Paul Biggs from the University of Birmingham, UK, sent me the following summary of a presentation by Roger Pielke Sr. There is so much interesting information on the potential human impact on climate beyond a focus on carbon dioxide:
"Roger Pielke Sr, a respected climatologist of some 30 years, gave an interesting presentation of his perspective on climate science entitled 'Regional and Global Climate Forcings - The Need to Move Beyond a Focus of the Radiative Forcing of the Well-Mixed Greenhouse Gases' at the The 2006 Earth’s Radiative Energy Budget Related to SORCE Meeting in Washington.
The general conclusions that I draw from Pielke’s work are as follows:
Humans are significantly altering the global climate, but in a variety of diverse ways beyond the radiative effect of carbon dioxide.
In terms of climate change and variability on the regional and local scale, the IPCC Reports, the CCSP Report on surface and tropospheric temperature trends, and the U.S. National Assessment, have all overstated the role of the radiative effect of the anthropogenic increase of CO2 relative to the role of the diversity of other human climate climate forcing on global warming, and more generally, on climate variability and change.
Pielke calculates the fraction of global warming due to the radiative forcing of increased atmospheric CO2, using the current IPCC framework on climate forcings:
http://www.grida.no/climate/ipcc_tar/slides/large/06.01.jpg.This includes new findings on artic ozone, methane, albedo, and aerosols/black carbon with forcing calculated to be about 26.5%. This contrasts with the IPCC view of 48%.
He suggests new or under-recognized human climate forcings including:
biogeochemical effect of CO2, nitrogen deposition, land-use/land-cover change, glaciation effect of aerosols, thermodynamic effect of aerosols, surface energy budget effect.Global and regional climate models have not demonstrated skill at predicting climate change and variability on multi-decadal time scales.
A postitive feedback is required in order to significantly amplify the radiative forcing of added carbon dioxide.
There is, as of yet, no evidence that atmospheric water vapor concentrations have increased (see http://climatesci.atmos.colostate.edu/2006/04/03/new-global-precip-papers-trend-is-zero-or-positive/).
Moreover, water vapor also changes phase (into liquid and ice clouds and precipitation) which greater complicates the actual climate response to added CO2 and other well-mixed greenhouse gases.
Attempts to significantly influence regional and local-scale climate based on controlling CO2 emissions alone is an inadequate policy for this purpose.
The needed focus for the study of climate change and variability is on the regional and local scales. Global and zonally averaged surface temperature trend assessments, besides having major difficulties in terms of how this metric is diagnosed and analyzed, do not provide significant information on climate change and variability on the regional and local scales.
It is this instrumental data that gives the plot of a hockey stick shape, grafted onto proxy data. Furthermore, if, for example, the temperature of an area of the desert were to increase from plus 40 degrees celsius to 41 degrees, while at the same time an equal area of the Antarctic decreased from minus 40 to minus 41, the average temperature of the earth would stay constant.
However, under the Stephan-Boltzman equation, more radiation would be emitted by increasing the temperature of the desert, than the radiation loss from Antarctica. Pielke will shortly have a paper published in JGR, which introduces this problem.
Global warming is not equivalent to climate change. Significant, societally important climate change, due to both natural and human climate forcings, can occur without any global warming or cooling.
The spatial pattern of ocean heat content change is the appropriate metric to assess climate system heat changes including global warming. Pielke examines the significant upper ocean cooling from 2003 reported by Lyman et al, 2006 (http://www.noaanews.noaa.gov/stories2006/s2704.htm) to a depth of at least 750m, which was not predicted by climate models.
He cites 2 papers which support the diagnosis: A 2004 Science article by E. Pallé, P. R. Goode, P. Montañés-Rodríguez, and S. E. Kooninentitled 'Changes in Earth’s Reflectance Over the Past Two Decades' and a follow-on 2005 Geophysical Research Letters paper by Pallé E., P. Montañés-Rodriguez, P. R. Goode, S. E. Koonin, M. Wild, and S. Casadio entitled 'A multi-data comparison of shortwave climate forcing changes' (http://www.agu.org/pubs/crossref/2005.../2005GL023847.shtml ).
Finally, I must point out that Pielke says all of this is not a reason not to seek to reduce CO2 emissions."
Thanks Paul for the summary and also to Luke, for emphasising to me the importance of getting this information up as a new post/thread.
Among all these comments I find very little to reassure me that the Earth's thermostat can be adjusted, what the ideal temperature is, how we will deal with people who are disadvantaged by others' notions of ideal temperature, and so forth, especially since the notion of "climate control" has yet to emerge as something more than merely a plot element in science fiction novels.
Gavin -it was my comment I think you'll find.
See previous post in recent weeks on Tuvalu for up to date links on sea level issues. Pielke's issues may potentially complicate some of the projections.
Paul’s comment - Pielke Sr isn't a 'solar man' is curious
However “his main interests are mainly in land use change and ocean heat storage” is good enough for me particularly the ocean heat storage bit.
