At the Law School on Wednesday, Sen. John F. Kerry criticized the United States for not taking stronger action on carbon emissions.

In uncharacteristically blunt terms, Sen. John F. Kerry delivered an impassioned plea for action on climate change at the Law School Wednesday, rebuking the nation’s “screwed up” priorities and criticizing both the U.S. government and Harvard for not taking stronger action to reduce carbon emissions.

“The level of irresponsibility with respect to environmental issues is beyond comprehension,” Kerry said, noting that the U.S. has ignored international efforts to cap emissions and is trailing most of the developed world in using renewable fuels for electricity generation. “How do we expect to lead the world if we’re so dedicated to our head-in-the-sand, ostrich policy?”

Kerry, the 2004 Democratic presidential nominee and Massachusetts’ junior senator, had harsh words for the Bush administration, accusing it of failing to take meaningful steps to avert climate change.

“We don’t have time to screw around with this,” Kerry said. “They are avoiding this in the most shocking and inappropriate way.”

Kerry was no less severe with Congress, taking it to task for its funding priorities and noting that the recent energy bill passed by the Democratic Congress would put in place fuel economy standards by 2020 that are lower than standards China will enact next year.

“Our priorities are so screwed up, it’s depressing,” he said. “If, instead of spending seven to nine billion dollars a month in Iraq, we put seven to nine billion dollars a year into this, there would be a stunning output.”

Kerry said that while he is working with like-minded colleagues—notably Sen. Joseph I. Lieberman (I-Conn.) and Sen. John W. Warner (R-Va.)—to pass bills to reduce carbon emissions, the fact that no law has emerged from Congress reflects the power of interests working against the legislation.

He said that there is a “powerful set of arguments” for businesses to want to prevent climate change, noting that major insurance companies could face significant losses if rising ocean levels and severe storms increasingly threaten Florida and the Gulf Coast.

Once businesses support climate change legislation, he said, it will be much easier to enact mandatory carbon dioxide caps.

“It legitimizes this in many ways for the [political] right, who wait for a green light from the business community,” Kerry said.

The senator’s speech on climate change came amid a recent drive among campus activists to lower Harvard’s carbon imprint. In December, Dean of the Faculty Michael D. Smith expressed support for a plan to reduce Harvard’s greenhouse gas emissions.

But Kerry criticized President Drew G. Faust’s refusal to sign the American College and University President’s Climate Commitment—an agreement of university and college presidents to reduce emissions of greenhouse gases by 80 percent by 2050 that has been signed by 440 university presidents.

“Every university and college in America that is dedicated to teaching students correctly and instilling moral values has to make a commitment to adopt this [pledge],” Kerry said. “And any university with a multi-billion dollar endowment such as Harvard has an even greater responsibility.”

Students who attended the event said Kerry’s speech was refreshing for its candor.

“He was very frank about how the politics surrounding climate change have unfortunately frustrated good policy,” said second-year law student Andrew A. Friedman.

—Staff writer Natasha S. Whitney can be reached at nwhitney@fas.harvard.edu.