Who's the greenest of them all?

New Scientist
Saturday 1/3/2008 Page: 8

If the election rested on green credentials alone, the identity of the next US president might surprise you.

CLIMATE change is the biggest science issue in the world, and the biggest science issue in the upcoming US election. Who is the front runner? If you look at the parties, it's a no-brainer: the Democrats snatched control of both houses of Congress in 2006, and have so far made good on their promises to fight climate change. The Republicans under George W. Bush have a lousy record.

Nonetheless, the stakes couldn't be higher for the next president to commit to combating global warming. For one thing, the country still doesn't have a federal mandate to cap carbon emissions. Among the three leading candidates, you might assume that one of the Democrats - either Hillary Clinton or Barack Obama, is the most environmentally friendly. Both senators have made big promises to cuts emissions and fund clean energy research. Republican front runner John McCain has a set of climate credentials that arguably eclipses them both. He has railed against inaction on the issue since long before it was fashionable to do so.

Now that he's the presumptive conservative nominee, however, there are signs that the Arizona senator will backtrack. There is also an independent candidate, Ralph Nader, who supports a carbon tax - a fee charged for every tonne of carbon emitted - rather than a cap-and-trade system. That stance is widely considered politically untenable, and Nader got less than 0.4 per cent of the vote in 2004. So of the three main candidates, who is the greenest?

On the Democratic side, both Clinton and Obama are bolstered by their party's record. Last December the Democrats pushed through the Energy Independence and Security Act, requiring all can in the US to run for at least 35 miles on every gallon of gasoline by 2020. Several bills are also circulating that call for emissions cuts as deep as 8o per cent from 199o levels by 2050. If elected president, both candidates say they will work to make one of these bills law.

Whether any of those plans will actually work remains to be seen, says John Holdren, chair of the American Association for the Advancement of Science. "Eighty per cent by 2050 is almost a theological argument. No one can know what the world will be like in 42 years," he says. "The important thing is that we get on a track to make deep cuts in emissions down the road." To do that, Holdren and other climate experts agree that by itself a cap-and-trade system is not enough.

Large funding increases for clean energy research and development are needed, as are improvements to energy efficiency across the board. Clinton and Obama have each promised to invest $150 billion over to years to commercialise clean energy technologies, and to double basic science research into clean energy and efficiency measures. Both claim they will ensure at least 25 per cent of US energy comes from renewable sources by 2025, and both have promised to raise fuel efficiency standards for cars. Both support legislation that would sanction auctioning the full allotment of carbon credits to greenhouse gas emitters. That would maximise funds that could then be used to develop clean energy technologies.

However, the candidates do have subtle differences in their senate records, with Clinton edging ahead. For instance, last year Obama raised concerns among environmentalists when he co-sponsored a bill that would promote the development of coal-to-liquid fuel technologies - essentially turning coal into a source of diesel fuel. Clinton, on the other hand, introduced the Zero-Emissions Building Act of 2007, which aims to make all new federal buildings carbon-neutral by 2030. As the race for the Democratic nomination goes to the wire, the votes of the science-savvy super-delegates could be vital.

Of the three then, who is best placed to implement an aggressive policy to curtail global warming? The surprising answer may be McCain. Clinton and Obama's big promises could bring other large emitters like China and India into line behind the US. That's important, especially as world leaders look to a new climate policy after the Kyoto Protocol expires in 2012. But McCain is the only candidate battle-hardened by years of defending his climate change bills on the Senate floor.

As early as 2000 he refused to toe the party line, calling climate change "a very serious business." In 2003 he and Senator Joseph Lieberman of Connecticut sponsored the first iteration of the Climate Stewardship Act, which would have limited US emissions to 2000 levels by 2010. It was defeated, but McCain's revisions kept surfacing in the Senate, complete with more stringent emissions targets. Last year he reintroduced the bill as the Climate Stewardship and Innovation Act of 2007. It calls for a nationwide cap-and-trade system as well as funding for clean technology that would allow the country to cut greenhouse gas emissions to 6o per cent of 1990 levels by 2050.

Some of the bills now in Congress are tougher, but McCain's history of pioneering advocacy for regulations is undeniable. The question is whether his stance has weakened. In December, he was the only senator absent for a crucial vote on the Energy Independence and Security Act. At stake was an amendment that would require the US to get 15 per cent of its energy from renewable sources by 2020. The bill failed by one vote and the amendment was stripped out of the version that ultimately passed into law. McCain's message on the campaign trail has also weakened.

"Now he's using words very carefully and qualifying his statements. It suggests to me he's trying to open up some flexibility on climate change," says Neal Lane, former director of the White House Office of Science and Technology Policy. However, McCain is unlikely to beat a full retreat to the old Republican line, says Sherwood Boehlert, a Republican and former chair of "Clinton and Obama's big promises could bring other large emitters like China and India into line behind the US" the House of Representatives science committee.

In short then, McCain has the greenest credentials; the Democrats the greenest promises. And any will be greener than the current president. "Any of the three candidates would embrace serious climate change legislation," says Holdren. If he's right, a major climate bill - likely the Lieberman-Warner bill that passed through the Senate in December - could be signed into law in early 2009. Just as important will be the next president's role in maintaining a long-term commitment, says Holdren. "Whoever it is, he or she will have a great opportunity - and responsibility - to get us on the right track."