Food-growing areas will see drastic changes to rainfall and temperatures if global heating continues at current rate
A third of global food production will be at risk by the end of the century if greenhouse gas emissions continue to rise at their current rate, new research suggests.
Many of the world’s most important food-growing areas will see temperatures increase and rainfall patterns alter drastically if temperatures rise by about 3.7C, the forecast increase if emissions stay high.
Researchers at Aalto University in Finland have calculated that about 95% of current crop production takes place in areas they define as “safe climatic space”, or conditions where temperature, rainfall and aridity fall within certain bounds.
If temperatures were to rise by 3.7C or thereabouts by the century’s end, that safe area would shrink drastically, mostly affecting south and south-eastern Asia and Africa’s Sudano-Sahelian zone, according to a paper published in the journal One Earth on Friday.
However, if greenhouse gases are reduced and the world meets the goals of the Paris agreement, in limiting temperature rises to 1.5C or 2C above pre-industrial levels, then only about 5%–8% of global food production would be at risk.
Matti Kummu, an associate professor of global food and water at Aalto University and lead author of the paper, said: “A third of global food production will be at risk. We should be worried, as the climate safe space is quite narrow. But there are measures we can take in reducing greenhouse gas emissions. And we should empower people and societies in the danger zones, to reduce the impact and increase their resilience and adaptive capacity.”
Although rising temperatures could increase food production in some areas that are currently less productive, such as the Nordic regions, that would not be anywhere near enough to offset the loss of important food producing regions in the south, said Kummu.
“There will be winners as well as losers, but the wins will be outweighed by the losses, and there is just not enough space for food production to move – we are already at the limits,” he said.
Livestock farming would be affected, as well as the risks to crop production, he said, and many areas were likely to suffer large increases in water scarcity. The researchers examined the impacts of climatic changes on 27 of the most important food crops and seven types of livestock.
By the end of this century, in a high-emissions scenario, there could be as much as 1.5m sq miles (4m sq km) of new desert around the world, the research found.
Under 1.5C to 2C of warming, the boreal forests of northern America, Russia and Europe would shrink from their current 7m sq miles to about 6m sq miles by 2100. In a high emissions scenario, only 3m sq miles would remain, the researchers forecast.
The paper adds to previous research that has found that global heating is already having an impact on agricultural productivity.
Source: Fiona Harvey, www.theguardian.com