Crop production in Britain will decrease dramatically if climate change causes the collapse of a vital pattern of ocean currents, new research by the University of Exeter suggests.
The paper, published in the Nature Food journal, looks at what would happen if the Atlantic Overturning Circulation (AMOC), which transports heat from the tropics to the UK, collapses because of climate change.
Dr Paul Ritchie of the University of Exeter warned AMOC collapse would leave Britain cooler, drier and unsuitable for many crops, causing the ‘widespread cessation of arable farming’ across the UK.
“Such a collapse would reverse the effects of warming in Britain, creating an average temperature drop of 3.4degC 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,” he said.
The study examines a ‘fast and early’ collapse of the AMOC, which is considered ‘low probability’ and ‘rare’ at present, though the AMOC has weakened by an estimated 15 per cent over the last 50 years.
However, Professor Tim Lenton, director of the Global Systems Institute at the University of Exeter, said worst-case scenarios must be considered when calculating risks.
He said: “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.
“The point of this detailed study was to discover how stark the impacts of AMOC collapse could be.”
The study follows a recent paper by Prof Lenton and colleagues, which warned that economic assessments detailing the potential future risks of climate change, had ‘grossly underestimated’ many of the ‘most serious consequences for lives and livelihoods’.
The new study therefore reinforces the message that ‘we should be wise to act now to minimise the risk of passing climate tipping points,’ Mr Lenton said.