The National Climate Assessment, a mass study commissioned by the White House, describes how Americans are already feeling climate change impacts, from flooding in New York City to droughts that wipe out crops in Kansas and fires that devastate California. Alaska was the most severely impacted and temperatures there were found to be rising at twice the speed of the rest of the USA.
President Barack Obama will use the report as evidence for action as he tries to move ahead with policies on climate change before leaving office in 2017. Last year, in a speech to university students, Mr Obama said he felt a moral obligation "as a president, as a father and as an American" to act.
The White House attempted to pass a national limit on carbon emissions in 2009 but Democrat leaders were unable to rally the votes to get it through Congress. With Republicans now firmly in control of the House of Representatives and threatening to retake the Senate, President Obama is resorting to executive orders - limited actions which do not need Congressional approval.
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