A massive U.S. report concludes the evidence of global warming is stronger than ever and that more than 90 percent of it has been caused by humans.

The conclusion contradicts a favorite talking point of senior members of the Trump administration.

A 477-page report released Friday said it's "extremely likely" -- meaning with 95 to 100 percent certainty -- that global warming is man-made, mostly from carbon dioxide through the burning of coal, oil and natural gas.

Energy Secretary Rick Perry and Environmental Protection Agency chief Scott Pruitt have said carbon dioxide isn't the primary contributor to global warming.

Since 1900, the report says Earth has warmed by 1.8 degrees (1 degree Celsius) and seas have risen by 8 inches. Heat waves, downpours and wildfires have become frequent.