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WASHINGTON (AP) — Coastal states could veto offshore drilling plans under long-awaited legislation to curb global warming unveiled Wednesday.

The bill, sponsored by Sens. John Kerry, D-Mass., and Joe Lieberman, I-Conn., would allow states to opt out of federal drilling up to 75 miles from their shores, a concession to lawmakers concerned about offshore exploration in the wake of the Gulf Coast oil spill.

The measure also would allow states directly affected to veto drilling plans of nearby states if they could show that significant negative effects would result from an accident.

The legislation aims to cut by 2020 carbon dioxide and other heat-trapping greenhouse gases by 17 percent below 2005 levels and more than 80 percent by 2050. It also would set a price on carbon emissions for large polluters such as coal-fired power plants.

"We can finally tell the world that America is ready to take back our role as the world's clean energy leader," Kerry said at a news conference, surrounded by environmentalists and leaders from an array of energy companies.

"This is a bill for energy independence after a devastating oil spill, a bill to hold polluters accountable, a bill for billions of dollars to create the next generation of jobs and a bill to end America's addiction to foreign oil," Kerry said, calling stakes for the bill "sky high."

President Barack Obama hailed the measure, which has been in the works for months.

"The challenges we face — underscored by the immense tragedy in the Gulf of Mexico — are reason to redouble our efforts to reform our nation's energy policies," Obama said in a statement. "For too long, Washington has kicked this challenge to the next generation."

Despite the lofty rhetoric, the measure faces bleak prospects in the Senate amid partisan disputes over the drilling provision and other issues, including immigration reform.

South Carolina Sen. Lindsey Graham, who had been the bill's only Republican backer, withdrew his support last week, saying it is impossible to pass the legislation in the current political climate.

Graham issued a statement Wednesday offering tepid encouragement.

"I believe the broad concepts we came up with before (Graham withdrew) are transformational and are the most consumer- and business-friendly effort to date in dealing with carbon pollution" Graham said.

Most importantly, he added, the bill "can serve as a framework in allowing America to lead in the creation of alternative energy jobs and significantly reducing our dependency on foreign oil. With these goals in mind, I am interested in carefully reviewing the details of the new proposal."

The 1,000-page bill, tweaked in recent days in response to the Gulf spill, requires an Interior Department study to determine whether states could be economically and environmentally affected by a leak from an offshore drilling rig.

States that can demonstrate significant negative effects could pass a law opposing a specific project.

States that go ahead with offshore drilling would retain 37.5 percent of the federal revenue generated — a shift from current policy. Now royalty revenue goes to the Treasury; states collect no royalties.

Senators in Western states are likely to oppose the change, saying offshore revenue belongs to the nation as a whole. But coastal states argue that when an accident occurs, they're the ones affected by cleanup costs.