The U.S. Senate has voted overwhelmingly, 98 to 1, to approve an amendment affirming that climate change is real and "not a hoax."

The vote came on an amendment to legislation that aims to force approval of the controversial Keystone XL pipeline, which would carry oil from the Canadian oil sands to the United States.

Senators opposed to the pipeline, who say it would help accelerate climate change by encouraging mining of oil sands, are using votes on the bill as an opportunity to force Republican senators to take a stand on whether climate change is real. Some Republican lawmakers have dodged the issue, saying they lack the scientific credentials to evaluate the evidence for climate change. One lawmaker, Senator James Inhofe (R–OK), has even called climate change a "hoax."

The amendment, from Senator Sheldon Whitehouse (D–RI), takes a veiled jab at Inhofe, asking simply whether it is “the sense of the Senate that climate change is real and not a hoax."

In a surprise this afternoon, Inhofe rose before the vote to ask to become a co-sponsor of the Whitehouse amendment. Scattered applause greeted his remarks. "Climate is changing," he said, "and climate has always changed." The hoax that he has talked about, he suggested, is that there are people who think they are so "arrogant" and "powerful" that "they can change climate."

Whitehouse said he hoped the amendment would lead to greater efforts to address the impacts that climate change is having on the oceans and other ecosystems.

Inhofe was one of the last senators to vote, in favor. The lone no vote came from Senator Roger Wicker (R–MS).