Nine in 10 people could live in countries with falling food production from farms and fisheries by the end of the century, if climate change continues unchecked.
Most efforts to study the impact of global warming look at either agriculture or seafood in isolation. Lauric Thiault at the PSL Research University in Paris and his colleagues have now examined the two simultaneously using state-of-the-art climate and crop models.
Using today’s national population trends as a guide to the possible global distribution of people in 2100, the researchers found that, in the worst-case climate scenario, about 90 per cent of the global population will live in a country where both sectors have falling food productivity by 2100. Less than 3 per cent of people will live in places where both are rising.
“Productivity losses are very likely going to be inevitable in some places. But climate mitigation has a big impact on how big those losses are going to be,” says Thiault.
Room to adapt
Agriculture will see a 25 per cent reduction in productivity under the worst-case climate scenario. If we do more to reduce greenhouse gas emissions, the decline in productivity could be as little as 5 per cent. For fisheries, the difference is a fall of 60 per cent versus one of 10 per cent. Likewise, less warming means more room to adapt: in scenarios with lower emissions, farmers in India could switch to more heat-tolerant crops such as cassava, for instance.
Poorer countries in the tropics that have the least capacity to adapt are expected to be the worst hit, but richer countries won’t escape, as food trade will be disrupted, says Thiault.
John Porter at the University of Copenhagen in Denmark says the study wrongly equates food production with food security. The last big assessment by the UN’s climate science panel says that many more socioeconomic factors play a role in whether people can get enough food and nutrition. Thiault argues productivity is still an important component of food security.