Higher temperatures and rising sea levels are just two of the future risks facing the US, according to the country's third national climate assessment (NCA).
Described by the White House as the most comprehensive scientific assessment of climate change and its impacts across every region of America, NCA 2014 reveals that, since 1991, temperatures have averaged 1°F to 1.5°F higher than the 1901–1960 average over most of the country, except for the southeast. It predicts that in the next few decades, warming will be between 2°F and 4°F in most areas, and, under a high emissions scenario, up to 10°F by 2100.
Heavy downpours are intensifying nationally, says the NCA, with the largest increases in the Midwest and northeast. More frequent and intense extreme precipitation events are projected for all regions. Most northern states are forecast to experience more precipitation in the winter and spring, while the southwest, including California, is projected to experience less, particularly in the spring.
According to the findings, 64 million people living in the northeast, from Maine to the District of Columbia will in future be affected by heatwaves, more extreme precipitation events, and coastal flooding due to sea level rise and storm surge.
In the southeast, from Virginia to Florida and Louisiana, the NCA forecasts that declining water availability will increase competition for it. This area will also be at greater risk of extreme weather events, including hurricanes, such as Hurricane Sandy, which hit the Atlantic coast states in 2012.
