Tierr@_de_N@die: We thought that the temperature rising occurs gently , as far as the CO2 concentration also rises due to our activity. Now lot of scientist believe that an abrupt transition could happen. The reason: the Gulf Stream.
This forced a paradigm shift in how scientists thought about climate change. Earlier, they had tended to imagine creeping shifts occurring over many millennia. But by the late 1990s, they accepted that abrupt transitions, tipping points, could occur.
Source (nytimes.com): In the Atlantic Ocean, Subtle Shifts Hint at Dramatic Dangers