Former vice presidential candidate Rep. Paul RyanPaul RyanRyan appears on Hannity's show President Obama should curb mass incarceration with clemency Senators move to protect 'Dreamers' MORE (R-Wis.) said the Earth’s climate has always changed and pollution from humans might not be the cause.
He outlined his doubts Monday at a forum with businessman Rob Zerban, the longshot Democratic candidate for Ryan’s House seat.
“I don’t know the answer to that question,” Ryan said, according to the Associated Press. “I don’t think science does, either.”
Ryan, a rumored candidate for president in 2016, further said efforts to mitigate climate change are expensive and unproven, AP reported.
He added that the climate has been changing forever and the benefits of fighting it do not outweigh the costs.
Monday’s forum was not the first time Ryan has expressed doubt about the consensus among scientists that greenhouse gas emissions from human activity is warming the Earth.
Earlier this year, for instance, he said claims of climate change and government efforts to stop it are just “an excuse to grow government, raise taxes and slow down economic growth.”
Zerban sharply disagreed with Ryan, saying climate change is serious and humans play a significant role. He called for more investments in renewable energy.