WASHINGTON — In the summer of 2010, it was Harry Reid, the Senate’s Democratic leader, who squelched his party’s efforts to pass a climate change bill, declaring it could never attract enough votes to pass. In the years since, he has rarely spoken publicly about the issue.

But on Monday night, an impassioned Mr. Reid took to the Senate floor to kick off a nearly 15-hour climate-change talkathon by about 30 Senate Democrats, part of a campaign by a new Senate “climate caucus” to make it a politically urgent issue.

“Climate change is real. It’s here,” Mr. Reid said, adding that it was time to stop acting as if those who ignore it “have a valid point of view.”

“They don’t,” he said. READ ENTIRE ARTICLE