Obama: No time for a meeting of the Flat Earth Society
25 June 2013 Last updated at 20:40 BST
US President Barack Obama has laid out a series of measures aimed at curbing climate change, including limits on emissions from power plants.
In a speech at Georgetown University in Washington DC, Mr Obama said there were multiple solutions to the "very hard problem" of climate change but said he would not waste time debating those who denied it was happening at all.
"We don't have time for a meeting of the Flat Earth Society," he said. "Sticking your head in the sand might make you feel safer but it's not going to protect you from the coming storm."