The Republicans

McCain: Senator John McCain was championing the cause of climate change long before it jumped party lines and became a centre-stage issue. Early on, McCain bucked his party's lukewarm stance on global warming, co-sponsoring the 2003 McCain-Lieberman Climate Stewardship Act, the first Senate bill calling for mandatory greenhouse gas reductions. In recent years he has proposed various iterations of the original bill, but more aggressive climate proposals circulating through Congress have since overshadowed his. Once opposed to offshore drilling, McCain changed his mind on the issue earlier this year under pressure from record-high fuel prices and a push to reduce foreign dependence on oil. McCain has come out aggressively in favour of expanding domestic oil and gas exploration and production, even hinting that his long-held opposition to drilling in the Arctic National Wildlife Refuge (ANWR), a region in northeastern Alaska, could soon change. Perhaps a forewarning of that, McCain supporters now routinely chant the mantra “Drill, baby, drill” at McCain campaign rallies.

Palin: For a presidential candidate who long ago made climate change one of his signature issues, McCain's choice of a vice presidential running mate, Alaskan governor Sarah Palin, introduces an ambiguous message to the Republican ticket when it comes to climate and energy policy. Palin has publicly questioned whether climate change has any manmade influence, only recently softening her wording on the issue by ceding that human activities “can be contributing” to it. Palin has long been in favour of drilling in the ANWR, and in her first live interview since accepting the Republican nomination for vice president, Palin said that for now she and McCain would “agree to disagree” on drilling in the ANWR. “I think, eventually, we're all gonna come together on that one,” said Palin. She has sued the federal government to block the recent listing of polar bears as threatened by climate change, for fear that it would stand in the way of drilling ambitions.

The Democrats

Obama: Senator Barack Obama takes a hard line on climate and energy policy, calling for the United States to step up to a leadership role in international climate negotiations. Obama supports an 80 per cent reduction of greenhouse gas emissions below 1990 levels by 2050, which he proposes to accomplish through a 100 per cent auction-based cap-and-trade scheme to make polluters pay for their carbon dioxide emissions. He plans to funnel the expected $7 trillion revenue stream to fund the transition to a clean-energy economy. Obama was initially in favour of the federal moratorium on offshore oil drilling but recently made a qualified turn-around on the issue, agreeing to a compromise package that would allow for limited offshore drilling. In January, Obama came under fire from environmentalists when he co-sponsored legislation on coal-to-liquid fuel production, but he has since clarified his position by saying that he wouldn't support this technology unless it emitted at least 20 per cent less lifecycle carbon than conventional fuels.

Biden: A longtime advocate for US leadership on climate change, Joe Biden was the only senator to initially vote against the 1997 Byrd-Hagel Resolution, which asserted that the United States should not agree to mandatory greenhouse gas reductions unless developing countries meet similar requirements. Ultimately, it sounded the death knell for US adoption of the Kyoto Protocol. From his post on the Senate Foreign Relations Committee, he asked that his vote be recorded as a “No”, but was eventually persuaded by his party to support the unanimous resolution. In 2005, Biden co-sponsored a Senate resolution to re-engage the United States in international climate negotiations and to put the nation “back on the right side of history”. He also co-sponsors the toothiest climate bill in the Senate, the 2007 Boxer-Sanders Global Warming Pollution Reduction Act, which calls for US reductions in greenhouse gas emissions to 80 per cent below 1990 levels by 2050.

US Elections, see related article doi:10.1038/climate.2008.100

US Elections, see related article doi:10.1038/climate.2008.102