How we produce food matters as much for the climate as what we eat

A new study finds changing the food system is vital to keeping global warming below potentially dangerous levels.

Why it matters: The global food system is projected to generate nearly 1.5 trillion tons of greenhouse gas emissions over the next 80 years, which by itself is enough to ensure the Earth warms by some 2 C over pre-industrial levels. Preventing that will require changes that go beyond what food we eat to how we produce it.

By the numbers: In the study, published in the journal Science, researchers calculated the emission reductions that could be achieved through various changes to the food economy, both behavioral and technological.

• The biggest savings would come from a near-complete global switch to a plant-heavy diet, which would cut 750 billion tons of greenhouse gas emissions.
• Reducing daily consumption to the appropriate number of calories by age — around 2,100 calories for most adults — would save 450 billion tons.
• More efficient farming would cut almost 600 billion tons.
• Engineering better-yielding crops through genetics would reduce some 210 billion tons.
• Vastly reducing food waste would save almost 400 billion tons.

How it works: Going halfway on all five of these recommendations — plus cuts to fossil fuels, an even bigger source of greenhouse gas emissions — should be enough to prevent the world from warming 2 C by 2100.

• While most experts consider it extremely unrealistic to expect a global move away from meat — especially when consumption continues to increase — mixing some behavioral changes with technological reforms seems more achievable.