According to the Intergovernmental Panel on Climate Change (IPCC, 2007), the over-all impact of climate change on agriculture includes an increase of the average temperature, a change in the amount of rainfall and patterns, a rise of atmospheric concentrations of CO2, a change in frequency and severity of heat waves, drought, floods and hurricanes, and the emergence of new pests and diseases.

J. Challinor, University of Leeds, UK, and colleagues looked at data on farming, regulatory policy, markets, and technologies for maize in Africa. Average, best and worst case scenarios for current crop breeding systems showed that crop duration will become significantly shorter. This happens as early as 2018 in some locations and by 2031 for the majority of maize-growing regions in Africa. To mitigate these effects, within ten years new and improved crop varieties that are better suited to new climatic conditions between now and 2050 are urgently needed to keep crop yields constant.

The study was done for maize in Africa, but according to the researchers the underlying processes affect crops across the tropics.

• Current warming will reduce yields unless maize breeding and seed systems adapt immediately,
  A. J. Challinor, A.-K. Koehler, J. Ramirez-Villegas, S. Whitfield, B. Das,
  Nature Climate Change 2016.
  DOI: 10.1038/nclimate3061