Energy, environmental cost of food determined by race
In the US, average white diets require the most inputs to produce. Jeff Glorfeld reports.
The eating habits of white Americans cause more damage to the environment than do those of African Americans or people of Latin American origin or descent, because they favour foods that require more water and release more greenhouse gases through their production, according to research by scientists from the University of Illinois at Chicago, and Chicago State University, both in the US.
Their report, published in the Journal of Industrial Ecology, focuses on strategies for adapting to climate change by understanding how food consumption affects the environment.
Apples, potatoes, beef and milk are among the most environmentally intense foods, write the researchers, led by the University of Illinois’ Joe Bozeman.
Estimates of the impact of these foods were obtained from various databases and previous research. Foods considered environmentally intense include those that require more water, land and energy to grow, and produce more greenhouse gases than other foods.
The researchers note that “climate change is anticipated to increase the frequency of extreme weather events that threaten sustainable economic development and the resiliency of ecosystem services”.
Bozeman and colleagues say the food system “is particularly vulnerable because of shifting weather patterns”.
They cite a 2015 report led by German researcher Isabelle Weindl, published in the journal Environmental Research Letters, which models climate change projections for the year 2050.
The results suggested that “overall crop yields will decrease in most of the US but particularly in the midwest region. North American livestock production is also expected to be negatively impacted considering maize, a primary feed crop, is projected to have declining yields due to reduced precipitation.”
For the new paper, researchers examined what different demographic populations eat, how much greenhouse gases those foods are responsible for, and how much land and water they require.
“The food pipeline – which includes its production, distribution and waste – contributes significantly to climate change through the production of greenhouse gases and requires significant amounts of water and land, which also has environmental effects,” says Bozeman.
“If we are to draft policies related to food, they can't be one-size-fits-all policies because different populations have different eating patterns, which have their own unique impacts on the environment.”
Bozeman and colleagues analysed data from the US Environmental Protection Agency's What We Eat in America – Food Commodity Intake Database, which provides per capita food and water consumption estimates for more than 500 types of food, such as apples, poultry and bread; and from the National Health and Nutrition Examination Survey, which provides estimates of individual dietary intake.
The researchers found that white people produce an average of 680 kilograms of carbon dioxide each year that can be directly linked to what they eat and drink, while people of Latin American origin or descent produce 640 kilograms and blacks 600 kilograms.
“While the difference may not be enormous, these numbers are per individual, and when you add up all those individuals, it's very clear that whites are responsible for the majority of greenhouse gases emitted as a result of their food choices,” Bozeman says.
They also found that the food habits of white people require about 7% more water, at 328,000 litres per year, than Latin Americans, whose food habits require 307,000 litres.
Meanwhile, African American eating habits require about 12% more land than other populations, which Bozeman says is driven in part by their higher consumption of chicken and apples, which are high land-use food items.
“Whites tend to drink more water and milk,” he explains. “Milk itself requires a lot of water to produce when you consider livestock cultivation, so that is part of what we think is pushing their water impacts higher.”
The report says the US food system is resource intensive, accounting for about 50% of land, 80% of fresh water, and 17% of fossil energy use. Transportation output from crop and animal farming increases greenhouse gas emissions by 33% annually.
Policies that attempt to reduce resource dependence or greenhouse gases need to also take into account individual nutrients, Bozeman says.
“If you are going to draft policies that may reduce the amount of land-intensive oranges, we need to think about other less resource-intensive sources of vitamin C,” he says.
“It gets more complex as you look closely at the food pipeline and how different populations engage with it, but we are now starting to get a better understanding on these complex dynamics in such a way that we can begin to rationally take steps to improve environmental quality.”