WASHINGTON (Reuters) - President Barack Obama lampooned congressional scepticism over climate change, saying that lawmakers who baulk at tackling air pollution are either blind to science or cowed by extremists.
In a speech to the League of Conservation Voters on Wednesday, the President enumerated the steps he has taken to slow pollution and rein in emissions that scientists say have trapped heat in the earth's atmosphere.
One such measure, a sweeping plan to cut power plant pollution unveiled earlier this month, stirred ire among Republicans and some Democrats, particularly in parts of the country that produce coal.
The President mocked those who question the science behind climate change or the urgency of addressing the problem, which has emerged as a legacy issue for his presidency and a polarising topic in November congressional elections.
"In most communities and workplaces, et cetera, when you talk to folks, they may not know how big a problem, they may not know exactly how it works, they may doubt that we can do something about it, but generally they don't just say, no, I don't believe anything scientists say," he said, to laughter.
He likened evidence that human activity causes global warming to the medical profession's confidence in the health risks of smoking.
"I'm not a doctor either, but if a bunch of doctors tell me that tobacco can cause lung cancer, then I'll say, OK," he said. "Right? I mean, it's not that hard."
Some lawmakers may secretly believe that man-made climate change is real but are afraid to admit so for fear of "being run out of town by a bunch of fringe elements that thinks climate science is a liberal plot", Mr Obama said.
Republican and some Democratic lawmakers argue that the Obama administration's tougher environmental regulations will hold back economic growth and hurt employment.
The President has sought in announcements and public appearances this week to draw attention to his efforts to slow climate change.
The White House said on Wednesday that Mr Obama's policies would eventually cut almost three billion tonnes of carbon pollution between 2020 and 2025, develop renewable energy to power almost two million homes, train more than 50,000 solar industry workers and save people billions of dollars on their energy bills.