A tax on carbon-intensive ground beef could make you think twice about eating a burger for dinner. But is it enough to make you eat a salad instead?

Even economists and public health co-authors of a new economic modeling study disagree on the answer.

In a new analysis, researchers from the University of Oxford and the University of Reading collaborated to see how implementing a tax on foods like red meat that produce more greenhouse gases could help the environment and improve people’s health. They found that adding a tax could change consumer behavior, but the authors disagree about what the research actually means in the real world.

For Adam Briggs, a public health researcher at the University of Oxford and lead author of the study, the findings suggest that putting a carbon tax on high emissions foods could be a positive for both the planet and the health of U.K. consumers. He conceded that the tax is unlikely to be popular in practice.

“The appetite for increased taxes in the U.K. is pretty low at the moment,” Briggs said. “We see this more as a stimulus for conversation.”

While Britons would see their weekly shopping bills go up by about the price of a latte, the tax revenue for the British government could reach as high as £3.6 billion ($5.26 billion), and could cut greenhouse gas emissions by between 16.5 million and 18.9 million metric tons of carbon dioxide equivalent, Briggs said.

The modeled scenarios also predicted that consumers would delay or avert death from heart disease and cancer, an effect the researchers say could result from added fiber intake and changing fat consumption.

Beef and lamb were among the most highly priced food items under their modeled tax system, with price increases ranging from 5 to 45 percent. For consumers, that would translate to about £1.70 to £1.80 per kilogram, said Briggs.

Those higher red meat prices meant consumers were more likely to buy more environmentally friendly poultry and pork, which only saw a price increase of between 5 to 10 pence per kilogram.

Altogether, Briggs estimated the total impact of the the tax on weekly shopping would be an increase of £2.50 per week, which he said would be enough to change consumer shopping patterns.

‘This is a bad idea’

Richard Tiffin, a professor of applied economics at the University of Reading and a co-author of the study, was less convinced. He questioned whether the potential benefits to the environment from a tax would outweigh the financial burden it could impose on low-income consumers and potential harm to British farmers.

The positive impact of people who did change their diets based on the price change also might not be enough to counterbalance those with the worst diets for the environment.

“I’m not fond of taxing in this way at all. We take the results to illustrate why this is a bad idea,” he said. “No one disputes the facts. It’s more, do we think the impacts are sufficiently large?”

Tiffin described the taxation approach as a “blunt instrument” that would be less effective than a method that took a deeper look at why consumers make specific purchasing choices and that tried to develop a more targeted approach to changing dietary choices.

Both groups of researchers agree that finding some way to address emissions from food production is important. Up to 30 percent of total global greenhouse gas emissions comes from agriculture and associated land-use change combined.

“There is a potential market failure in agriculture as the true social cost of carbon (the wider costs to society of GHGEs [greenhouse gas emissions], such as their direct and indirect impacts on food production and health) is not included in the price of food and therefore is neither paid for nor is visible to the consumer,” the study’s authors wrote.

The researchers used four different scenarios to model how consumption patterns and health in the United Kingdom would change if the British government implemented a tax of £2.86 per metric ton of CO 2 equivalent (CO 2 e) per 100 grams of food. First, the researchers looked at what would happen if this tax were applied to foods that produce higher than the average amount of emissions (0.36 kg of CO 2 e). In a second scenario, they used the same tax rate but added subsidies for foods that generated less than the average greenhouse gas emissions.

They then repeated the first two scenarios but included a 20 percent tax on sugar sweetened beverages like sodas, energy drinks and fruit juices. They included the additional tax to avoid an unintended consequence of putting a price on carbon: Because sugar has a relatively small carbon footprint, consumers could be inadvertently pushed toward purchasing cheaper, less healthy foods.

Dietary choice remains a mystery

In all four scenarios, the models assume that 100 percent of the additional taxes would be passed on to consumers.

The researchers found the highest tax revenue of £3.4 billion in the scenario without subsidies for low-emissions foods, and that included the 20 percent sugar tax.

In scenarios with subsidies, consumers shifted purchases to more fruits and vegetables and ate less dairy products.

The U.K. researchers aren’t the first to suggest taxing foods with large carbon footprints. Last November, Chatham House in London released a report outlining how a tax on red meat could help reduce overall greenhouse gas emissions from agriculture. The report noted that meat consumption in industrialized countries is currently twice the amount considered healthy by experts. That excess consumption was also contributing to increases in obesity, cancer and Type 2 diabetes.

The British Parliament has also debated the merits of implementing a 20 percent tax on soft drinks, which is part of how the researchers settled on that value in their models.

“We found that a 20 percent tax had a very meaningful impact that led to much greater reduction in consumption from the baseline, but the effect on greenhouse gas emissions was fairly small,” Briggs said.

Tiffin said the co-authors’ internal debate reflected a broader dichotomy among researchers about how to change consumers’ eating patterns.

“We don’t understand why people make the dietary choices that they do,” he said.

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500