New research suggests the crop production in the UK is set to drop drastically if climate change triggers the collapse of the vital ocean’s current pattern.
What is known as the Atlantic Meridional Overturning Circulation (AMOC), an integrated component of surfaces and deep currents, pushes heat over to UK from the tropics. The AMOC makes the UK far warmer and wetter than it would be otherwise.
Scientist from the University of Exeter conducted a study demonstrating that while warming climates in the UK is expected to boost food production, the possible collapse of the AMOC would cause the “widespread cessation of arable (crop-growing) farming.”
A collapse of this kind would leave the UK much cooler than before. The collapse of the AMOC would also make the UK much drier and unsuitable for crop growth, this would be caused by reduced rainfall.
“If the AMOC collapsed, we would expect to see much more dramatic change than is currently expected due to climate change,” said Dr Paul Ritchie, of the University of Exeter.
“Such a collapse would reverse the effects of warming in Britain, creating an average temperature drop of 3.4°C and leading to a substantial reduction in rainfall (−123mm during the growing season). These changes, especially the drying, could make most land unsuitable for arable farming.”
The study conducted by researchers at the University of Exeter, following a recent paper by Professor Tim Lenton, Director of the Global Systems Institute at the University of Exeter, examines a ‘fast and early’ collapse of the AMOC. This collapse is considered ‘low probability’ at this time, despite this the AMOC has weakened by 15% over the last 50 years.
Lenton said that the worst-case scenarios must be considered when calculating risks. He commented: “Any risk assessment needs to get a handle on the large impacts if such a tipping point is reached, even if it is a low-probability event” he said.
“The point of this detailed study was to discover how stark the impacts of AMOC collapse could be.” The new study reinforces the message that “we would be wise to act now to minimise the risk of passing climate tipping points” said Lenton.
“With the land area suitable for arable farming expected to drop from 32% to 7% under AMOC collapse, we could see a major reduction in the value of agricultural output,” said Professor Ian Bateman, of Exeter’s Land, Environment, Economics and Policy Institute.