What is the most important climate condition to keep tabs on? We have recently mentioned the record-low Arctic sea-ice extent, but hurricanes this year seem to be getting the most attention because of timing of Hurricane Isaac (I know of no evidence suggesting that the Arctic sea-ice has such a direct impact on U.S. politics!).
It’s important to avoid getting lost into single indicators as the climate system is complex, with many different parts interacting with one another. The American Meteorological Society (AMS) recently put out a statement on climate change, referring to a wide range of different climate indicators (here is a link for the most common ones). The AMS is not alone – the National Academy for Sciences (NAS) is also concerned about our climate and its many aspects: A fairly recent movie called Climate Change: Lines of Evidence provides a comprehensive overview.