A study by a team of researchers in the United States has shown that making a small and simple change in dietary habit can help America achieve three-fourths of the greenhouse gas (GHG) reduction target set by the Obama administration.

The research paper, authored by Helen Harwatt, Joan Sabate, Gidon Eshel, Sam Soret and William Ripple, analyses how substituting one food for another – beans for beef – could provide a fillip to achieving the climate change target.

The researchers demonstrate that eating beans instead of beef could achieve approximately 46-74 per cent of the reduction needed to meet the 2020 GHG target for America. Beef is the highest GHG-emitting food item while beans is a low GHG-intensity food. The emissions from the former range from 9kg to 129kg CO2e/kg. Legumes, on the other hand, emit only 12kg CO2e/kg and are a high-protein food.

The substitution will thus not only help cut down on emissions; it will also improve nutrition. According to the US Department of Agriculture, beef provides 332 kilocalories (kcals) and 14.4 grams (g) protein per 100g of raw weight, whereas raw beans provide 341kcals and 21.6g protein per 100g of weight.

The paper further argues that the shift can help free up 42 per cent of the US cropland, which is roughly 1.6 times the surface area of California. “This type of land sparing is particularly relevant to climate change goals given the potential for enhancing carbon sequestration, which will likely augment GHG reductions,” the researchers reason.

This is the first study of its kind that analyses potential diet changes in the context of meeting country-wide GHG reduction targets. Though the substitution of beef does not satisfy the US GHG reduction targets completely, achieving three-fourths of it would be no mean feat.

People across the world are already warming up to the idea of changing dietary habits if it helps the environment. The paper cites a survey conducted in many countries to prove the same. According to this, 44 per cent of those surveyed were likely to reduce meat consumption, and 15 per cent had already reduced the consumption of meat. So, there is a willingness to change. Maybe a nudge from the policymakers can help accelerate this shift.

Read the full report here (PDF).