Originally posted at Yahoo! Finance

Sen. John Thune (R-SD), chair of the Senate Republican Conference, admitted in an Fox News interview on Sunday that human activity has likely caused some climate changes.

This is a big step, though in the same segment Thune expressed negative feelings on the US-China climate deal reached last week, and promoted the Keystone XL pipeline.

As a member of a party often noted for its representatives’ unwillingness to cooperate with national climate policy or even for their outright climate denialism, Thune’s first remark was a solid acknowledgment that human-caused climate change is occurring.

“Well, look, climate change is occurring, it’s always occurring, Chris,” Thune said in the interview with Chris Wallace on Fox News Sunday. “There are a number of factors that contribute to that, including human activity. The question is, what are we going to do about it and at what cost?”