Obama to lay out climate change plan in speech WASHINGTON (Reuters) - President Barack Obama said on Saturday that he will outline a climate change plan on Tuesday centered around reducing pollution from carbon emissions as he attempts to make good on a pledge for his second term. "This Tuesday, I'll lay out my vision for where I believe we need to go - a national plan to reduce carbon pollution, prepare our country for the impacts of climate change and lead global efforts to fight it," he said in a White House video. Obama made tackling climate change a top priority in his inaugural address in January when he began his second term. His speech will be at Georgetown University, the day before he goes on a three-nation tour of Africa. In his video message, Obama outlined what would be a major national effort to address climate change. He said scientists will be needed to design new fuels, farmers to grow them, engineers to devise new sources of energy and workers to build the foundation for a clean energy economy. There's no single step that can reverse the effects of climate change. But when it comes to the world we leave our children, we owe it to them to do what we can," he said. Sources familiar with his plans have said Obama is likely to roll out a number of measures on climate policy. They may include a strategy to limit greenhouse gas emissions from existing power plants, which account for roughly 40 percent of U.S. carbon dioxide emissions. Federal regulations are still pending on power plants that have yet to be built, after the Environmental Protection Agency missed an April deadline to roll out emissions rules. However, environmentalists have been pushing Obama's administration to go after a bigger target and set tighter standards for the roughly 1,400 coal-fired burners that already feed the nation's electric grid. The White House's top energy and climate adviser, Heather Zichal, said recently that Obama will take several steps to make tackling climate change a second-term priority. He is likely to talk about the importance of conserving energy, for example. Other steps he could announce include an expansion of energy efficiency standards for appliances and accelerate clean energy development on public lands. Another move could be to raise onshore oil and gas royalties, which was suggested by the administration earlier this year. Additional reporting by Patrick Rucker, Valerie Volcovici and Jeff Mason.; Editing by Eric Beech and Christopher Wilson