Researchers have taken another stab at an answer to the question that many food experts have been asking: Does climate change affect world food production? And what are the answers?
After studying 15 years of data, the researchers reached the conclusion that increasing temperatures in Madagascar — an island nation with a top temperature of 79 degrees Fahrenheit — affects food production in ways similar to changes that occur in North America and other temperate regions.
But they also found that the island’s wind storms and cyclones — often involved in deadly storms that plunge villagers into the ocean, killing thousands — actually have an impact on food production even when temperatures are rising.
Climate change often is described as a canary in the coal mine when it comes to warnings about food production and other crucial environmental issues. But the link between temperature and food production has been hotly debated. And after the first round of research to determine whether the link was negative or positive came out negative, experts and governments re-evaluated their analysis.
Dr. Steven Cochrane, an economist who has studied food and climate change, said the new analysis comes at the right time. Other researchers’ negative findings were drawn from historical data, which looked back at the exact time when global warming occurred and under various conditions. His new work looks at data from 2005 to 2012 and so analyses when the world was in a distinct state of over-consumption.
“I think this is a very important paper because the present data is solid and provides a consistent structure for evaluating the issue,” he said.
Cochrane, who is a senior fellow at the E3G think tank, was not involved in the research. But one of the researchers behind the new analysis, Dr. Elisa Maestros, is the manager of a hub of more than 40 scientists from 13 countries who are investigating different aspects of climate change in Madagascar.
The conclusion: “Higher heat stress from climate change poses challenges for agriculture in Madagascar and elsewhere,” she wrote in the paper, which was published in Geophysical Research Letters, a journal of the American Geophysical Union. “In addition, these findings suggest that excessive heat stress in Madagascar can exacerbate severe seasonal effects on agriculture and economic activity, and may also directly harm the ecological systems that support biodiversity.”
The researchers compared the amount of rainfall with the amount of heat stressed by heat waves. Those extremes can cause flooding, rainfall or wildfires in agricultural regions. They found that Madagascar’s cyclones increase as temperature rises and increase the amount of heat stressed by storms. When there are cyclones, they increase during a time of increased crop plantings.
Food production depends on microorganisms that coexist with plants, Maestros wrote. Plants don’t survive climate change, as they do in more temperate regions.
This shift, she wrote, can be seen in a longer-term record that looks back at weather patterns beginning in 1900.
“In Madagascar, the poorest communities, who live and labor in the degraded soils and mud flats of hot and dry southwestern Madagascar, are coping with extreme climate fluctuations that the existing evidence and climate simulations suggest will intensify,” she wrote.
Few details about climate change’s effects on agriculture are clear. None of the regions included in the new study is likely to be weathering the climate change seen in other parts of the world. All are susceptible to cyclones, which can sweep villages into the ocean for days.
And although Hurricane Barbara’s damage was devastating to the region, experts could not point to climate change as a major cause.
That’s not to say that food shortages and poverty aren’t the result of climate change in Madagascar. The island nation is in the midst of a food crisis, with food prices skyrocketing this year. That’s due in part to rain shortages in one of the country’s main crops, bananas.
As agriculture flourishes with higher temperatures in the dry portion of the country — Malagasy soil is dry, making it less hospitable to fruit trees — farmers are forced to buy additional food to keep their harvests in balance. A rise in temperatures also can make crops grow sooner than they normally would — creating a fire hazard and worsening the future demand for water.
But Maestros warned that individual farmers and fishers do not view climate change as a significant factor in their current diets and expenses.
“These findings, to our knowledge, demonstrate that increase in temperature does not create sufficient incentives for low-income Malagasy to adapt their food preparation to climate change, as climate change has affected food security and hunger in these areas only indirectly,” she wrote.