The world's top 10 crops  barley, cassava, maize, oil palm, rapeseed, rice, sorghum, soybean, sugarcane and wheat  supply a combined 83 percent of all calories produced on cropland. Yields have long been projected to decrease in future climate conditions. Now, new research shows climate change has already affected production of these key energy sources  and some regions and countries are faring far worse than others.

Published in PLOS ONE, the University of Minnesota-led study, conducted with researchers from the University of Oxford and the University of Copenhagen, used weather and reported crop data to evaluate the potential impact of observed climate change. The researchers found that:

• observed climate change causes a significant yield variation in the world's top 10 crops, ranging from a decrease of 13.4 percent for oil palm to an increase of 3.5 percent for soybean, and resulting in an average reduction of approximately one percent (-3.5 X 10e13 kcal/year) of consumable food calories from these top 10 crops;
• impacts of climate change on global food production are mostly negative in Europe, Southern Africa, and Australia, generally positive in Latin America, and mixed in Asia and Northern and Central America;
• half of all food-insecure countries are experiencing decreases in crop production  and so are some affluent industrialized countries in Western Europe;
• contrastingly, recent climate change has increased the yields of certain crops in some areas of the upper Midwest United States.

These findings indicate which geographical areas and crops are most at risk, making them relevant to those working to achieve the U.N. Sustainable Development Goals of ending hunger and limiting the effects of climate change. Insights like these lead to new questions and crucial next steps.

This is a very complex system, so a careful statistical and data science modeling component is crucial to understand the dependencies and cascading effects of small or large changes.