How does climate change affect what we eat?

Researchers at the London School of Hygiene & Tropical Medicine are exploring the health implications of reducing greenhouse gas emissions, including the effects of climate change on global food production
Cows grazing on a hill
Western diets are a contributing factor to climate change issues
Providing food for the growing population in the face of these environmental changes will be one of the great challenges of our century.

Chikumbutso Patson Kayira, a 45-year-old Malawian farmer, is becoming increasingly nervous that climate change is going to destroy his livelihood and prevent him from providing for his family.

He relies on a steady amount of rainfall for the maize that feeds his family of five, but changes to weather patterns over recent years have halved his yield.

In past years, he has routinely harvested 2,500 kilograms of maize. Now, he is relieved if he can produce half that amount.

"In the coming years we may have a season without any rain", he says dismally.

This story from the London School of Hygiene & Tropical Medicine draws attention to the externalities caused by food production as well as broader attitudes to climate change.

Researchers at the School are currently exploring the health implications of different policies to reduce greenhouse gas emissions as well as the health effects of climate change for global food production.

What are the trade-offs between the production of the foods we want to eat and the environmental cost to the planet?

Global Diet and Climate Change

Western diets, heavy in protein and starch, are a contributing factor to climate change issues, says the School's Dr Alan Dangour, Reader in Global Health.

Rice grain crops can be equally problematic, however, omitting one fifth of the methane produced by humans.

"We need to realise that the production of food can have a major impact on the environment due to it being a major contributor to environmental stress, both through greenhouse gas emission and water use", says Dr Dangour.

It is not simply a case of forcing the world's inhabitants to become vegetarians, he says, but a shift towards fruit and vegetables would consume less water and produce fewer emissions.

Dangour’s team has calculated that if diets met the recommendations set out by the World Health Organization, greenhouse gas emissions could fall by almost 20%.

"It's the balance and the trade-offs", he says. "What are the trade-offs between the production of the foods we want to eat and the environmental cost to the planet?

"If you change the balance of animal-sourced foods and increase the amounts of fruits and vegetables in the diets, then that has clear demonstrated public health benefits."

Keeping a Lid on Climate Change

The rains that once nurtured Chikumbutso Kayira's crops now arrive for just two months of a year, the farmer estimates, as concerns turn again to broader patterns of climate change and the global consequences it will cause.

Last year in Paris, many of the world's nations committed to a series of goals to mitigate climate change – one of which was to limit the global rise in temperature to two degrees centigrade.

Kevin Anderson, Professor of Energy and Climate Change from the University of Manchester, says we have entered the realm of 'dangerous' climate change, with little chance of keeping global temperature rises below two degrees without a complete revolution in attitude.

Half the world's carbon dioxide emissions come from just 10% of the population, he says, with the actions of richer countries having a punishing effect on agricultural nations.

Sir Andy Haines, Professor of Public Health at the London School of Hygiene & Tropical Medicine, says the intention is "to stay below two degrees", but agrees that action is urgently needed.

"Measures are currently not in place to achieve this goal", he says.

"Providing food for the growing population in the face of these environmental changes will be one of the great challenges of our century."