Placing a tax on food products such as meat and dairy could cut greenhouse gas emissions by up to 1 billion metric tonnes (1.1 billion US tons) and save half a million lives a year, according to a new study by Oxford Universty.

The study, a collaboration between the Oxford Martin Program on Future of Food in the UK and the International Food Policy Research Institute in Washington DC, is the first global analysis to estimate the impact placing an emissions levy on food products could have on both global emissions and human health.

Their findings, published in the journal Nature Climate Change, suggest that placing the tax on the foods with the highest carbon footprints, such as beef and milk, would lead to lower consumption, and up to 1 billion tonnes of carbon emissions could be avoided in the year 2020.  

“Emissions pricing of foods would generate a much-needed contribution of the food system to reducing the impacts of global climate change,” said lead author Dr Marco Springmann of Oxford, in a statement. “We hope that’s something policymakers gathering this week at the Marrakech climate conference will take note of.”

The study also suggests the tax could save half a million lives a year due to healthier diets too. “If you’d have to pay 40 percent more for your steak, you might choose to have it once a week instead of twice,” added Dr Springmann.

To reach the optimal amounts for the suggested taxes in terms of both emissions and health the researchers modeled various scenarios based on the emissions generated by different food types, the damages to climate those emissions are expected to cause, and the possible changes to the likelihood of dying from diet-related diseases like type 2 diabetes, heart disease, strokes, and cancer.

They then worked out how much less each of the food products would be consumed as a result of the taxes.

They concluded that if beef, which has one of the highest carbon footprints due to methane emissions and deforestation for farming, had a 40 percent tax imposed on it, it could lead to a 13 percent drop in global consumption. Similarly, a 20 percent tax on milk could lead to an 8 percent drop in consumption.  

The researchers also took into consideration that low-income parts of the world may seriously suffer if the price of food went up, so they suggest combining the taxes with subsidies on fruit and vegetable as well as income compensation to ensure the diets of poorer nations are not negatively affected.

The study concluded that, if done properly, an emissions tax on food could be a viable “health-promoting climate-change mitigation policy” that could work globally regardless of the differences in the wealth of countries.

Food production causes a quarter of global greenhouse gas emissions. These emissions are steadily increasing as the world gets richer, and the consumption of meat particularly goes up. The authors warn we ignore this at our own peril.

“So far, food production and consumption have been excluded from climate policies, in part due to concerns about the potential impact on food security,” said Dr Springmann. “Here we show that pricing foods according to their climate impacts could not only lead to lower emissions, but also to healthier diets in almost all countries around the world.”