First, as posted on my son’s weblog in
the global temperature anomaly is essentially irrelevant in terms of climate change issues that matter to society and the environment. Even in terms of global warming, it is a grossly inadequate measure, as discussed, for example, in
Pielke Sr., R.A., 2003: Heat storage within the Earth system. Bull. Amer. Meteor. Soc., 84, 331-335.
Pielke Sr., R.A., 2008: A broader view of the role of humans in the climate system. Physics Today, 61, Vol. 11, 54-55.
The global average surface temperature, however, unfortunately, has become the icon of the IPCC community and in the policy debate. As my son wrote in his post
“The debate over climate change has many people on both sides of the issue wrapped up in discussing global average temperature trends. I understand this as it is an icon with great political symbolism. It has proved a convenient political battleground, but the reality is that it should matter little to the policy case for decarbonization.”
This political focus has resulted in Richard Muller’s testimony on his Berkeley Earth Surface Temperature project yesterday to The Science, Space and Technology Committee of the House Of Representatives. In his (in my view, premature) testimony he makes the following claims
“The world temperature data has sufficient integrity to be used to determine global temperature trends”
“…. we find that the warming seen in the “poor” stations is virtually indistinguishable from that seen in the “good” stations.”
“The Berkeley Earth agreement with the prior analysis surprised us, since our preliminary results don’t yet address many of the known biases”?
The contradictory statement in the last sentence from his testimony contradicts the first two sentences.
All his study has accomplished so far is to confirm that NCDC, GISS and CRU honestly used the raw observed data as the starting point for their analyses. This is not a surprising result. We have never questioned this aspect of their analyses.
The uncertainties and systematic biases that we have published in several peer-reviewed papers, however, remain unexplored so far by Richard Muller and colleagues as part of The Berkeley Earth Surface Temperature project. We summarized these issues in our paper
Pielke Sr., R.A., C. Davey, D. Niyogi, S. Fall, J. Steinweg-Woods, K. Hubbard, X. Lin, M. Cai, Y.-K. Lim, H. Li, J. Nielsen-Gammon, K. Gallo, R. Hale, R. Mahmood, S. Foster, R.T. McNider, and P. Blanken, 2007: Unresolved issues with the assessment of multi-decadal global land surface temperature trends. J. Geophys. Res., 112, D24S08, doi:10.1029/2006JD008229