Study: The risk of simultaneous crop failures worldwide is vastly underestimated Berlusconi’s will: These people get his billions in assets

It only takes two extreme weather events in two major grain regions to make wheat scarce worldwide. Scientists have therefore investigated what crop losses were associated with such events in the past and how climate change now makes such situations more likely.

The group led by Kai Kornhuber of Columbia University in New York City has published their results in the journal Nature Communications. Her conclusion: “The research shows that these kinds of simultaneous events are largely underestimated.” This consequence of climate change is therefore likely to be much more common than previously assumed: “We need to prepare for this kind of complex climate risk in the future, because the models currently do not seem to capture this risk well.”

Crop failures are likely to increase

But back to this study: “Concurrent crop failures in key growing regions pose a systemic risk, as associated rising food prices can lead to conflict and malnutrition in import-dependent countries,” the study authors write. They focused on wheat and corn. About two-thirds of the world’s production comes from the regions of North America, Western Europe, Eastern Europe, India and East Asia.

High and low pressure areas, which sometimes barely move for weeks and therefore cause drought or extreme precipitation, are usually caused in the northern hemisphere by certain constellations in the jet stream. This can create large waves, the so-called Rossby waves. If these do not move but remain stationary, high and low pressure areas can remain above an area for a long time.

We have to take that into account

The team searched historical data (1960 to 2014) for events where more than one granary had low yields associated with Rossby waves. Using multiple models, it determined that during seven-peaked Rossby waves, wheat and corn yields were up to 7 percent lower in East Asia, 6 percent lower in North America and 3 percent lower in Eastern Europe.

In the model simulations of the future development (2045 to 2099, with a very strong increase in carbon dioxide emissions), the risk of high crop losses increases, especially when North America and East Asia are affected by the Seven Mountains Rossby waves . In the case of five-mountain Rossby waves, the likelihood of high crop losses increases if North America and Eastern Europe on the one hand and India and Western Europe on the other are affected. (leo/sda/dpa)