An 840-page report from the White House said Tuesday the narrative over climate change has "moved firmly into the present." The report, the National Climate Assessment, attributes the change in weather patterns over the least 50 years to the burning of fossil fuels.
The report drew fire from critics of President Barack Obama.
James Taylor, a senior fellow at the conservative Heartland Institute, said the report was written by alarmists and environmental activists.
"This laughably misleading report is the predictable result when hard-core environmental activists are chosen to write up a climate assessment for, and subject to the approval and revisions of, the Obama administration," he said Tuesday.
But Jon Huntsman, chairman of the Atlantic Council and former Republican governor of Utah, accused his fellow party members of clinging too strongly to dogmatic narratives.
"Denying the science will only hinder [Republican's] chance for success," he wrote Tuesday in the New York Times.
The assessment finds the U.S. average temperature has increased by as much as 1.9 degrees Fahrenheit since record keeping began in 1895.