James Hansen warned the world in the 1980s that global warming was coming. Now, he is warning that it is barreling down even faster than expected.

Three decades after Hansen first warned Congress about global warming, the overwhelming scientific consensus is that he was right—and most would say that far too little has been done to address the threat.

Sea level rise from melting ice sheets in Antarctica and Greenland threatens catastrophe for coastal cities within decades unless strong measures are taken to reduce CO2 emissions from the use of fossil fuels, argues climate scientist James Hansen.

If you wanted to get a sense of the State of the Planet, you didn’t need to be at the Columbia University conference on Oct. 11. You just needed to follow #SOP2012. Six hundred people gathered at the event to think about the future of sustainable development, while 476 people sent 1,300 tweets, making about 6.2 million impressions through Twitter. And one thread running through the event was that social media is an important way to draw attention to sustainable development issues on an international platform and in a comprehensible way.

This year’s Midwest heat wave and some other recent extreme weather events are no fluke of nature, but a consequence of a warming planet, according to an analysis of climate data by NASA scientists.