Emily Cassidy, an Institute on the Environment graduate research assistant, discussed the impact of global diet preferences on agricultural productivity and greenhouse gas emissions in last week's Frontiers in the Environment presentation, "Redefining Agricultural Productivity: From Stuff Produced to People Fed."
"Talking about my research with other people can be awkward at times because food is a very personal thing," Cassidy said. "The choices that we make about what to eat are very much a cultural thing. It has a lot to do with our background, our traditions. So my job as a scientist is not to prescribe different diets, but to describe the impact of different diet preferences. When we make certain decisions, what impact are those decisions having on the global environment?"
Through her research, Cassidy found that just 59 percent of calories produced on croplands actually become food for people. The rest is lost in the transition from animal feed to meat and dairy products, as well as biofuel. This is problematic, particularly as more people enter the middle class globally.
"Currently we live in a world in which a lot of people are getting richer, and as incomes increase, people generally shift their diets from one that contains a lot of starches and grains and vegetables to one that contains more animal products," she said.
But making environmentally conscious dietary choices doesn't have to mean giving up your favorite foods, according to Cassidy.
"When I talk about my research with my family they think that I'm talking about just eradicating all animal products from your life," Cassidy said, "and while reducing animal products will reduce your impact on the environment, I'm not prescribing different diet preferences. You have to make decisions about what you want to eat based on your own values, of course. But we can make small changes - almost unnoticeable changes - in our diets that can significantly reduce our environmental impact."
Cassidy discussed her work with a health insurance company encouraging healthier eating by subsidizing healthier food choices at supermarkets in South Africa. While the incentive didn't change dietary choices dramatically, there was a noticeable reduction in pork, beef and dairy intake and an increase in fruit and vegetable consumption. The subsequent greenhouse gas emissions reductions were equivalent to approximately 1 percent of the nation's total emissions - a finding that makes Cassidy optimistic.
"Even though I found a very small change in the diet for this last study, it was very small but it had a reduction in greenhouse gas emissions that was significant, and that's by not even trying," she said. "That's by reducing healthcare costs, making people healthier and you get to reduce greenhouse gas emissions, too. So I think there is a lot of opportunity for us to try to curb emissions from agriculture by making different choices."
Watch Cassidy's full presentation online.
John Sisser is a communications assistant with the Institute on the Environment.