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:
Dr Burns says:
February 4, 2013 at 2:12 pm
“Theory. Zero evidence that CO2 has ever caused any warming.”
Exactly. It seems that those who persist with invoking the “radiative greenhouse effect” THEORY still don’t understand the results of Robert Wood’s 1909 greenhouse study, which showed that not even the glass in a glass greenhouse has the ability to heat through “backradiation” of IR. If the glass can’t do it, the atmosphere certainly cannot.
Nor do these people seem to understand the ideal gas law. If I add one atmosphere (1000 mb) to a planet the size of the earth, I have raised the temperature of that planet by 273K. Of course, I have to keep adding heat each day to the gas to maintain this temperature (to make up for the losses to space), but that is easily accomplished (and easily demonstrated) by simple heat storage in the water and the atmosphere. The Sun heats the planet directly, and we don’t need to resort to backradiation of IR to explain the warmth on Earth’s surface.
Perhaps this would help understanding of the gas law: The ideal gas law is: PV = nRT, where P is pressure, V is volume, n is the number of moles of gas, R is the gas constant and T is the temperature (degrees K). You can rewrite this as: T = PV/nR. Let’s choose R as 0.082 (L)(atm)/(K)(mol). Let’s look at one mole of air at one atmosphere, which is 22.4 l in volume. Thus,
T = (1)(22.4)/(1)(0.082)
T = 273 K
Please note, radiation freaks, that the equation has no variable relating to IR or whether the gas is a “greenhouse gas.”
Also please note that the lapse rate is dependant upon ONLY the acceleration due to gravity and the heat capacity of the gas (lapse rate = g/Cp). Sooo, IF back radiation was capable of doing ANYTHING at all WRT temperature, then the lapse rate for IR-interactive gases would be lower than the lapse rate for such gases as oxygen and nitrogen. But the lapse rate for pure CO2 is actually MUCH HIGHER, at about 9.5/0.8 = 11.9 K/Km!
But, I will probably AGAIN get no feedback that takes me to the task on facts. I’ll get more strawmen and unrelated junk….
Mosher writes “you cant get negative values unless you deny that c02 blocks IR. Since C02 does block IR, it is a positive forcing.”
If you lived in the Stratosphere you’d have a very different view of what CO2 did and you’d call it a negative forcing. So simply put, if the weather in the troposphere flattens out the possible temperature gradient increase due to CO2 and the increased cooling in the Stratosphere remained, then that could accelerate the cooling.
I’m not saying thats what happens and it doesn’t match our measurements but on “physics alone” without special reference to our measurements I dont think you can categorically rule it out either. I dont think any level of forcing claimed is a slam dunk.
Anthony said,
“Climate sensitivity to CO2 might have be different in the past and may be in the future, depending on ambient conditions of the time….and there are many factors that change with time. Then there’s feedbacks, which are also not static/linear with time.”
Indeed, there is no reason to believe that sensitivity inferred from the paleo record is in any way representative of the current sensitivity. It is completely plausible, in fact logical, that the sensitivity to any forcing during an ice age is positive as water vapor rises from the very low levels then present. It is completely plausible that climate sensitivity is near zero or negative now. It is implausible IMO to believe that sensitivity is significantly above 1 now. We perhaps can know what sensitivity was based on observation, we can never know what sensitivity will be in the future. That is the nature of non-linear dynamics.
So the climate models are not working quite right. No problem. Dial down the sensitivity. Good.
But they still don’t know what the hell the Earth is doing. Why? They don’t study that. They only study the models. Besides, what does Earth have to do with this little exercise?
@Bill Illis
>”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).”
Surely they are not that stupid? Really? Really, really??
Crispin in Waterloo says:
February 4, 2013 at 7:35 pm
“Surely they are not that stupid? Really? Really, really??”
