Global Warming Tipping Points?

One of the hottest controversies among global-warming watchers these days is whether or not global warming will ever pass a “tipping point”, setting off rapid, unstoppable, and catastrophic climate change. Do climate tipping points even exist? Or will climate change just continue slowly and inexorably for hundreds or perhaps even thousands of years?

No one knows for sure. But well-meaning climate scientists who believe in tipping points warn of doomsday scenarios in an effort to get people to do something about global warming before it is too late. You’ve heard it all before - the Amazon rainforest will become grasslands; the polar ice caps will melt; the seas will rise several meters, flooding most of Earth’s populated areas; ecosystems will be disrupted. Some climate scientists worry that talk of tipping points could backfire. If a tipping point doesn’t happen within the next couple of decades, will people quit worrying about global warming altogether and decide it’s not worth doing anything about? Yawn! I’m bored with this whole subject…….

The best climate models can’t tell us yet whether or not there are tipping points. And therein lies the danger - there may actually be tipping points. Perhaps more likely is that lots of little tipping points in Earth’s complex climate system will add up to acceleration of global warming the higher the temperatures get.

For a recent news article on the subject, see “Among Climate Scientists, a Dispute Over ‘Tipping Points’”, The New York Times, Mar. 29, 2009.