Climate change alters the global diversity of food crops

Climate change has already impacted the productivity of important food crops. The projected increasing temperatures and changing precipitation patterns affect the climatic suitability of food production areas. Changes in climatic suitability require adaptive actions on farms and will likely alter the potential volume and diversity of food crop production globally.

Existing research has mostly analysed the impacts of climate change on the four staple crops: wheat, rice, maize, and soybean. However, other food crops contribute more than 50% to the global calorie and protein supply and therefore constitute a crucial element of food security. Moreover, these crops might succeed in more diverse climate conditions than the staple crops. If climate change narrows the production potential of the staple food crops, other food crops could become even more important for global food security in the future. Therefore, to comprehensively understand the implications of climate change on food crop production, there is need for analysis on a diverse set of food crops.

In this study, we delineate suitable climate conditions for 27 major food crops using historical climatic data and examine the effect of future changes in climate suitability on food crop production volume and diversity. We define the crop-specific suitable climate conditions utilizing the Safe Climatic Space concept, based on global gridded datasets on biotemperature, precipitation, and aridity in 1970–2000 as well as crop production in 2010. Then, using future climate parameter data, we project changes in global climate suitability for the 27 food crops. The analyses cover five global warming scenarios from +1.5 °C to +5 °C.

The preliminary results indicate that the global food crop production potential on the current croplands will decrease for most crops in all five global warming scenarios. Furthermore, the potential diversity of food crops will decrease significantly at low latitudes but increase in other areas. In all five scenarios, areas near the equator will become unsuitable for most studied crops. On the other hand, on the current extent of cropland, the potential production area of especially oil crops and starchy roots will expand in the northern hemisphere.

For many crops, there is distinct difference in the magnitude of lost production and diversity potential between global warming of +2 °C and +3 °C, highlighting that it is important to restrict global warming at the very maximum to +2 °C. The results of this study could provide insights for agricultural adaptation to climate change by illustrating opportunities for geographically shifting or expanding production in regions where climate suitability is projected to change. Further, the results could identify potential substitute crops for regions where climate conditions might become unsuitable for the currently cultivated food crops.