Boxer's comments followed claims by Sen. James Inhofe (R-Okla.) — Capitol Hill's leading climate skeptic — that global warming science remains unsettled.
Inhofe again pointed to e-mails among climate scientists hacked from a prominent British research institute in late 2009 in what became known as the "Climategate" affair. He called it a major scandal.
Inhofe and other skeptics say the messages revealed efforts to squelch data that undercut evidence of warming. But multiple outside reviews cleared the scientists of claims that they tried to cook the books.
Inhofe is co-sponsoring bills that would strip the Environmental Protection Agency's power to regulate greenhouse gas emissions.
The dominant — but not unanimous — view among climate scientists is that the earth is warming and that human actions such as burning coal and oil are a major cause.