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Oh no, it’s far, far worse than that. They never correctly modelled the role of radiative gases in a moving atmosphere. It turns out these gases are critical for continued convective circulation below the tropopause. If the atmosphere was not able to radiate IR to space from the mid to upper troposphere, convective circulation would stagnate and our atmosphere would heat dramatically. They have not just gotten the magnitude of the effect of radiative gases in our atmosphere wrong. They have gotten the sign of their effect wrong.
jae says:
February 4, 2013 at 6:14 pm
Yep……precisely correct!
Thank you.
After he went all in with Peter Gleick, I could give a rat’s ass what Revkin does or thinks. Orwell described his type in his editorial from Sept. 1, 1941.
Sorry, Sept 1 1944
http://www.telelib.com/authors/O/OrwellGeorge/essay/tribune/AsIPlease19440901.html
Crosspatch, well said …….. Post of the year IMHO. The one with the questions that is, can’t seem to cut and past it. Oh well!
Tommy Boy
Steven Mosher states the definition of Climate Sensitivity at 11:42 am:
“Sensitivity: the change in temperature per change in Watts.
So, for example if the sun increases by 1 watt, and the earth warms by 1 watt you have a
sensitivity of 1. If the sun goes up by 5 watts and the earth warms by 1 C you have 1/5 or
a sensitivity of .2”
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Mr. Mosher is using a different definition of Climate Sensitivity than is generally agreed on. Climate Sensitivity is usually defined as the temperature change that the Earth should experience due to a doubling of CO2 in the Earth’s atmosphere.
When Mosher states that “you can’t less than 1” he is using a different definition than scientists such as Spencer or Lindzen.
Steven Mosher says:
February 4, 2013 at 10:50 am
==========================
Stephen, are you certain it is above 1?
Thank you to the various commenters making the point that climate is a chaotic system and it is unlikely this number is stable over a variety of variables.
OT: I always find it amusing that I first read about chaotic systems in James Gleick’s Chaos. And James is Peter’s brother. Too bad Peter couldn’t understand the implications of James’ book to climate science.
Stepher Mosher says:
“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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I suspect another Hansen misadventure into Geology. Havn’t seen the new one but the last was hanging his hat on some paper alleging that the collision of India and the uplifting of Tethys sediments accelerated weathering and sucked the CO2 from the air to produce the long temperature slide from the Eocene to the Pleistocene.
Sure, a bit more weathering but nothing new in tectonic history. All of this supposes that India simply took a notion to sail up there when it was actually shot like a cannonball between two transform faults in an exorcism of seafloor spreading that surely must have spewed oxides of Carbon and Sulfur and…
Some guys could screw up a shoot sandwitch.
There has never been a snowball earth,even during the Young Dim Sum the egg did not freeze, although it came closest then is spite of massive atmospheric Carbon.
KevinR says:
February 4, 2013 at 8:56 pm
Matthew R Marler says:
February 4, 2013 at 4:31 pm
Several units of measurement are used, with the temperature change per doubling of CO2 being equal to 3.7 * temperature change per watt/metre^2. I prefer the units Steven is using, temperature change per 1 W/m2 change in forcing, it avoids one assumption (that doubled CO2 leads to 3.7 W/m2 change in forcing).
However, the use of either definition is fine, it makes no more difference than expressing a weight in tonnes or kilograms, it’s just different units.
w.
PS—Note the typo in Steven’s statement (highlighted)
And yet George Monbiot wrote as recently as 27 August 2012;
“As I’ve warned repeatedly, but to little effect, the IPCC’s assessments tend to be conservative. This is unsurprising when you see how many people have to approve them before they are published.” Bold is mine.
Reference: http://www.monbiot.com/2012/08/27/the-heat-of-the-moment/
So the activists don’t care that the science has moved on.
They still believe it’s the end of the wrold.
Tin-foil hats all round.
Note that any claimed “sensitivity warming” must be ON TOP OF the LIA-rebound trend line. About, say. 0.6°C/Century. WHERE is this trend subtracted from the “observed” sensitivity warming? Show your work.
