PARIS • The effects of climate change on food production could cause 500,000 extra deaths by 2050 compared to a world without global warming, according to a study released yesterday.
If greenhouse gas emissions continue at current rates, this would cut projected increases in food availability by about a third before mid-century, the study found.
As of last year, some 800 million people in the world were undernourished, meaning they could not meet daily minimum dietary energy requirements, the United Nations' Food and Agriculture Organisation said. With the global population set to increase from seven to nine billion by 2050, food production will have to expand even more rapidly if all the world's people are to have enough to eat.
But global warming - on track to boost temperatures by 3 deg C by 2100, compared to pre-industrial era levels - is threatening to make that difficult or impossible, experts warn.
"Climate change effects are expected to reduce the quantity of food harvested, which could lead to higher food prices and reduced consumption," according to the study, published in medical journal The Lancet.
Even these grim projections may be overly optimistic, it warns, because they only count calories and fail to anticipate a likely worsening in the balance of future diets.
"Our results show that even modest reductions in the availability of food could lead to changes in the energy content and composition of diets," said Dr Marco Springmann, a researcher at the Oxford Martin Programme on the Future of Food at the University of Oxford, and leader of the study.
He said the proportion of fruits and vegetables in diets, for example, will almost certainly decline in a climate-change-addled world.
Low- and middle-income countries will probably be hit the hardest, with almost three-quarters of all climate-related deaths expected to occur in China and India.
Even if countries succeed in holding the rise in global temperature to 2 deg C, there would still be an additional 150,000 climate-related deaths due to changes in diet and calorie intake.
"Climate change is likely to have a substantial negative impact on future mortality, even under optimistic scenarios," Dr Springmann said.
The study used agricultural economic models coupled with different projections for greenhouse gas emissions and development forecasts to evaluate the impact on global food production, trade and consumption in 2050.