WASHINGTON — Exactly 20 years after warning America about global warming, a top NASA scientist said the situation has gotten so bad that the world’s only hope is drastic action. James Hansen told Congress on Monday that the world has long passed the ‘dangerous level’ for greenhouse gases in the atmosphere and needs to get back to 1988 levels. He said Earth’s atmosphere can only stay this loaded with man-made carbon dioxide for a couple more decades without changes such as mass extinction, ecosystem collapse and dramatic sea level rises. ‘We’re toast if we don’t get on a very different path,’ Hansen, director of the Goddard Institute of Space Sciences who is sometimes called the godfather of global warming science, told The Associated Press. ‘This is the last chance.’ Hansen brought global warming home to the public in June 1988 during a Washington heat wave, telling a Senate hearing that global warming was already here. To mark the anniversary, he testified before the House Select Committee on Energy Independence and Global Warming where he was called a prophet, and addressed a luncheon at the National Press Club where he was called a hero by former Sen. Tim […]