For some time, the received wisdom has been that a post-Bush administration will herald a new era in which the world can move boldly forward on climate change. But as the presidential elections draw close, the political climate for taking strong action to reign in greenhouse gases is increasingly shaky.

Whether Democrat Barack Obama or Republican John McCain wins the White House next month, the elected president will face a daunting list of challenges in making climate change a priority both on the home front and internationally. As reported in our special package of News Features in this issue (page 126), not least of these will be the short lead-in to negotiating a successor to the Kyoto Protocol at the same time as pushing federal legislation through Congress.

Although both candidates made climate change a signature issue early on in their campaigns, McCain's choice of Alaska governor Sarah Palin as vice-presidential nominee weakens the Republican message. Having publicly questioned the contribution of human activity to climate change and championed aggressive offshore drilling, Palin positions her politics to the right of the existing administration (Washington Post 23 September 2008, A04), casting doubts on whether a McCain–Palin administration would carve out a new direction for the Republicans.

Arguably of graver concern, however, is the escalating financial crisis, which is reverberating worldwide and, teamed with rocketing fuel prices and insecure energy supplies, could push rising emissions far down the political agenda regardless of who is in office. Indeed, both presidential candidates have already had to pull back from positions held early on in the election. As oil prices soared to over $140 a barrel earlier this year, McCain and Obama were forced to rethink their opposition to offshore oil drilling, though Obama has done so a lot more cautiously than his opponent.

Now the government's proposed $700-billion scheme to rescue Wall Street from free-falling will leave the president-elect with little money in the coffers for spending elsewhere. With a bail-out that could push the US budget deficit above $1,000 billion, Obama's ambitious plan to invest $150 billion over ten years in renewable energy (page 127) may have to be phased in, should he win the White House (Financial Times 24 September 2008). Similarly, McCain's commitment to spending $2 billion annually on clean-coal technologies may have to go on the back burner. And with the average American family feeling the credit crunch in their pockets, less popular still will be any measures that increase energy costs.

Yet climate change won't slow with the global economy, making it imperative that the post-Bush administration rise to the challenge of setting a high priority on climate policy, regardless of what obstacles stand in the way.