In the late summer of 2016, wheat growers in France realized something was wrong. Their harvest was smaller than usual - much smaller. The farmers were used to their yields being very consistent. Wheat yields usually changed by no more than five percent from one year to the next. But this year was different.
Although, it wasn't obvious right away exactly what the problem was. There had been an unusually warm spell that winter. Later in the year, some intense rains had fallen. These events led to unexpected issues. The heavy rains, for instance, leached nutrients out of the soil. The heat and damp increased the spread of diseases. None of these issues seemed too bad as they were happening. But when it came time to harvest the wheat, yields across France were one-quarter lower than normal. In some regions, they were just half of what they had been.
"That was amazing to me," says Senthold Asseng, who works at the University of Florida in Gainesville, where he uses computers to analyze data and predict crop harvests. "It was a real warning that you don't need to wait for a big shock like a heat wave or a drought. A shock to production could also come about by having three or four smaller changes that all come together in one season."
France is a wealthy country. So it had other sources of grain and food. Other than the wheat farmers, few French people were affected. But in a poor country, such a huge drop in crop yields could worsen poverty, or even bring on starvation.
When people think about how their lives will be affected by climate change, they might imagine living in a world with shorter winters and longer summers. They might envision coastal cities losing ground to sea level rise. They might even expect more extreme weather, such as hurricanes or wildfires.
All of those effects have struck various parts of the world. But climate change is also affecting what we eat. With warmer temperatures and more pests, farms will produce less food. And farmers will have to work harder to grow what food they do bring to harvest. Some crops might even be less nutritious. We may eat less of foods that are vulnerable to climate change - such as wheat and corn - and more of those crops that can better tolerate drought.
Scientists are studying these issues and learning more about how climate change will affect food supplies. They're also developing new crops and new growing techniques to help farmers adapt to the coming changes.
