The 2009 State of the Climate Report is a comprehensive appraisal of Earth’s climate by more than 300 authors from 48 countries and portrays all aspects of the climate system. Observations span the atmosphere, land, and ocean from the poles to the equator, and confirm that the past decade was the warmest on record and that the Earth has been growing warmer over the last 50 years. The report, summary, and supplemental materials are available.