January 8, 2017, by Tim Radford
New research forecasts much colder weather in northern Europe if rising CO2 emissions continue to impact on the Atlantic ocean current.
LONDON, 8 January, 2017 – Here is the long-term weather forecast for the North Atlantic, in a world in which carbon dioxide concentrations in the atmosphere double: a powerful ocean current called the Atlantic Meridional Overturning Circulation (AMOC) will continue to weaken, and then collapse.
This is the ocean current that takes tropic heat northward, and then grows cold, dives to the ocean floor, and runs southward. And it is the current that delivers the heat that, for example, keeps the British Isles 5°C warmer than their latitude might dictate.
Carbon dioxide absorbs heat reflected from the rocks. And the more carbon dioxide in the atmosphere, the warmer the planet will become.
For two centuries, humans have been burning fossil fuels and putting ancient carbon back into the atmosphere. The average planetary temperatures, so far, have climbed about 1°C.
If CO2 levels double, temperatures will climb a lot higher. For the first 300 years after the carbon dioxide doubling, nothing much will happen. But then there will be a sweeping drop in temperatures over the north Atlantic.