The Obama administration is preparing to unveil what it calls a major initiative on tackling climate change. The White House says President Obama will soon announce the first limits on greenhouse gas emissions from new and existing power plants. At his speech Wednesday in Berlin, President Obama pledged action on global warming.

President Obama: “The effort to slow climate change requires bold action. And on this, Germany and Europe have led. In the United States, we have recently doubled our renewable energy from clean sources like wind and solar power. We’re doubling fuel efficiency on our cars. Our dangerous carbon emissions have come down. But we know we have to do more. And we will do more.”

At a public event in Washington, the White House coordinator for energy and climate change, Heather Zichal, said Obama will impose the new emissions limits through Environmental Protection Agency authority under the Clean Air Act. The move would not require congressional approval, meaning Obama could bypass expected Republican-led opposition. Describing Obama’s approach to global warming, Zichal said: “He is serious about making it a second-term priority. He knows this is a legacy issue.”