Washington ? As President Barack Obama prepares to attend a world summit on climate change, a majority of Americans are willing to pay more for a solution only if it would create “green” jobs in the United States, according to a McClatchy-Ipsos poll released Wednesday.

Take away the benefit of new jobs, and the willingness to pay a little more on their monthly electric or other bills drops.

Just half the country is willing to pay higher prices to cut the emissions of greenhouse gases if it doesn’t also create jobs, and that slender support turns into outright opposition if the price rises from $10 a month to $25 a month.

“A substantial majority believes that climate change is happening, that global temperatures are rising and that it’s mostly because of human activity,” said Michael Gross, the vice president of Ipsos Public Affairs, which conducted the poll.

A solid majority of Americans, 70 percent, thinks that global warming is real, though a sizable minority, 28 percent, says it isn’t.

Similarly, 61 percent think that it’s happening because of the burning of fossil fuels, while 34 percent say it’s mostly a natural phenomenon.

Americans are closely divided on the proposed solution pending in Congress, a “cap-and-trade” system aimed at cutting U.S. emissions of greenhouse gases from smokestacks and tailpipes.

“There isn’t any overwhelming support or opposition for cap and trade now,” Gross said.

The poll found that 52 percent of Americans support the legislation, which has passed the House of Representatives but is stalled in the Senate. Forty-one percent oppose the measure.

A solid majority, 69 percent, said they’d support it even if it cost them $10 a month if it created a “significant” number of American jobs. Twenty-nine percent said they’d still oppose the legislation under those circumstances.

That majority support dropped to 60 percent if the costs rose to $25 a month, and opposition rose to 36 percent.

How much the legislation would cost is a subject of debate among partisans. The nonpartisan Congressional Budget Office said it would cost the average U.S. household $90 a year in lost purchasing power in 2012, rising to $925 a year by 2050.

Whether it would create or kill jobs also is heavily debated. The CBO said it would “probably have only a small effect on total employment in the long run.”

Public support for the cap-and-trade legislation drops if there’s no promise of green jobs to offset the costs, the poll found.

Given the prospect of paying $10 a month more on their electric bills but with no mention of jobs, 50 percent said they’d support it and 48 percent said they’d oppose it.

Given legislation that would raise their bills by $25 a month, again with no mention of jobs, 55 percent opposed it, while 43 percent supported it.

The poll had a margin of error of plus or minus 2.93 percentage points.