Question: If global warming happens will the world freeze (alike the movie "The day after tomorrow")? If yes, how can we prevent this from happening?

Daniel Parsons answered on 10 Nov 2014:

Great question. What is clear is that the world is warming. The Intergovernmental Panel on Climate Change (IPCC), which is a group of leading scientists from across the world agree, in their recent assessment report, that the world will warm by around 2 degrees. Now this will have all sort of effects, the most important been how it will change the distribution of water across the planet – in general the predictions show that dry areas get drier and wet areas get wetter, which is very important for water security of some of the most vulnerable people on earth. In terms of the world freezing over as a result of this: that is very unlikely. But we could get much colder here in the UK during winter. We are kept warm in winter by the Atlantic ocean currents, called the Gulf Stream, that brings warm (and wet!) air North from the equator during our winters – keeping us warmer than we would be most of the time. Now one of the predictions as a result of a warming world due to climate change is that this warm Gulf Stream current will slow down or even stop and if it does then we in the UK will get much colder in winter. For example, the town of Churchill in Canada is about the same distance North of the equator as London, their winters are very cold and even Polar Bears visit! The only reason we are not as cold as that in winter is the effect the Atlantic Ocean and Gulf Stream has on our climate!