Lisa P. Jackson is stepping down as administrator of the Environmental Protection Agency after a four-year tenure that began with high hopes of sweeping action to address climate change.
"Under her leadership, the E.P.A. has taken sensible and important steps to protect the air we breathe and the water we drink, including implementing the first national standard for harmful mercury pollution, taking important action to combat climate change under the Clean Air Act, and playing a key role in establishing historic fuel economy standards that will save the average American family thousands of dollars at the pump, while also slashing carbon pollution."
Ms. Jackson's departure comes as many in the environmental movement are questioning Mr. Obama's commitment to dealing with climate change and other environmental problems. After his re-election, and a campaign in which global warming was barely mentioned by either candidate, Mr. Obama said that his first priority would be jobs and the economy and that he intended only to foster a "conversation" on climate change in the coming months.
That ambivalence is a far cry from the hopes that accompanied his early months in office, when he identified climate change as one of humanity's defining challenges.