BBC: US President Barack Obama has promised to outline his plan to deal with climate change in a speech at Georgetown University on Tuesday.
He said it would include measures to reduce carbon pollution and to lead global efforts to fight climate change.
Mr Obama has said repeatedly he would tackle climate change, but has been blocked by Congress.
He is believed to be planning to pass the new measures by executive action, meaning he will bypass Congress.
"There's no single step that can reverse...