Obama issues challenge on climate change with power plant rule

U.S. President Barack Obama delivers remarks on the Clean Power Plan at the White House in Washington August 3, 2015. REUTERS/Jonathan Ernst

WASHINGTON (Reuters) - President Barack Obama challenged America and the world to step up efforts to fight global warming on Monday at the formal unveiling of his administration's controversial, ramped-up plan to cut carbon emissions from U.S. power plants.

Declaring climate change the greatest threat facing the world, Obama said the regulation requiring the power sector to cut its emissions by 32 percent from 2005 levels by 2030 would reduce Americans' energy bills and improve the health of vulnerable populations nationwide.