Crop yields seen falling without climate action – report

The planet could be struck by a wave of “unprecedented” crop failures in the next 20 years if global greenhouse gas emissions continue as usual, according to a recent report released by Chatham House that examines the compounding threats posed by climate change.

The London-based policy institute published its findings in anticipation of this year’s UN Climate Change Conference in Glasgow in November (COP26), which Chatham House researchers describe as a “critical opportunity.” If highly emitting countries fail to take dramatic climate action to reduce their emissions, they warn, many of the climatic changes they anticipate “are likely to be locked in by 2040, and become so severe they go beyond the limits of what nations can adapt to.”

The report notes that unless greenhouse gas emissions are sharply reduced, the planet has a less than 5 percent chance of capping global warming below 2 degrees Celsius, the key benchmark set in the 2015 Paris climate accord.

In the report’s section on food security, researchers detailed a litany of risks that climate change could pose to global agriculture. They project that agriculture will need to produce nearly 50 percent more food by 2050 to feed a growing population. But as global demand increases, crop yields could drop by 30 percent as farmers contend with a hotter and more volatile planet.

As the planet warms, the report says, farms will be increasingly exposed to volatile droughts and heatwaves. By 2050, an anticipated 40 percent of the planet’s cropland will be exposed to severe drought for at least three months per year, and the breadbaskets of the United States and southern Russia could be among the regions most affected. Europe, the report said, is likely to experience the largest increase in agricultural drought, “with the central estimate indicating that nearly half the cropland area will experience severe periods of drought by 2050.”

By the 2040s, the United States, China, Brazil and Argentina, which grow 87 percent of the world’s maize, could suffer a steep drop in their maize production—all at the same time. “The probability of a synchronous crop failure of this order during the decade of the 2040s is just less than 50 percent,” write Chatham House researchers.

Farmers will also have to contend with a decline in the length of crop seasons and long stretches of water scarcity. The report anticipates that East and South Asia will be particularly hard hit, with 230 million people subjected to prolonged drought by 2040. Outside of Asia, Africa will likely have the greatest number of people facing drought, exceeding 180 million by 2050. 

Many regions also will have to manage coastal and river flooding. By 2100, the report says, 75 million people in East, South, and Southeast Asia will face coastal flooding every year. “Across these three regions,” write researchers, “around 11 times more people will be impacted by coastal flooding than under a scenario in which climate change is averted.”

Chatham House’s report concluded with a bleak vision for the future of the planet, where lives are shorter, food is more scarce, and 3.9 billion people “are likely to experience major heat waves.”