Speaking at the American Renewable Energy Day summit in Aspen, Colo., former President Jimmy Carter called for a tax on carbon emissions and lamented the “nutcases in our country who don’t believe in global warming.”

Fox 31 Denver reports:

Carter also lamented that the United States lags behind most other developed countries in the percentage of its energy that’s drawn from renewable sources.

“The biggest problem we have right now is some nutcases in our country who don’t believe in global warming. I think that they are going to change their position because the evidence of the ravages of global warming is coming or is already there.”

Carter isn’t impressed with the current president’s work on climate.