CURWOOD: It’s Living on Earth. I’m Steve Curwood.

GELLERMAN: And I’m Bruce Gellerman. The U.S. Senate has started work on what may be the best chance Congress has to cap the country’s greenhouse gas emissions. The bipartisan bill on global warming has momentum thanks to unexpected support from a senior Republican Senator: John Warner of Virginia.

CURWOOD: But his bill is taking heat from both sides: environmental activists say it doesn’t do enough to cut carbon in the atmosphere; industry argues it would push energy costs sky high. Living on Earth’s Jeff Young tells us about the climate change tug of war and the man in the middle.

YOUNG: Republican John Warner seems an unlikely champion of action on climate change. His home state of Virginia mines and burns a lot of coal. And Warner is often at odds with environmental groups when he votes for oil drilling offshore and in the Arctic Refuge. So why has the 80-year-old senator made global warming the top priority for his last year before retirement?

YOUNG: The ex-marine and former Navy secretary also sees a strong link between climate change and his first passion: national security. He’s partnered with Connecticut Independent Senator Joe Lieberman on a bill they call ‘America’s Climate Security Act.’ It’s similar to a bill Lieberman sponsored with Senator John McCain four years ago. But this one already has more support. In fact, Lieberman says, four of his cosponsors on this bill voted against the earlier one.

LIEBERMAN: So this thing is moving. And I think it’s moving in the right direction because we have answered in this bill some of the questions and concerns about the economic consequences.

LIEBERMAN: We create a steady glide path down and that’s going to be easier for the sources of emissions to deal with.

YOUNG: The Lieberman-Warner plan gives away some emissions credits in the early years. Roughly half would be free at first; the rest auctioned off. The bill also sets up an independent board with the power to provide more emissions credits if energy prices spark sharply. But Missouri Republican Kitt Bond doesn’t think that’s enough.

BOND: Families will face pain at the pump, higher home electricity and gas bills. Workers in energy-intensive sectors will face layoffs with their jobs going overseas to countries with lower energy costs. Hardest hit will be the weak and vulnerable with no extra room in their budget for higher energy costs. The poor, the fixed income will suffer.

O’DONNELL: Those permits or those allowances have an economic value. They are like giving them cash. It’s a giveaway that could potentially run into the billions, if not trillions of dollars of economic value to the worst polluters—the ones that actually got us into this global warming mess in the first place.

YOUNG: O’Donnell says this would repeat early mistakes made by the European Union when it set up a carbon-trading system that gave polluting companies billions in windfall profits without achieving the goals of emissions reductions. Environmentalists also say Senators Warner and Lieberman would not reduce greenhouse gases enough to avoid dangerous warming. The bill shoots for reductions somewhere between 50 and 60 percent by mid century. Vermont Independent Senator Bernie Sanders says that might be good politics, but not good policy.

SANDERS: You can have all the bargaining you want, you can have all the nonpartisanship you want, and yet this planet will face catastrophic damage unless we deal with the reality of the science.

YOUNG: Sanders cites recommendations from leaders of the Intergovernmental Panel on Climate Change, which recently shared the Nobel Peace Prize. They call for 80 percent reductions by the year 2050. Warner knew right away that his newfound interest in climate will make his last year in the Senate a stormy one.

WARNER: We have formulated a starting point for the Congress to assume its leadership. We’re off. We’re out of the starting gate.

YOUNG: For Living on Earth, I’m Jeff Young in Washington.