The Day Before --

There has been an enormous amount of press coverage of climate change in the last couple of years. The coverage has ranged from reports that the US government is suppressing the statements of scientists to reports of predictions of the disappearance of ice in the Arctic Ocean during our lifetimes. Al Gore's "An Inconvenient Truth" is nominated for an Oscar. Friday is the day for release of "Climate Change 2007" by the Intergovernmental Panel on Climate Change (IPCC, http://www.ipcc.ch/ ). Even before its release the report is generating controversy. A few days ago the Associated Press ran a story saying that some scientists think the report understates the impact of melting ice sheets. A local newspaper wrote about the global warming propaganda. "Virtually Certain", "Alarming" -- a web search of the news finds headlines of all sorts, often as the lead for the same story. What is right? What's reasonable to expect?

With all of the news about the melting of sea ice, glaciers in the Alps and Andes, and ice sheets in Greenland and Antarctica, what the IPCC has to say about the ice should receive a lot of attention. Ice is a critical part of the climate puzzle, an important player in water supplies, and one of the most active areas of research. Where there is active research, there is always controversy from competing ideas. But we know much more about how ice melts now than we did even five years ago. We know that large amounts of ice can melt quickly.

The most anticipated pieces of the report will be the predictions of temperature increase and sea level rise. Should we expect refinement in these predictions -- a narrowing of the range? If the lower end of this range is higher than in the 2001 report, then some will say that the situation looks worse. If the higher end of the range is not as high as in the previous report, then some will say that the outlook is better. The real questions, however, are whether or not the predictions and impacts are reliable enough to act on? How do we use this knowledge?

I hope to post a review of the IPCC report this weekend.

--ricky