CO2 doubling sensitivity can be easily calculated from the two sets of data:
GISS temp: http://data.giss.nasa.gov/gistemp/graphs_v3/Fig.A2.txt
NOAA geomagnetic http://ngdc.noaa.gov/geomagmodels/IGRFWMM.jsp
while for the CO2 rise only two reference points 1940 = 305 ppm, 2010 = 403 ppm are required as shown here
http://www.vukcevic.talktalk.net/00f.htm
which even predicts (correctly) that the current global temperatures plateau will last at least another 6 years.
Hansen ‘may got it right for the wrong reason’, but Gavin with his maths degree from the UCLhas no excuse; should have gone to the other side of the town to the Imperial where they use to teach proper engineering (ask Joanna Haigh).
vukcevic:
Your post at February 5, 2013 at 3:23 am says
I don’t know whether or not ” the current global temperatures plateau will last at least another 6 years”. Please explain how you know that the prediction is “correctly” predicted when the next 6 years have yet to occur.
Richard
george e. smith says:
February 4, 2013 at 5:42 pm
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)
George E. Smith for Leader! This comment is profound, unlike most on here. Any trained thinker new to this debate would look at a chart of temps vs CO2 concentration and immediately see that they are completely unrelated.
Mosher, let’s see your red herring response to Smith!
Konrad says:
February 4, 2013 at 8:01 pm
“It turns out these gases are critical for continued convective circulation below the tropopause. If the atmosphere was not able to radiate IR to space from the mid to upper troposphere, convective circulation would stagnate and our atmosphere would heat dramatically. They have not just gotten the magnitude of the effect of radiative gases in our atmosphere wrong. They have gotten the sign of their effect wrong.”
Interesting. I gather that someone has put together a radiative/convective model that captures this. I hope it gets peer-reviewed and published quickly.
Question: In the absence of CO2, wouldn’t water vapor do the trick?
Steven Mosher says:
Nope.cant be less than 1 or you cant get out of an iceball earth.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Sorry Steve I would rather look at the theories of scientists who do not have a dog in the fight or a ‘political agenda’. Never forget that the whole basis for the existence of the IPCC is to condemn the human race and make us pay ‘Indulgences’ for our sins against GAIA. The IPCC mandate states:
This means the IPCC and the scientists on the taxpayer teat are not only not looking for any other possible climate influences, they are actively and aggressively suppressing those ideas because if any other climate influences are identified the CO2 climate sensitivity must be modified and the politicians and social reformers lose their whip for driving humanity. See Comment
Dr. Nir Shaviv has a decent interpretation of what is going on in CAGWland.
An alternate theory of Ice Ages is presented by Dr. Nir Shaviv
I took a look at the UV and EUV/ozone influence on the climate HERE (lots of links as usual)
Graph C14 vs O18 (Cosmic Ray Flux vs Temperature)
Graph low cloud cover (%) vs Cosmic Ray decrease (%) 1980 to 2006 (Wiggle Matches a heck of a lot better than CO2 vs temp over the same period)
Graphs from:
Cosmic Rays and Climate
Another interesting Article by Dr. Shaviv: The oceans as a calorimeter “I few months ago, I had a paper accepted in the Journal of Geophysical Research. Since its repercussions are particularly interesting for the general public, I decided to write about it….”
All the so called research ”proving” that CO2 causes climate change comes from models that assume that CO2 causes climate change. This is a circular argument, pure sophistry, as Joseph Postma says and proves mathematically on his excellent web site:-
http://www.climateofsophistry.com
Well worth a visit.
What do our temperature records look like when adjusted for ln (CO2 concentration) and ln (CO2 equivalent concentration)?
“Any trained thinker new to this debate would look at a chart of temps vs CO2 concentration and immediately see that they are completely unrelated.”
I would rephrase that – remember the unknown unknows- as: from available information and knowledge is impossible to find any relation…