Manhattan ? A curious debate has broken out among American environmental groups, as the Senate balkily starts to focus on the threat of climate change.

Is this REALLY the time to talk about the threat of climate change?

Now, some groups have muted their alarms about wildfires, shrinking glaciers and rising seas. Not because they’ve stopped caring about them — but because they’re trying to win over people who might care more about a climate bill’s non-environmental side benefits, such as “green” jobs and reduced oil imports.

Smaller environmental groups, however, say this is the wrong moment to ease up on the scare because that might send the signal that a weaker bill is acceptable.

At the heart of this intra-green disagreement is a behemoth of an unanswered question: Even after years of apocalyptic warnings about climate change, how much will Americans really sacrifice to fight it?

“It’s a lack of faith in the American public,” said Kieran Suckling of the Center for Biological Diversity, an Arizona nonprofit, talking about the light-on-climate ads used by bigger groups. “If the scientists, the environmentalists in our country do their jobs, and explain the test of climate change, the public will come along.”

“Instead of doing that job,” Suckling said, “we’re running away from it.”

Playing down the threat from a warming climate may come with a cost for environmental groups, if it appears to give senators license to weaken measures aimed at helping the environment, such as limits on greenhouse gas emissions.

Already, the push for energy “made in America” has given industry an opening to press for things some green groups don’t want: more offshore drilling in U.S. waters and more support for the American coal business.

Lou Hayden of the American Petroleum Institute said his group does not debate environmentalists about climate science. But he said it will fight environmentalists on the jobs question, saying that the climate bill would kill more than it would create.

This summer, the House passed a bill that would limit emissions by 2020, using a complex system called “cap and trade” that would allow companies to buy and sell allowances to pollute.

But this week has shown that the Senate will be a much harder sell. On Thursday, a Senate committee voted 11 to 1 to pass a climate measure based loosely on the House legislation, with Republicans boycotting the vote. But a day earlier, a trio of senators said they were coming up with a separate climate bill — making the one passed Thursday somewhat irrelevant.

Polling over the past decade has shown that solid majorities of Americans consider global warming real, and a significant threat, though few call it a top priority.

Now, given the slow progress in the Senate, some green groups say they want to broaden their appeal beyond committed environmentalists, to the skeptical, the agnostic and the distracted.

That means minimizing doomsday predictions and focusing on positives: A climate bill will create jobs in the renewable-energy industry and keep money away from oil-state villains.

A hard sell in Kansas?

On Tuesday night, climate activist Nancy Jackson addressed one of the most climate-skeptical audiences in the country: Kansans. She was speaking to college students in Manhattan — a town where one religious leader was able to draw congregants to screenings of “An Inconvenient Truth” only by passing out Nerf balls, so they could hurl them at the image of Al Gore.

“Take climate change off the table, OK?” Jackson said, after reciting evidence that the climate really is changing. “You don’t have to buy it for everything I’m about to say, because everything we do (to combat climate change) is a good idea for at least three other reasons.”

She told the students that Kansas has an abundance of wind, sun and crops such as corn and prairie grasses — all potential sources of renewable power. The message worked, at least on 21-year-old student Matthew Brandt. He said he doesn’t believe in climate change, but — after hearing Jackson’s talk — he was interested in windmills.

“I plan to have a wind turbine on my property” after graduation, Brandt said. “I figure it’s a good investment.”