has nothing to do with it. The lag was predicted before it was discovered and is what one would expect if AGW is true.
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The assumption is that low CO2 caused the Snowball Earths and then high CO2 levels ended them? Climate science can’t think past CO2 causes everything. That is the entire problem.
The last two Snowballs were caused by super-continent Rodinia/Pannotia moving over the south pole 750-715 Mya and 650-615 Mya. Think Antarctica times 15 with only a few small continents not in this grouping near the equator.
The second last Snowball ended with CO2 at 8,000 ppm because super-continent Rodinia broke-up and moved off the south pole – continental drift. The last Snowball ended with CO2 at 12,000 ppm because super-continent Pannotia broke-up and moved off the south pole (they were really the same super-continental grouping, they just had a few different arrangements that drifted across the south pole).
CO2 levels were too low to break up the Snowballs. It was continental drift and Albedo.
Now what was the Earth’s Albedo during these Snowballs. It was close to 50% but climate model simulations are always built assuming Albedo is almost constant at 29.8% (even in the last ice age – believe or don’t).
When you can get your head around the fact that Albedo over glaciers is 60% to 70% to 80%, even the ice age temperature changes and the Snowballs start to make sense and CO2 sensitivity calculations fall to where it is looking today – around 1.25C per doubling.
Will Nitschke says:
February 4, 2013 at 1:10 pm
@Bill Illis
“I have my own version of the above chart which shows where the actual observations to date are and that which takes into account Gavin’s comment about the transient warming timeline.”
How different would the data be if charted unadjusted?
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Its not really different, there is just more up and down ENSO variability etc. I’m not really changing the basic trendline but just removing some of the internal variability.
“This assumes all warming is due to CO2.”
Which we are nearly 100% certain is NOT true. Which leads us to believe the actual sensitivity to a doubling of CO2 is somewhat less. My guess is somewhere between .6 and .9C. There are negative feedbacks that have kept a lid on rising temperatures in the past and those feedbacks have not ceased to exist now….
Well it would be nice if they could admit, that there also is no data supporting a logarithmic relationship in the first place, specially since Temp is up and down and sideways, while CO2 is monotonically upward (plus the 6 ppm annual cycle at ML)
On the WeatherBELL site, Dr. Ryan Maue has an interesting post about January’s worldwide surface temperatures. He uses the data that is put into the models, before they run the computer and come up with our long range forecasts. Although the forecasts are often wrong, especially once you get more than five days into the future, the data the use as a starting point is from top-of-the-line satellites, and is 100% correct. (Or one would really really hope it was correct.) From this data he can get the average worldwide surface temperature on a monthly, weekly, daily and even hourly basis.
What blows me away is how much the average temperature rises and falls, just during the course of a month. I am not talking about a single place, such as Boston. I’m talking about the average 2m temperatures across the entire planet.
If you take the 2m temperatures averaged across the lower 48 states of the USA, it jumped up and down between .5 above normal and .5 below normal five times during January, and averaged out….average. (Or actually, according to Ryan, one one-thousandth of a degree above normal.)
While the yo-yoing of temperatures across the entire earth may not be so extreme, I have seen it vary nearly a degree in a single month. Then we get the average for the entire month, which this past January comes to a tenth of a degree above the 1981-2010 average.
In other words, on a monthly basis we currently are a measly tenth of a degree above “normal.” Our planet is not “running a fever.” If my body temperature was 98.7 rather than 98.6, I doubt my boss would let me skip work.
However, on a weekly, a daily, and even an hourly basis, our planet’s average temperature goes shooting up and crashing down, without any uproar. Nothing goes extinct and the sky doesn’t fall.
The fuss about the average surface temperature of our planet is getting so old even Chicken Little is starting to yawn.