Update 8/12/2010 am): I e-mailed the following to Kevin
The interview that the Weather Channel did with us on Monday was quite instructive as it highlighted areas of significant agreement among us as well as the areas of disagreement. I did post today on one comment you made; see
and would like to see if you would respond in a comment that I can post. It is with respect to the reasoning for your conclusion of a 5-10% increase in precipitation in the flood areas of Pakistan and China. Any other comments on what I wrote would be welcome also.
Following is Kevin’s response
Trenberth, K. E., 2010: Changes in precipitation with climate change./
Climate Research, /submitted. [PDF] <http://www.cgd.ucar.edu/cas/Trenberth/trenberth.papers/Trenberth_precipChange_ClimResMar10.pdf>
Trenberth, K. E., C. A. Davis and J. Fasullo, 2007: Water and energy
budgets of hurricanes: Case studies of Ivan and Katrina . /J. Geophys.
Res./, *112*, D23106, doi:10.1029/2006JD008303. [PDF]
Trenberth, K. E., and J. Fasullo, 2007: Water and energy budgets of
hurricanes and implications for climate change. /J. Geophys. Res./,
*112*, D23107, doi:10.1029/2006JD008304. [PDF]
and many other references therein
Unfortunately, the interview is not on-line at the Weather Channel, but they have promised to send a DVD with this show which we will plan to convert and post.
In the interim, I wanted to comment on one statement that Kevin made (paraphrased below) that
…with global warming there is probably about a 5-10% increase on the precipitation that has occurred with the events in Pakistan and China…
This is an interesting conclusion. First, we need a basis for this number, and I have e-mailed Kevin to respond to this request. Second, if we accept this as true, it still means that the devastating floods would still likely have occurred even with 5-10% less rainfall.
The Economist has an informative article on the floods in Pakistan titled “Swamped, bruised and resentful” [subscription required]. With respect to the reasons for the flood damage, the article writes
“The deluge, which was many times the usual monsoon and fell farther north and west than usual, has exposed the lack of investment in water infrastructure, including big dams, much of which was built in the 1960s. The removal of forest cover may also have allowed rainwater to drain faster into the rivers. “
Clearly, there is a climate component in terms of where the anomalous rainfall fell. However, the failure to reduce the region’s vulnerability from foods by adequate water resource management (the lack of infrastructure development) and the environmental damage from deforestation (the accelerated runoff) significantly magnified the seriousness of this disaster. This is why we need the bottom-up, resourse-based perspective that I mentioned in my answer on the Weather Channel, and in my papers and blog posts; e.g. see
In our paper
Pielke Sr., R., K. Beven, G. Brasseur, J. Calvert, M. Chahine, R. Dickerson, D. Entekhabi, E. Foufoula-Georgiou, H. Gupta, V. Gupta, W. Krajewski, E. Philip Krider, W. K.M. Lau, J. McDonnell, W. Rossow, J. Schaake, J. Smith, S. Sorooshian, and E. Wood, 2009: Climate change: The need to consider human forcings besides greenhouse gases. Eos, Vol. 90, No. 45, 10 November 2009, 413. Copyright (2009) American Geophysical Union
“The water cycle is among the most significant components of the climate system and involves, for example, cloud radiation, ice albedo, and land use feedbacks [NRC, 2003]. Regional and local variations in water availability, water quality, and hydrologic extremes (floods and droughts) affect humans most directly.”
“Risk assessments require regional- scale information. Thus, in addition to the current approach based on global climate models, local and regional resource- based foci are needed to assess the spectrum of future risks to the environment and to the resources required for society. For example, by regulating development in floodplains or in hurricane storm surge coastal locations, effective adaptation strategies can be achieved regardless of how climate changes.”
“We recommend that the next assessment phase of the IPCC (and other such assessments) broaden its perspective to include all of the human climate forcings. It should also adopt a complementary and precautionary resource- based assessment of the vulnerability of critical resources (those affecting water, food, energy, and human and ecosystem health) to environmental variability and change of all types. This should include, but not be limited to, the effects due to all of the natural and human caused climate variations and changes.”