California takes lead in global warming fight

LOS ANGELES (Reuters) - California catapulted to the forefront of U.S. efforts to fight global warming on Wednesday with an accord that will give the state the toughest laws in the nation on cutting greenhouse gas emissions and possibly spur a reluctant Washington to take similar action. WASHINGTON (Reuters) - Earth's protective ozone layer, which was notably thinning in 1980, may be fully recovered by mid-century, climate scientists said on Wednesday. LONDON (Reuters) - Teams of international scientists have used observations from NASA's Swift satellite and other telescopes to witness the evolution of a cosmic blast into a stellar explosion or supernova.