Early in his career, a scientist named Mario J. Molina was pulled into seemingly obscure research about strange chemicals being spewed into the atmosphere. Within a year, he had helped discover a global environmental emergency, work that would ultimately win a Nobel Prize.
Now, at 70, Dr. Molina is trying to awaken the public to an even bigger risk. He spearheaded a committee of the American Association for the Advancement of Science, the world’s largest general scientific society, which released a stark report Tuesday on global warming.
The report warns that the effects of human emissions of heat-trapping gases are already being felt, that the ultimate consequences could be dire, and that the window to do something about it is closing.