资源环境科技发展态势分析平台

By Ibrahim Sawal

Hans Neleman/Getty Images

Greenhouse gas emissions from global food production will be enough to push Earth beyond an internationally agreed goal of limiting global warming to 1.5°C, even if we halted all other emissions.

“If we don’t change what we do with food, we would miss the 1.5°C target within 30 to 45 years,” says Michael Clark at the University of Oxford. “Assuming all other emissions sources are magically reduced.”

Clark and his colleagues used data on food consumption, production and population growth to predict how emissions might change over the coming decades. They found that if we do nothing to reform global food production, the sector will contribute the equivalent of 1300 gigatonnes of carbon dioxide. That is enough on its own to miss the goal, set by the Paris climate agreement, of limiting global warming this century to 1.5°C above pre-industrial levels.

The team also found that introducing various green strategies such as increasing crop yields, consuming a healthier diet and reducing food waste would give humanity a 67 per cent chance of meeting the 1.5°C goal. “The most effective one seems to be transitioning to a plant-based diet,” says Clark.

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That scenario assumes that non-food emissions immediately reach net zero – meaning any remaining sources of carbon are offset to zero – in 2020, which is extremely unrealistic. However, if non-food emissions gradually reach net zero by 2050, reaching the Paris target is still possible if all of the green food production strategies are in place.

We should have already taken action on food, says Clark. “The longer we wait, the harder and bigger the changes need to be to meet the targets,” he says. “We need to actually back our words with actions and policies rather than just talking about things.”

He acknowledges that it will be hard to implement the strategies, but says both individuals and policymakers can do their part. “What are we willing to give up and what are we willing to lose, if we actually care about these targets?” he says.

Journal reference: Science, DOI: 10.1126/science.aba7357

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