CO2 warming effect cut by 65%, climate sensitivity impossible to accurately determine

Watts Up With That? ^ | October 12, 2010 | Anthony Watts

[Ernest_at_the_Beach]

Estimated CO2 Warming Cut By 65%

Submitted by Doug L. Hoffman, Resilient Earth via ICECAP

Any competent researcher involved with the science behind climate change will admit that CO2 is far from the only influence on global climate. It has long been known that short-lived greenhouse gases and black-carbon aerosols have contributed to past climate warming. Though the IPCC and their fellow travelers have tried to place the blame for global warming on human CO2 emissions, decades of lies and erroneous predictions have discredited that notion. For anyone still clinging to the CO2 hypothesis, a short perspective article on the uncertainty surrounding climate change in Nature Geoscience has put paid to that notion. It states that not only did other factors account for 65% of the radiative forcing usually attributed to carbon dioxide, but that it is impossible to accurately determine climate sensitivity given the state of climate science.

In “Short-lived uncertainty?” Joyce E. Penner et al. note that several short-lived atmospheric pollutants – such as methane, tropospheric ozone precursors and black-carbon aerosols – contribute to atmospheric warming while others, particularly scattering aerosols, cool the climate. Figuring out exactly how great the impacts of these other forcings are can radically change the way historical climate change is interpreted. So great is the uncertainty that the IPCC’s future climate predictions, which are all based on biased assumptions about climate sensitivity, are most certainly untrustworthy. As stated in the article:

It is at present impossible to accurately determine climate sensitivity (defined as the equilibrium warming in response to a doubling of atmospheric carbon dioxide concentrations) from past records, partly because carbon dioxide and short-lived species have increased together over the industrial era. Warming over the past 100 years is consistent with high climate sensitivity to atmospheric carbon dioxide combined with a large cooling effect from short-lived aerosol pollutants, but it could equally be attributed to a low climate sensitivity coupled with a small effect from aerosols. These two possibilities lead to very different projections for future climate change.

All truthful climate researchers know these facts, yet publicly the party line is that catastrophic changes are in the offing and CO2 emissions are to blame. The perspective authors argue that only by significantly changing the amounts of these other pollutants and carefully measuring the impact on global climate over a period of several decades will science be able to figure out what is going on. “Following this strategy, we will then be able to disentangle the warming and cooling contributions from carbon dioxide and short-lived pollutants, hence placing much tighter constraints on climate sensitivity, and therefore on future climate projections,” they state. See chart below, enlarged here.

And they said it was all carbon dioxide’s fault.

Most of the factors under discussion have relatively short lifetimes in the atmosphere, several less than two months. We do know how the relative influences of these various substances (referred to by climate scientists as “species”) may change in a warming climate. It is also not clear how to reduce short-lived species under present conditions but the uncertainties in atmospheric chemistry and physics must be resolved if Earth’s environmental system is to be understood. Again quoting from the paper:

Of the short-lived species, methane, tropospheric ozone and black carbon are key contributors to global warming, augmenting the radiative forcing of carbon dioxide by 65%. Others – such as sulphate, nitrate and organic aerosols – cause a negative radiative forcing, offsetting a fraction of the warming owing to carbon dioxide. Yet other short-lived species, such as nitrogen oxides, carbon monoxide and volatile organic compounds, can modify the abundance of both the climate-warming and climate-cooling compounds, and thereby affect climate change.

Quantifying the combined impact of short-lived species on Earth’s radiative forcing is complex. Short-lived pollutants – particularly those with an atmospheric lifetime of less than two months – tend to be poorly mixed, and concentrate close to their sources. This uneven distribution, combined with physical and chemical heterogeneities in the atmosphere, means that the impact of short-lived species on radiative forcing can vary by more than a factor of ten with location or time of emission. The situation is further complicated by nonlinear chemical reactions between short-lived species in polluted areas, as well as by the interactions of clouds with aerosols and ozone. These processes add further uncertainty to the estimates of radiative forcing.

Unfortunately, climate models neither accurately deal with local effects of these pollutants nor are the complex interactions among these substances understood. That not withstanding, the report is clear – CO2 does not account for even a majority of the warming seen over the past century. If other species accounted for 65% of historical warming that leaves only 35% for carbon dioxide. This, strangely enough, is in line with calculations based strictly on known atmospheric physics, calculations not biased by the IPCC’s hypothetical and bastardized “feedbacks.”

Of course, the real reason for the feedbacks was to allow almost all global warming to be attributed to CO2. This, in turn, would open the door for radical social and economic policies, allowing them to be enacted in the name of saving the world from global warming. The plain truth is that even climate scientists know that the IPCC case was a political witch’s brew concocted by UN bureaucrats, NGOs, grant money hungry scientists and fringe activists.

Now, after three decades of sturm und drang over climate policy, the truth has emerged – scientists have no idea of how Earth’s climate will change in the future because they don’t know why it changed in the past. Furthermore, it will take decades of additional study to gain a useful understand climate change. To do this, climate scientists will need further funding. Too bad the climate science community squandered any public trust it may have had by trying to frighten people with a lie.

Be safe, enjoy the interglacial and stay skeptical. Read full post here.

Icecap Note: Whatsmore, this totally ignores the other external and internal global factors like solar, ocean multidecadal cycles related to variations in the thermohaline circulation or ocean gyres.

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Here is the paper at Nature Geosciences:

Short-lived uncertainty?

