Top NASA scientist James Hansen tried to warn the world, and in particular the U.S. Congress, over 20 years ago that the world was heading for disaster with global warming if something wasn’t done to curb the continued production of greenhouse gases. While many of the developed nations have done some things to slow down emissions, it hasn’t been enough and now with new nations like China and India bursting at the seams with growth and runaway use of unregulated fossil fuels, Hansen says time has nearly run out for the world.

Hansen told Congress just this week that the world has long passed the “dangerous level” for greenhouse gases in the atmosphere and needs to get back to 1988 levels and it needs to do so now and drastically.

He said that if left unchecked at current projections, the Earth’s atmosphere will only be able to keep the world from experiencing mass extinctions, dramatic rises in sea levels causing loss of coastal land masses and complete ecosystem collapse for another two more decades.

“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.”