Saturday, May 15, 2021

Food Shortages and Global Warming

 The media sometimes publish scary stories by high-lighting the scientists worse case scenarios. For the average reader we often miss the many caveats that are included in research papers so one has to be wary of some reporting. 

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 researchers at Aalto University in Finland have calculated.

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. 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.

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.

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.

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 Matti Kummu, associate professor of global food and water at Aalto University and lead author.

“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.

Third of global food production at risk from climate crisis | Climate change | The Guardian

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