Recent Evidence for Reduced Climate Sensitivity

[jffryh]

theory of gravity is only theoretical because you can't bring planets and stars down to earth and into a science lab, so go ahead and jump off that cliff you'll be just fine.

[ozricbish]

i'm not really bothered about who/what is causing climate change, although this is a cogent thesis. It seems that the 550 plus ppm that will suffocate us all is totally disregarded...

[guillermogefaell]

Don't be so worried. Life thrieved on Earth with CO2 concentrations of 1000 ppm and even 2000 ppm for millions of years.

[Dave26851]

False

In fact the newest science shows that atmospheric concentrations have remained practically stable since 1850.

It is shown that with those uncertainties, the trend in the airborne fraction since 1850 has been 0.7 ± 1.4% per decade, i.e. close to and not significantly different from zero.

[askljdf12325]

@Dave26851 I believe you have misunderstood the scientific study.

Numerous Murdoch papers and Watts Up With That also completely botched their reporting on it.

It refers not to the amount of co2 in the atmosp. (increasing rapidly), but to the percentage of emitted co2 that remains in the atmosp. (currently stable, same as what the IPCC said 2 years ago). It's like the difference between the % of humans having children (i.e. stable at approx 50%), versus the global population (increasing rapidly)

[Dave26851]

We are talking about the anthroprogenic atmospheric co2, the report shows that the airborne fraction since 1850 has been 0.7 ± 1.4% per decade, i.e. close to and not significantly different from zero This is significant in that this is not in keeping with the amount of co2 emitted by humans, so there must be either be more sinks, or co2 has a shorter residence time.

Also, I have not seen any report by the IPCC saying that it is steady, could you please direct me to your evidence for this?

[askljdf12325]

Is this what you are talking about. AR4 Working Group 1 7.3.2.1:

"From 1959 to the present, the airborne fraction has averaged 0.55, with remarkably little variation when block-averaged into five-year bins (Figure 7.4). Thus, the terrestrial biosphere and the oceans together have consistently removed 45% of fossil CO2 for the last 45 years, and the recent higher rate of atmospheric CO2 increase largely reflects increased fossil fuel emissions."

[askljdf12325]

Atmospheric concentration != airborne fraction

One is increasing rapidly (and I've never ever seen someone argue that this is not occurring); the other is stable. Well actually, that's not certain: the Knorr 2010 study you are thinking of, after applying filtering for ENSO and volcanic activity, finds there is a slight, but statistically significant increase in the airborne fraction.

DailyMail and WUWT both seriously botched their reporting on this issue. WUWT retracted. DailyMail did not.

[askljdf12325]

Whilst I have your attention, the real question is "Will the airborne fraction increase in the future?"

Theoretically it seems that it would. Studies such as La Quere 07 indicate that the Southern Ocean has been absorbing less co2 since '81. The IPCC AR4 is inconclusive on this issue, as it should be.

Of course, in theory it is possible that new sinks may emerge, in fact humans have the power to create such sinks, but we would need to either be lucky or more resourceful. I suggest the latter.

[jimbo1490]

@Dave26851 Also the 'isotopic fractionation (fingerprint) of fossil carbon is largely missing for the present atmosphere. I fossil emissions have cause all or most of the CO2 rise, then It should be ~21-25%, but mass-balance studies show only ~3-5% of the carbon in the atmosphere is fossil sourced. This suggest a much shorter residence time, as affirmed in a plethora of measurement studies conducted over the last 50 years, the latest, Essenhigh, 2009.

[attorp]

Realclimate, an internet site hosted by climate scientists, has responded to Spencer's research. See the May 21, 2008 entry titled "How to Cook a Graph in Three Easy Lessons."

[Gwynne66]

RealClimate is not really objective on this issue. They are a small group of scientists dedicated to pushing the IPCC view of global warming. Their rebuttals of other scientists who challenged the AGW orthodoxy (e.g. Svensmark, Shavic, Veizer, Patterson, Ian Clarke, etc. etc.) have been shown to be inaccurate. I see not reason to take this one seriously.

[GreenRiver72]

Agreed, they are just another part of the corrupt research community where articles that make huge assumptions on poor data pass "peer-review" and those that make legitimate, humble claims on less-biased data are said to be wrong .. on the basis of the poor data ... huh???

[attorp]

Interesting reasearch which definitely deserves consideration. I don't think the average Joe can draw too many conclusions without seeing a reponse from other experts like James Hansen and Andrew Weaver. I notice no mention of the Arctic which is melting and of the threat of methane (many times more potent than CO2) from melting permafrost. Also, a one degree warming is nothing to scoff at...that's average whereas Arctic is already seeing much more and that's where the danger lies.

[EasyEs]

Because everyone who looks at the paleo climate records can not find the warming signal from the last glacial recessions in the Northern Hemisphere which must have produced massive methane bursts in the atmosphere (we know it did). What it suggests is that internal variability in the climate system countered it.

[GreenRiver72]

attorp, very good points -- every time I hear people wailing this way and that about CO2 I want to remind them about CH4 whose warming effect is linear not logarithmic ... The arctic is melting ... but do recall the vast majority of the resultant warming from human emissions will be confined to above 500mb and inside the tropics/subtropics. The poles are warming (according to "data"), but you cant tell me their is logical evidence to say its mostly from human emissions.

[RMKumpf621]

Dr. Roy Spencer is the best there is in his field of science and climatology (Gore and Hansen aren't even in the same league)

Check out Dr. Spencers excellent book, "Climate Confusion".

[Bostonyooper]

I am in the middle of reading that as we speak. It really does make one re-think man made global warming doesn't it?

[Dave26851]

Well it is only one of a string of papers and evidence which makes me think twice. I've even thought a third and fourth time and continually get the same answer. I would like somebody to provide real convincing evidence, so my faith in the scientific community is restored.

[jimbo1490]

@RMKumpf621 In fact, the All of the 'Superstars' of the climate scientists are in the 'skeptic' camp. Roy Spencer, John Christy, Richard Lindzen and Fred Singer are the top men in the world in climatology. Without these men's work, we would not even have such a thing as 'Satellite Temperature Data'. Who do the 'Warmers' have in their camp? The LIAR Michael Mann, the LIAR James Hansen and the LIAR Phil Jones.

[minilemur]

Excellent research and presentation!

[AnthonySG1]

Very good! Nice work.