The world’s land and water resources are being exploited at “unprecedented rates,” a new United Nations report warns, which, combined with climate change, is putting dire pressure on the ability of humanity to feed itself.
The report, prepared by more than 100 experts from 52 countries and released in summary form in Geneva on Thursday, found that the window to address the threat is closing rapidly. A half-billion people already live in places turning into desert, and soil is being lost between 10 and 100 times faster than it is forming, according to the report.
Climate change will make those threats even worse, as floods, drought, storms and other types of extreme weather threaten to disrupt, and over time shrink, the global food supply. Already, more than 10% of the world’s population remains undernourished, and some authors of the report warned in interviews that food shortages could lead to an increase in cross-border migration.
A particular danger is that food crises could develop on several continents at once, said Cynthia Rosenzweig, a senior research scientist at the NASA Goddard Institute for Space Studies and one of the lead authors of the report.
The report offered a measure of hope, laying out pathways to addressing the looming food crisis, although they would require a major reevaluation of land use and agriculture worldwide as well as consumer behavior. Proposals include increasing the productivity of land, wasting less food and persuading more people to shift their diets away from cattle and other types of meat.
The summary was released Thursday by the Intergovernmental Panel on Climate Change, an international group of scientists convened by the United Nations that pulls together a wide range of existing research to help governments understand climate change and make policy decisions. The IPCC has been writing a series of reports, including one last year on the disastrous consequences if the planet’s temperature rises just 1.5 degrees Celsius above its preindustrial levels, as well as an upcoming report on the state of the world’s oceans.
Barring action on a sweeping scale, the report said, climate change will accelerate the danger of severe food shortages. As a warming atmosphere intensifies the world’s droughts, flooding, heat waves, wildfires and other weather patterns, it is speeding up the rate of soil loss and land degradation, the report concludes.
Higher concentrations of carbon dioxide in the atmosphere — a greenhouse gas put there mainly by the burning of fossil fuels — will also reduce food’s nutritional quality, even as rising temperatures cut crop yields and harm livestock.
In some cases, the report says, a changing climate is boosting food production because, for example, higher temperatures will mean greater yields of some crops at higher latitudes. But on the whole, the report finds that climate change is already hurting the availability of food because of decreased yields and lost land from erosion, desertification and rising seas, among other things.