Mr. Obama’s path on global warming is a case study in his evolving sense of the limits of his power and his increased willingness to work around intense conservative opposition rather than seek compromise. After coming to office four years ago on a pledge to heal the planet and turn back the rise of the seas, he is proceeding cautiously this time, Democrats said, intent on making sure his approach is vetted politically, economically and technologically so as not to risk missing what many environmental advocates say could be the last best chance for years to address the problem.
The centerpiece will be action by the Environmental Protection Agency to clamp down further on emissions from coal-burning power plants under regulations still being drafted — and likely to draw legal challenges.
The administration plans to supplement that step by adopting new energy efficiency standards for home appliances and buildings, a seemingly small advance that can have a substantial impact by reducing demand for electricity. Those standards would echo the sharp increase in fuel economy that the administration required from automakers in the first term.