The global temperature record shows an average warming of about 1° F over the past century. This warming has been recorded in both the northern and southern hemispheres, and over the oceans, with some areas substantially warmer and others actually cooler. The ten warmest years have occurred since 1983, with seven of them since 1990. Recent evidence shows the 20^th century was the warmest in the last 1,000 years. The 1990’s were the warmest decade and 1998 was the single warmest year of the past millennium.