US President Barack Obama on Friday hit out at naysayers he blamed for peddling "cynical" claims that global warming is a myth to derail a landmark climate change bill in Congress.
Obama warned that the closer the Senate came to passing legislation which has already cleared the House of Representatives, the more opponents would resort to underhand tactics.
"The naysayers, the folks who would pretend that this is not an issue, they are being marginalised," Obama warned in a speech at the Massachusetts Institute of Technology.
"But I think it's important to understand that the closer we get, the harder the opposition will fight and the more we'll hear from those whose interest or ideology run counter to the much needed action that we're engaged in.
"There are those who will suggest that moving toward clean energy will destroy our economy," Obama said, a day after the release of a poll showing fewer Americans see solid evidence of global warming.
"There are going to be those who... make cynical claims that contradict the overwhelming scientific evidence when it comes to climate change, claims whose only purpose is to defeat or delay the change that we know is necessary."