The U.S. energy secretary says the debate about climate change reminds him of the old argument that smoking isn't bad for you.
Steven Chu also urged greater investment in clean energy as he spoke Tuesday in Paris to an International Energy Agency meeting of energy ministers and industry leaders.
He says that because the evidence of climate change is growing more compelling and the price is oil is likely to rise, countries must turn to clean-energy production.
Chu criticized attempts to "muddy the waters" on climate change science.
He said the debate in the U.S. reminds him of what he "heard as a young person growing up about how cigarette smoking was not really bad for your health."