Is the North Atlantic heat conveyor at risk of stopping due to climate change?
The “switching off” of the North Atlantic heat conveyor is a type of phenomenon listed as a low probability, high-risk event. An asteroid striking the Earth is another example. Other climate related examples include the loss of the Greenland and Antarctic Ice Sheets, major disruption of the El Nio, La Nia processes, as well as disruption to other ocean currents. These events are very unlikely, and most modelling groups cannot simulate any realistic scenarios which might lead to such events. However, if such events were to occur (and we do know they have happened in the past) then the consequences would be catastrophic. Therefore, in short, there is a chance of a catastrophic event of this type, but the risk is considered to be very small. They attract the attention of headline writers because a disaster makes better “news”. See Chapter 5 of the IPCC 4th Assessment Report (page 396 discusses some of these issues).
