Climate Change and U.S. Consumer Food Choices.
Nemec Boehm, Rebecca.
Background: Climate change is altering the growing conditions under which agricultural
crops are produced, putting at risk our ability to grow enough high quality food now and
for future generations. At the same time, the production, processing, transportation,
distribution, and sale of food causes greenhouse gas emissions (GHGEs) that contribute
to climate change. Consumers may be ... read moreable to alter their food choices to mitigate GHGEs
caused by the food system. However, little is known about the carbon footprint of food
choices in the U.S. or consumer interest in mitigating GHGs caused by the food system.
Therefore, the objective of this research is to determine if there are GHGE mitigation
opportunities through changes in U.S. consumer food choices and to assess consumer
responses to climate driven quality changes in foods and beverages. Methods: This
project used a variety of methods, including economic input-output life cycle
assessment, stated preference valuation, ordinary least squares linear regression,
multinomial logistic regression, and hedonic sensory evaluation using both primary and
secondary data sources. Objective 1 was to estimate the life cycle greenhouse gas
emissions (GHGEs) caused by U.S. household food expenditures using data collected from
the National Household Food Acquisition and Purchase Survey and to assess association
between GHGEs and household sociodemographics. Objective 2 used data generated in
Objective 1 to determine if lower spending on meat by U.S. households is associated with
reduced GHGEs, improved nutritional quality, greater accordance with the 2010 Dietary
Guidelines for Americans, and lower food costs. Objective 3 assessed consumer responses
to climate driven quality changes in brewed green tea and quantified consumer
willingness to pay for climate mitigation in tea production and other product attributes
such as environmental sustainability in production, nutrition, and ethical production
attributes. Results: U.S. household food expenditures accounted for 6.8% of total U.S.
GHGEs in 2013. The majority of GHGEs come from the purchase of meat and animal products
and are generated at the agricultural stage of the food supply chain. More highly
educated and white households generated more emissions from food expenditures compared
to non-white households and those with lower educational attainment. Households
purchasing less meat as a share of total food spending generated lower GHGEs, spent less
on food, and purchased significantly lower amounts of unhealthy macronutrients and of
some essential micronutrients per average U.S. adult. Among a sample of U.S. tea
consumers there is significant interest for protecting the quality of consumable food
and beverage products from the adverse impacts of climate change and for lowering GHGEs
in agricultural production. Implications: U.S. food expenditures generate a significant
share of total U.S. emissions. Reduced purchase of meats in the U.S. can help to
mitigate GHGEs from the food supply chain while simultaneously helping U.S. consumers
potentially improve the nutritional quality of their diets and lower food costs.
However, U.S. consumers may need nutritional guidance when switching away from meat to
ensure adequate intakes of select micronutrients. The results here suggest there exists
a significant opportunity to market low emissions agricultural practices to U.S.
consumers as a means of mitigating GHGEs.
Thesis (Ph.D.)--Tufts University, 2017.
Submitted to the Dept. of Agriculture, Food and Environment.
Advisor: Sean Cash.
Committee: Parke Wilde, and Michele Ver Ploeg.
Keywords: Agriculture economics, Nutrition, and Environmental science.read less