Are tipping points nearing in climate change?

A new study published in the journal "Atmospheric Chemistry and Physics" warns of possible "tipping points" that once passed, may cause a potentially uncontrollable surge in emissions of huge stores of greenhouse gases that are naturally stored in the earth's environment. The study's lead author is James Hansen, director of NASA's Goddard Institute for Space Studies in New York. Hansen reviewed the study for ABC News today, which is discussed here.

Scientists have been warning that tipping points are the greatest threat from human-induced global warming, making it potentially catastrophic to humanity. Vast releases of greenhouse gases have occurred in prehistory, drastically changing the planet. This will be the first time that anthropogenic causes risk cataclysmic change on Earth.