Environmentalists and representatives of Arctic indigenous cultures said the science was clear enough to justify stronger actions to stem gases linked to the changes.

With no clear goal, smokestack and tailpipe emissions of gases linked to rising temperatures relentlessly climbed.

The most obvious recent example is California's ambitious proposal to require automakers to cut emissions of carbon dioxide and other gases linked to global warming.

The bill failed in large part because of objections by Democrats who favored including caps on carbon dioxide, a heat-trapping gas linked to global warming.

But such plants would also be among the country's most potent producers of carbon dioxide, the king of gases linked to global warming.

It could also result, however, in building more coal-fired plants, which emit carbon dioxide, a gas linked to global warming.

Administration officials announced several modest agreements with a number of industries today for voluntary controls on emissions of gases linked to global warming.

Automakers have been increasingly alarmed by public attention to carbon dioxide, a gas linked to global warming.

Besides contributing to smog, methane is a heat-trapping gas linked to global warming.

Vehicle emissions contribute to the increasing concentration of gases linked to climate change.