six-plus wasted years
There are ideas kicking around in Congress among both Democrats and Republicans to put a tax on carbon emissions, or at least to set up a cap-and-trade system where emissions are limited and the right to emit can be bought and sold.
Either - or better yet, both - would be a good start. And hopefully Congress can act sooner, while there is still occasionally ice in the Arctic. But there is no reason to expect the de facto Bush Administration will actually go along with anything. Despite his call for a climate change conference and alleged support for the UN process, the Bush Administration is STILL, despite all the evidence, working against any meaningful action on curbing emissions. For example, Bush's Transportation Department has been working to gin up opposition to a California plan to slash emissions caused by cars and trucks.
Not only does the Bush EPA refuse to treat greenhouse gases as pollutants under the terms of the Clean Air Act (have they actually started doing so since the courts ruled against them?), they actively try to STOP efforts like the one in California to do something positive.
No matter how bad Iraq gets, I really think his inaction - worse, his prevention of action - on climate change at a crucial time will be the most-reviled element of Bush's so-called legacy.