A shift away from fossil fuels would make the United States a leader instead of a sometime rebel on energy and conservation issues worldwide, Mr. Gore said. Nor, he said, would the hard work of people who toil on oil rigs and deep in the earth be for naught. “We should guarantee good jobs in the fresh air and sunshine for any coal miner displaced by impacts on the coal industry,” he said by way of example. “Every single one of them.”

“Of course, there are those who will tell us that this can’t be done,” he conceded. “But even those who reap the profits of the carbon age have to recognize the inevitability of its demise. As one OPEC oil minister observed, ‘The Stone Age didn’t end because of a shortage of stones.’ ”