When President Obama took office in January, many opponents of environmental destruction breathed a sigh of relief. Not only would George W. Bush leave office, but his equally unpopular vice president, Dick Cheney, would step down, too. The former CEO of Halliburton, the world's largest field oil services company, received a League of Conservation Voters score of zero for his last term as Wyoming's congressman. In contrast, his replacement as VP, Joe Biden, had a lifetime score of 86 in 2006. What are the differences behind the numbers?

Both in and out of public office, Cheney has a long history of favoring the oil industry regardless of environmental cost. Shortly after becoming vice president, he was asked to chair the president's new National Energy Policy Development Group (aka Energy Task Force), which was widely criticized for operating with little transparency, keeping the names of those who attended meetings secret, and seeming to be overly influenced by corporate oil interests.

"Six years later, we see we lost an opportunity to become less dependent on importing oil, on using fossil fuels, which have been a threat to our national security and the well-being of the planet," said U.S. Rep. Henry Waxman in 2007, upon seeing the Washington Post's report that Task Force meetings were made up of oil executives, a fact the Bush administration had fought to keep secret. In 2005, Cheney successfully urged Congress to exempt hydraulic fracturing — a drilling technique developed by Halliburton — from the Safe Drinking Water Act, a move that allowed companies to legally introduce known hazardous chemicals to underground drinking water supplies.

While Biden hasn't been in the veep seat for long, his Senate record stands in marked contrast to Cheney's. He has generally come down on the side of environmental protection, though his stances are well within the political mainstream. He has opposed Arctic oil drilling (Cheney supports it), favors a cap-and-trade system for greenhouses gases (Cheney opposes it) and co-sponsored the Global Warming Reduction Act and the Fuel Economy Reform Act. Biden supports a clean energy standard, which would oblige utility companies to produce 20 percent of their electricity from clean sources by 2020.

While Biden was recently put in charge of Obama's nuclear nonproliferation agenda, and will try to get Congress to ratify the Comprehensive Nuclear Test Ban Treaty, he is open to nuclear power as a viable energy source. Cheney's stance is a bit more definitive — he has long trumpeted nuclear power as the solution to global warming, favoring increased production as a long-term energy strategy rather than enforcing limits on carbon emissions or other such regulations. As he told Chris Matthews in 2001, "If you're really serious about greenhouse gases ... let's take another look at nuclear power, use that to generate electricity without having any adverse consequences.''

Just as Cheney's record has largely favored the interests of oil and business, Biden's has supported moderate environmental legislation, giving him the clear edge as the greener VP. The real question is not only whether the measures proposed by Biden will be put into practice, but if they will be enough to shift our course away from ecocide.