Environ. Res. Lett. 9, 074003 (2014)

The greatest climate change impacts on agriculture are not expected until towards the end of the twenty-first century. However, the greatest growth in food demand is expected in the next 20 years. This demand growth creates a potential pinch point in which relatively small-magnitude climate change impacts could pose significant challenges for food security.

David Lobell from Stanford University and Claudia Tebaldi from the National Center for Atmospheric Research, US, estimate global wheat and maize yields over this critical period. They find that climate change increases the chance of climate trends causing a 10% yield loss over a 20-year period from less than a 1 in 200 chance — under internal climate variability alone — to a 1 in 10 chance for maize and 1 in 20 chance for wheat. The probability of climatic conditions that halve yield trends over a 10-year period also greatly increased, with a roughly 1 in 4 chance for maize and 1 in 6 chance for wheat. Such impacts, while still relatively unlikely, may warrant further consideration in risk planning.