Eschew Obfuscation

Independent Summary For Policymakers (ISPM)

Posted by Max Dunn Fri, 29 Feb 2008 21:07:00 GMT

The Intergovernmental Panel on Climate Change (IPCC) is the scientific body that researches climate change for the United Nations (UN) and released their Fourth Assesment Report (AR4) in 2007. There are numerous experts participating in the IPCC, and a lot of good science is contained in these reports.

However, there is a big problem with the summary that is included with the IPCC report – the Summary For Policymakers (SPM). This summary is not written by the scientists themselves but by unnamed bureaucratic delegates from the participating countries. As such, they tend to oversimplify and bias the actual results contained in the full report.

So I found that the Independent Summary For Policymakers to be more balanced and representative of the actual report than the SPM itself. The ISPM was prepared by qualified experts, but who were not themselves IPCC chapter authors. The ISPM was subject to expert review and the reviewer’s responses are tabulated so there is a clear record to the extent that the reviewers agreed or disagreed with the ISPM.

While there are many areas where the conclusions of the ISMP are similar to those of the SPM, here are some highlights of the ISPM where its emphasis differs:

• The climate is subject to potential influence by both natural and human forces, including greenhouse gas concentrations, aerosols, solar activity, land surface processes, ocean circulations and water vapor.
• The IPCC gives limited consideration to aerosols, solar activity and land-use change for explaining 20th century climate changes.
• There is no globally-consistent pattern in long-term precipitation trends, snow-covered area, or snow depth.
• There is insufficient data to draw conclusions about increases in extreme temperature and precipitation.
• There is insufficient data to conclude that there are any trends in Antarctic sea ice thickness.
• There are historical examples of large, natural global warming and cooling in the distant past. The Earth is currently within a warm interglacial period, and temperatures during the last interglacial period were warmer than present.
• Many climate models are incapable of simulating important aspects of the current climate, and models differ substantially in their projections.
• Attributing an observed climate change to a specific cause like greenhouse gas emissions is not formally possible, and therefore relies on computer model simulations.

Some of these conclusions may be surprising, but remember these are not the conclusions of a group trying to discredit global warming but of the IPCC body itself.