Attempts to measure the impacts of climate change on agriculture must invariably rely on models that translate changes in climate to changes in agricultural outcomes. This need for models exists even when assessing the impacts of climate trends that have already occurred, since simultaneous changes in other factors that affect agriculture, such as technologies and government policies, preclude direct observations of impacts. Over several decades, many approaches to developing these models have evolved, with most falling into one of two camps.

In adapting US agriculture to the climate of the 21st century, a key unknown is whether cropping frequency may increase, helping to offset projected negative yield impacts in major production regions. Combining daily weather data and crop phenology models, we find that cultivated area in the US suited to dryland winter wheat–soybeans, the most common double crop (DC) system, increased by up to 28% from 1988 to 2012.

The world faces a small but substantially increased risk over the next two decades of a major slowdown in the growth of global crop yields because of climate change, finds this new research by Stanford professor David Lobell and Claudia Tebaldi from the National Center for Atmospheric Research