By JOSH LEDERMAN and MATTHEW DALY
WASHINGTON (AP) -- President Barack Obama declared the debate over climate change and its causes obsolete Tuesday as he announced a wide-ranging plan to tackle pollution and prepare communities for global warming.
In a major speech at Georgetown University, Obama warned Americans of the deep and disastrous effects of climate change, urging them to take action before it's too late.
"As a president, as a father and as an American, I'm here to say we need to act," Obama said.
Obama announced he was directing his administration to launch the first-ever federal regulations on heat-trapping gases emitted by new and existing power plants -- "to put an end to the limitless dumping of carbon pollution."
Other aspects of the plan will boost renewable energy production on federal lands, increase efficiency standards and prepare communities to deal with higher temperatures.
Even before Obama unveiled his plan Tuesday, Republican critics in Congress were lambasting it as a job-killer that would threaten the economic recovery. Obama dismissed those critics, noting the same arguments have been used in the past when the U.S. has taken other steps to protect the environment.
"That's what they said every time," Obama said. "And every time, they've been wrong."
He touted America's strengths -- research, technology and innovation -- as factors that make the U.S. uniquely poised to take on the challenges of global warming.
Obama also offered a rare insight into his administration's deliberations on Keystone XL, an oil pipeline whose potential approval has sparked an intense fight between environmental activists and energy producers.
The White House has insisted the State Department is making the decision independently, but Obama said Tuesday he's instructing the department to approve it only if the project won't increase overall, net emissions of greenhouse gases.
"Allowing the Keystone pipeline to be built requires a finding that doing so would be in our nation's interests," Obama said. "Our national interest would be served only if this project does not significantly exacerbate the problem of carbon pollution."