BBC News: 21st Century US 'dustbowl' risk assessed

The 1930s witnessed a deep drought in the US that resulted in huge agricultural losses. via Getty Images

The 1930s witnessed a deep drought in the US that resulted in huge agricultural losses.
via Getty Images

US scientists have modeled how a 1930s-like "dustbowl" drought might impact American agriculture today, and found it to be just as damaging.

But the research shows the effects to be very sensitive to temperature, meaning the potential losses would be far worse later this century if Earth's climate heats up as expected.

A repeat of 1930s weather today would lead to a 40% loss in maize production.

In a 2-degree warmer world, it becomes a 65% reduction, the team projects.

"The 1930s were really extreme and, yes, the chances of the same precipitation distribution happening again are small," explained Joshua Elliott, from the University of Chicago's Computation Institute.

"But the temperature distribution wasn't any more extreme than we've seen in 2012 or 1988, for example.

"And what we see at higher temperatures is that these crops - maize and also soy - are so sensitive that an average year come mid-century could be as bad as 1936, even with normal precipitation," he told BBC News.

Click here to listen to Joshua Elliott speak at the AAAS: "Iowa could one day become the cotton state"

Dr Elliott was speaking here at the annual meeting of the American Association for the Advancement of Science.

He has been taking part in a discussion session on so-called "food shocks", where the failure of key crops can lead to rapid global price hikes.

Dr Elliott is a member of a joint US-UK task-force that last year assessed the resilience of the world's food system. The fall-out from extreme weather was deemed to be a major concern, especially if future climate change is not moderated by a reduction in the emission of heat-trapping gases from the burning of fossil fuels.

Looking at the production of the major grains - rice, wheat, maize and soybeans - the taskforce's scientists found that the chances of a one-in-100-year production disruption was likely to increase to a one-in-30-year event by 2040.

Implementing reforms that would enable the system to cope better in the future was seen as a priority.

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Originally published by Jonathan Amos | BBC Science Correspondent, Washington DC