What is the ocean’s capacity for delay in sea level and climate change?
Thanks for the info Paul. I am currently reading this book at the link you have, and so far, it seems full of useful information.
If only every comment on this site were as measured and useful as Paul's quotes and paraphrase's of Pielke Sr . thanks PB. (and Luke)
Pielke Sr isn't a 'solar man' his main interests are mainly in land use change and ocean heat storage.
Interesting post from Pielke on his blog:
My answer as to whether we should seek to reduce the amount of CO2 that we exhaust into the atmosphere, is certainly yes. Indeed, I have concluded that the biogeochemical effect of added CO2 may actually have a greater effect on the climate system than the radiative effect of CO2.
However, it has not been recognized in the climate assessments. nor by policymakers, that added CO2, by itself, can explain only a fraction (at most about 28% according to the estimate I posted on the Climate Science weblog) of the reported climate system heat increases (global warming) over the last several decades.
Even more importantly, global warming is but one of many climate responses, and CO2 is but one of a number of first order climate forcings. Climate forcings, such as land use/land cover change and the thermodynamic effect of anthropogenic aerosols, for example, can very significantly change the climate system, but yet they may not produce global warming or cooling.
We need to consider these diverse climate forcings in terms of how they could alter the lives of future generations. Focusing primarily on CO2 as a solution to the human alteration of climate is oversimplistic and misleading to policymakers.
To move society and policymakers forward on this discussion, I recommend that energy policy be seperated from climate policy. The 2005 National Research Council is a way forward with respect to the climate issue, but, unfortunately, has not been widely read.
National Research Council, 2005: Radiative forcing of climate change: Expanding the concept and addressing uncertainties. Committee on Radiative Forcing Effects on Climate Change, Climate Research Committee, Board on Atmospheric Sciences and Climate, Division on Earth and Life Studies, The National Academies Press, Washington, D.C., 208 pp.
http://www.nap.edu/openbook/0309095069/html/
“Perturbations” to the top-of-atmosphere budget, and the surface budget is just dragged along, accommodating itself to whatever changes in surface temperature are demanded in order to be able to satisfy the top of atmosphere budget” – hmm I could make some wise crack about folk caught up the in the PD, or difference between budgets top and bottom re the turmoil as we go on but……..
while hunting a definition for “perturbations” re above this popped out front-
Quote - “Roger raises a good question: "What temperature is actually important to them?" What I try to do in my stories is figure that out and answer it in as many useful ways as possible. So we had a drought. How dry was it really compared to the longest record we've got? Growing season, for example, is of relevance, meaning first freeze of fall, which is then linked to overnight temperatures, so I'll tell 'em that, in Albuquerque, 2005 is likely to be one of the warmest by that measure in history. And then what about the days - which haven't been so hot? But then I expect them to wonder whether this is part of anything larger, at which point I think the globally averaged” surface temperature is a useful data point to help them understand where their local experience fits into the bigger picture”
Did I mention frost first?
Everything we wanna know is on the www and there is nothing new under the jolly old sun except AGW!
careful Gavin, you're recommending personal responsibility. Who knows where that might lead us.
Gavin some interesting thoughts on the local level:
http://www.agu.org/pubs/crossref/2005.../2005GL023624.shtml
Realclimate interprets:
They (Philipona et al.) understand fully well that water vapor acts as a feedback to amplify forcing due to CO2 increase, and make this clear in their paper. This paper does not, however, deal directly with the problem of whether European warming can be attributed to CO2 increase. It only shows that, whatever mechanism is causing the warming of the atmosphere in this region, the surface warming is being amplified by low level water vapor feedbacks. {Wow !}
Press reports failed to note that the water vapor feedback discussed in Philipona et al. is not the same water vapor feedback usually discussed in connection with global warming. It is instead a surface water vapor feedback which adds additional surface warming on top of the usual things we talk about. The effect is already incorporated in the climate models used in IPCC forecasts, but the new observational study will be useful as a reality-check.
The fact is, that even if the diligent Swiss authors of this paper had found that increasing CO2 contributed nothing to the changes in the surface budget, this would have in no way contradicted our understanding of the way anthropogenic greenhouse gases influence climate. For the most part, surface temperature changes are determined by perturbations to the top-of-atmosphere budget, and the surface budget is just dragged along, accommodating itself to whatever changes in surface temperature are demanded in order to be able to satisfy the top of atmosphere budget. It is impossible to understand the greenhouse effect without thoroughly understanding this point
They estimate this to be about one third of a Watt per square meter. This is not in bad agreement with estimates from detailed radiation models run by the authors, which say that the change in surface radiation due to the 12ppm CO2 increase between 1995 and 2002 should be about one fourth of a Watt per square meter. It is striking that the changes in the Earth's surface radiation budget due to anthropogenic greenhouse gases are so profound that they can be directly observed on a regional scale, over such a short time period.
oops Luke got in first on oceans!