WASHINGTON -- As a pair of senators introduced their long-awaited climate-change legislation yesterday to a cheering crowd on the front lawn of the Capitol, Pennsylvania's senatorial delegation said it is not yet on board with the effort.

Sens. Arlen Specter and Bob Casey, both Democrats, yesterday said the bill doesn't address their concerns about coal and other Pennsylvania industries that could be harmed by cap-and-trade legislation. Combined with a stiff Republican front, any Democratic defections would be enough to kill legislation in a chamber where 60 votes are needed to avoid a filibuster.

The Clean Energy Jobs and American Power Act, introduced by Sens. Barbara Boxer, D-Calif., and John Kerry, D-Mass., imposes tougher greenhouse-gas emissions reductions than its House counterpart, a bill that squeaked through in June. It mandates a 20 percent reduction in greenhouse gases by 2020 and an 83 percent reduction by 2050.

Ms. Boxer boasted of a stronger coalition of business interests on board with the Senate bill. It does make more concessions to industry by providing funding and incentives for carbon capture and storage technology, natural gas and nuclear power. The bill also leaves a crucial question open for debate: how to allocate emissions permits, which constitute the basis for the cap-and-trade market.

Mr. Kerry and Ms. Boxer touted the bill as a deficit-neutral mechanism to create so-called green jobs -- which they estimated at 2 million nationwide -- while reducing funding for America's enemies through oil profits, in addition to environmental gains.

They were joined by 10 other senators at the rally, but not by Mr. Casey or Mr. Specter. A spokeswoman for Mr. Specter -- who sits on the Environment and Public Works Committee, which will weigh the bill -- said the senator had planned on attending, but that the event conflicted with a National Institutes of Health funding announcement in Maryland that also drew President Barack Obama.

Mr. Specter issued a statement expressing his general support for fighting climate change "in a way that is economically responsible, environmentally effective and encourages action by other countries to achieve these goals."

But he listed a few provisions in the bill that he feels need to be strengthened during his committee's deliberations, including more funding for carbon capture and sequestration (the bill now provides $10 billion) and more protection for steel and other heavy industry against foreign competition.

Ms. Boxer read Mr. Specter's positive statement to the crowd and noted that he wanted some changes, adding: "It's very technical. But that's Arlen -- he's thorough."

Mr. Casey said in an interview, "I can't count myself as a 'no' yet, but we're trying to work through some of these issues." He said he still must analyze the entire bill, but he'd like to see more help for the coal industry, in addition to protections for workers who might lose their jobs as industries shed payroll to pay for carbon permits. As for an emissions caps, Mr. Casey said he'd prefer the 17 percent reduction by 2020 that the House bill calls for.

It has been tough to wrangle into the cap-and-trade fold Democrats from manufacturing states, including Pennsylvania's Rep. Jason Altmire, D-McCandless, who voted against the bill in the House. Sen. Jay Rockefeller, D-W.Va., issued a statement yesterday saying he couldn't vote for the Kerry-Boxer bill until he sees more help for the coal industry.

And that's just from the left side of the aisle.

A group of Republican senators held a news conference blasting the bill as a job-killer and called it "the largest tax increase in American history," in the words of Sen. James Inhofe, R-Okla. The Republicans said they would rather invest money in efficiency and alternative energy, while also exploring more domestic fossil fuels through offshore drilling and other means.

Republicans don't want emissions caps and a market for the right to pollute because, they said, utility companies will just pass on those costs to consumers at a time when they can ill afford it.

Still, Mr. Kerry said he has not given up on the minority party. "I'm convinced there are a number of Republicans who want to get this over the finish line, and we're going to continue to work with them," he said after the rally, in which no Republicans participated.

Some business interests have sided with the legislation, arguing that if no bill passes, the Environmental Protection Agency could impose harsher -- and more unpredictable -- restrictions under the Clean Air Act. EPA Administrator Lisa Jackson yesterday took a step in that direction, announcing a proposed rule to force large polluters to obtain permits which show that they are using the best technologies and energy-efficiency measures to control pollution.

"We can begin reducing emissions from the nation's largest greenhouse gas emitting facilities without placing an undue burden on the businesses that make up the vast majority of our economy," Ms. Jackson said. "We know the corner coffee shop is no place to look for meaningful carbon reductions."

Much of the rhetoric in favor of climate-change legislation involves casting the United States as a leader in reducing greenhouse gases, to prod other nations to do the same. Many environmental groups are pressing to have a final bill before December's climate-change summit in Copenhagen.

Mr. Kerry said he's optimistic that his climate bill, as well as the controversial healthcare legislation, can pass before then, but he said a successful Copenhagen summit doesn't depend on it.

"I've talked to all of the [environmentally concerned global] leaders," he said. "They are pretty much in agreement that if we are moving in a serious way, if we are showing our good faith here, the president is supportive of it and we're simply stalled by virtue of time on the floor, that's not going to have a negative impact. The seriousness of purpose is what's going to be measured.

"Clearly, it's better to have it [the legislation] done, because the signal is more direct and clear, and our hope is to be there. But I don't want to get locked into something that we don't have control over."

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