A new UN report may signal the death knell for the Kyoto treaty by giving Russian treaty opponents the ammunition they've been looking for, according to a piece today by Paul Webster in Science (subscription required). The problem, according to Webster, is that previous UN calculations that seemed to show the Russians would have carbon credits to sell may be wrong, having failed to take into account burgeoning new Russian economic activity. Russia is key, because Kyoto doesn't come into effect until countries representing 55 percent of the world's carbon emissions sign on. With the U.S. out, as Webster and others note, Russia is pretty much the key. But the only way the Russians can win the political support internally is if Russia can make money selling carbon credits - essentially selling off its reductions in carbon use to other countries that want to use more (this carbon credit market is a central feature of Kyoto). If Russia doesn't have any to sell, political support there will likely evaporate.