LONDON — 2007 was the year in which global warming finally began to be taken seriously. Climate-change deniers were in full retreat, and the realization that we face a long and grave crisis was finally dawning on the general public. However, it remains to be seen whether the world will agree on effective measures to deal with the crisis.

The global conference in Bali that was supposed to kick off negotiations for a new treaty to replace the Kyoto accord after 2012 ended ambiguously. The American delegation did not succeed in wrecking it, but it did manage to get all specific targets for cuts in greenhouse gas emissions removed from the text of the agreement.

The other countries went along with it in order to stop the United States from walking out, on the assumption that next year's presidential election will produce an administration that is willing to cooperate. Then the hard targets for cuts will get put back in, and the U.S. presumably will sign up to them, and the Indians and the Chinese and the other big developing countries will make a deal that commits them to some cap on emissions in return for much technological and financial help from the developed countries in installing clean energy technologies.