President Obama is pressing again for passage of legislation that would confront the problem of global warming head-on.

Speaking in the Rose Garden of the White House, Obama said Washington must not miss the opportunity to work on cleaning the air and at the same time creating new "green" energy jobs. He called the measure "a jobs bill" and said the country for far too long has been too reliant on energy from fossil fuels.

The White House has seemed concerned that momentum for the bill is slipping away. Obama said "I know this is going to be a close vote because there is misinformation out there." He spoke as House Democratic leaders scurried to line up enough votes to get the bill passed there, possibly as early as Friday.

Republicans largely oppose the bill before House members, arguing that it amounts to a massive energy tax because it will force higher prices on electricity, gasoline and other energy sources as the economy shifts from cheaper fossil fuels, or companies and utilities are forced to buy pollution allowances.

House Speaker Nancy Pelosi, D-Calif., has scheduled a vote on the bill for Friday. While Democratic support has been growing, she is still believed to be short of the votes needed to get the bill through.

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The Senate, meanwhile, is waiting for the House to act. Approval of a climate bill in the Senate has been viewed as a long shot because it will require 60 votes to overcome a certain filibuster. And that has made a decision by some House Democrats to vote for the politically charged bill even harder.

The legislation would require the country to reduce carbon dioxide and other greenhouse gas emissions by 17 percent by 2020 and about 80 percent by the next century. To do that, electricity producers and industrial plants will have to make a dramatic shifthether corn ethanol is a climate-friendly fuel. Environmentalists have argued that corn ethanol emits more greenhouse gases than conventional gasoline if global land use changes as a result of greater corn demand are taken into account.

Those seeking greater commercial access to federal forests also won a prize in the last-minute negotiations. Inserted into the climate bill was an expanded definition of "biofuels" to include salvage lumber and brush from federal forests.

Rural electric cooperatives, who had argued they were being treated unfairly in the distribution of emission allowances, won an agreement to funnel more allowances their way.

And farmers were assured more favorable treatment in how so-called pollution "offsets" are managed. These are credits farmers can sell in exchange for planting trees or adopting practices that sequester carbon in the ground.

Rep. Collin Peterson, D-Minn., chairman of the House Agriculture Committee, said those and other changes turned him from one of the bill's sharpest critics to an advocate. "I think we'll be able to get the votes to pass this," said Peterson.

A new Washington Post-ABC News poll shows that three-quarters of Americans think the federal government should regulate the release of greenhouse gases, and 56 percent said they would approve such measures even if it increased their monthly electricity costs by $10.

"What we see is a job killer," Rep. Eric Cantor of Virginia, the second-ranking Republican in the House, said at a news conference Wednesday. "There's no question the cap-and-trade will cost millions of jobs" and higher energy prices.