The evidence supports decades-old predictions

One of the reasons why a high confidence is being placed in the 3rd National Climate Assessment, released last week (a congressionally-mandated report by 300 leading climate scientists and experts is that so many of the projections made by the same scientists decades ago have come true:  increases in heatwaves, droughts and severe flooding.

The report concluded that:  "The global warming of the past 50 years is primarily due to human activities, predominantly the burning of fossil fuels.  Over the last 50 years, much of the United States has seen an increase in prolonged periods of excessively high temperatures, more heavy downpours, and in some regions, more severe droughts.  Evidence indicates that the human influence on climate has already roughly doubled the probability of extreme heat events such as the record-breaking summer heat experienced in 2011 in Texas and Oklahoma. In some regions, prolonged periods of high temperatures associated with droughts contribute to conditions that lead to larger wildfires and longer fire seasons."

Download or read the entire report:  http://nca2014.globalchange.gov/  or just the overview and highlights.