It seems there may be an emerging consensus at Copenhagen towards adopting the demands of the ATTAC movement and instituting a Tobin tax on international financial transactions in order to fund projects aimed at mitigating climate change. An optimist will see this as effectively killing two birds with one stone, curbing the excesses of “irrationally exuberant” financial markets in order to pay for urgently needed climate measures. A sceptic will point out that during a recession this was the only way to fund the largest example of dirigisme that has ever been needed by capitalist societies, and that a window of opportunity exists in which hitting the bankers is electorally harmless, something centre-right governments would never otherwise countenance. The sceptic will furthermore point out that there is no guarantee that all of this money will be used for the stated ends and not used, say, to lower national debt and so mollify the ratings agencies. Finally the sceptic will remind us that the plan in no way challenges the assumption that capitalism is compatible with environmental sustainability; on the contrary, it presents the former as guarantor of the latter. Business as usual, in other words.