climate science weblog
A Broader Assessment Of Climate Change Science Is Needed
This column summarizes a set of conclusions that have been reached on the Climate Science weblog. Among the most significant is that the IPCC climate change assessments have been too conservative in recognizing the importance of a diverse range of human climate forcings, as identified in a 2005 National Research Council Report, as they alter regional and global climate. As a result, attempts to significantly influence regional and local-scale climate based on controlling CO2 emissions alone is an inadequate policy for this purpose.
A website, Climate Science, was launched in July 2005 to provide a more inclusive venue to communicate climate science to other scientists, the public and the media.
There are a set of conclusions that have become clearer as the peer reviewed papers and reports were discussed on this website. These are:
1. The needed focus for the study of climate change and variability is on the regional and local scales. Global and zonally-averaged climate metrics would only be important to the extent that they provide useful information on these space scales.
2. 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.
3. 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.
4. The spatial pattern of ocean heat content change is the appropriate metric to assess climate system heat changes including global warming.
5. 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 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.
6. Global and regional climate models have not demonstrated skill at predicting climate change and variability on multi-decadal time scales.
7. Attempts to significantly influence regional and local-scale climate based on controlling CO2 emissions alone is an inadequate policy for this purpose.
8. A vulnerability framework, focused on regional and local societal and environmental resources of importance, is a more inclusive, useful, and scientifically robust framework to interact with policymakers, than is the focus on global multi-decadal climate predictions which are downscaled to the regional and local scales. The vulnerability paradigm permits the evaluation of the entire spectrum of risks associated with different social and environmental threats, including climate variability and change.
These conclusions are documented in a wide variety of papers as discussed on the Climate Science weblog. Each of these issues will be discussed in more depth in subsequent comments on Scitizen.