Global agriculture could go into steep, unanticipated declines due to complications that scientists have so far inadequately considered. So say three new reports published in this week's Proceedings of the National Academy of Sciences. Predicted changes from 1- to 5-degree C temperature rises in coming decades fail to account for seasonal extremes of heat, drought or rain, multiplier effects of spreading diseases or weeds, and other ecological upsets. All are believed more likely in the future, according to The Earth Institute at Columbia University:
"Many people assume that we will never have a problem with food production on a global scale. But there is a strong potential for negative surprises," said Francesco Tubiello, a physicist and agricultural expert at the NASA/Goddard Institute of Space Studies who coauthored all three papers. Existing research estimates that developing countries may lose 334 million acres of prime farm land in the next 50 years. After mid-century, continuing temperature rises—5 degrees C or more by then—are expected to start adversely affecting northern crops as well, tipping the whole world into a danger zone.
Julia Whitty is Mother Jones' environmental correspondent. You can read from her new book, The Fragile Edge, and other writings, here.