Joyce E. Penner¹, Michael J. Prather², Ivar S. A. Isaksen^3,4, Jan S. Fuglestvedt⁴, Zbigniew Klimont⁵ & David S. Stevenson⁶

1. University of Michigan, Ann Arbor, Michigan 48109-2143, USA
2. University of California, Irvine, California 92697, USA
3. University of Oslo, PO Box 1022, Blindern, 0315 Oslo, Norway
4. Center for International Climate and Environmental Research (CICERO) Oslo, PO Box 1129 Blindern, 0318 Oslo, Norway
5. International Institute for Applied Systems Analysis (IIASA), Schlossplatz 1, 2361 Laxenburg, Austria
6. School of Geosciences, The University of Edinburgh, Edinburgh EH9 3JN, UK.

Correspondence to: Joyce E. Penner¹ e-mail: penner@umich.edu

---

Abstract

Short-lived greenhouse gases and black-carbon aerosols have contributed to past climate warming. Curbing their emissions and quantifying the forcing by all short-lived components could both mitigate climate change in the short term and help to refine projections of global warming.

---

Earth’s climate can only be stabilized by bringing carbon dioxide emissions under control in the twenty-first century. But rolling back anthropogenic emissions of several short-lived atmospheric pollutants that lead to warming — such as methane, tropospheric ozone precursors and black-carbon aerosols — could significantly reduce the rate of climate warming over the next few decades^{1, 2, 3}.

 

[Ernest_at_the_Beach]

This is a :

Peer Reviewed Study:

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And from the comments section:

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j.pickens says:

October 12, 2010 at 11:46 am

“Earth’s climate can only be stabilized by bringing carbon dioxide emissions under control in the twenty-first century.”

Gotta put that in there, even though the entire article appears to show how the CO2 menace has been vastly overstated.

[Army Air Corps]

Ping.

[Ernest_at_the_Beach]

ping.

[Paladin2]

"the truth has emerged – scientists have no idea of how Earth’s climate will change in the future because they don’t know why it changed in the past."

Thus there is NO "Climate Science", only efforts to develop same.

[The Cajun]

“Earth’s climate can only be stabilized by bringing carbon dioxide emissions under control in the twenty-first century.”

We'll know they have it under control when all the plants start dying from suffocation.

[DarthVader]

Someone finally is starting to get it from the physical chemistry and thermodynamic perspective.

[Ernest_at_the_Beach]

fyi

[steelyourfaith]

Thanx Army Air Corps & Ernest_at_the_Beach !

 

Beam me to Planet Gore !

[Ernest_at_the_Beach]

But they are being careful with their language so they won’t impact the flow of the research grants....

[Ernest_at_the_Beach]

From the Comments:

*******************************EXCERPT***********************************

Theo Goodwin says:

October 12, 2010 at 11:47 am

I salute the authors of the paper for their genuine humility as scientists. I haven’t read the paper and do not know the details at this time, but the authors’ frank admission of what is not known is exactly what has been needed in debates on climate change. These authors are moving the discussion of climate change onto a scientific basis and away from the hysteria that has fed into IPCC reports and other efforts to influence policy decisions.

[Carry_Okie]

Earth’s climate can only be stabilized by bringing carbon dioxide emissions under control in the twenty-first century.

Gives a whole new meaning to the term "money quote."

[B4Ranch]

http://www.freerepublic.com/focus/f-bloggers/2604521/posts

‘Global warming is the greatest and most successful pseudoscientific fraud I have seen in my life’

[Paul Pierett]

Thank you. Global cooling is simmering on schedule.

Greenhouse gases cannot replace the lost of solar energy.

Paul

[Ernest_at_the_Beach]

From the comments:

*****************************************EXCERPT****************************************

peakbear says:

October 12, 2010 at 2:01 pm

I’m still not sure that everyone understands that CO2, even with positive feedbacks added, can’t trap any heat in the atmosphere directly, as witnessed by it cooling down by 10-20 degrees (or more in certain areas) easily every night. The only significant place energy could be trapped is the ocean, hence why Argo ‘is it’ for longer term temperature trends, and why El Nino/La Nina influence things so much. I assume when people have blamed a recent hot (or cold) spell on Global Warming they have measured the sea surface temperature nearby to explain why…

I’m from the UK where the sea is obviously a very important factor in our weather, I do always wonder what explanation people come up with to relate say, hot (or cold) temperatures in Alice Springs to CO2 as I can’t see how it could influence anything without warming the entire ocean by a lot all around Australia.

[Carry_Okie]

Even more obvious is that the IR adsorption spectrum of CO2 is almost entirely shadowed by water vapor, of which there is vastly more. Yet the thugs in the control business don't want to regulate water vapor emissions at all. Why?

Fuel cells make water vapor, and the owners of the oil and gas business are heavily invested in minerals necessary to make catalysts.

[Ernest_at_the_Beach]

I think we need to see the paper....

Another observation from the comments:

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wsbriggs says:

October 12, 2010 at 2:02 pm

Most of you would do well to read the paper, not just the post. One clue is the airplane in the troposphere, this isn’t a “hey, it’s not man after all” paper. It really is a “Hey, it’s worse than we thought!” paper. Anytime the word polutants is used, pay attention. Rarely does that mean that Mother Nature is messing with us.

[MichaelAsher54]

Stop Cap & Trade & $7 per gallon gas!

[coconutt2000]

Someone finally is starting to get it from the physical chemistry and thermodynamic perspective.

There's another valid way to approach the problem?

I've tried to explain the complicated nature of atmospheric chemistry and thermodynamics to people. Unfortunately they are more comfortable with the lie they can understand than the truth that they can't.

[SunkenCiv]

Thanks Ernest_at_the_Beach.

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[ConservativeMind]

Ping of interest.