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AAAS Member Jennifer Jay Knows the Carbon Impact of Your Thanksgiving Meal

Jennifer Jay
Jennifer Jay, Ph.D. Photo by Oszie Tarula.

As the country lays out its Thanksgiving tables, AAAS Member Jennifer Jay, Ph.D., is focused on studying the carbon impact of how we eat.

“Food is the single best lever that we have for improving our relationship with the environment,” says Jay, a Professor in the Civil and Environmental Engineering Department at the University of California, Los Angeles. “It’s a major driver in the way we interact with the planet.  Our diet not only impacts the climate but a whole range of environmental issues including biodiversity loss, nutrient pollution, water use, and proliferation of antibiotic resistance in the environment.”

High-carbon footprint proteins like beef, lamb and dairy, versus low-carbon-footprint proteins, for example, peanuts and beans, is one area that Jay studies. Over the years, Jay has developed elaborate graphs and calculations that show how a plant-based diet has a lower carbon footprint than say meat or poultry.  

“Why would that be?” she asks. “Because whenever you are making meat, it requires crops, transport, land, water, pesticides and nutrients.”

Jay points to Thanksgiving dinners as one example. The typical dinner eaten by an American family, with turkey and dressing, has a lower carbon footprint than a meal where beef is served. One slice of a turkey weighing approximately 28.35g has a carbon footprint of 143g. On the other hand, a hamburger has a carbon footprint of 2,645g. And while not the standard Thanksgiving fare, another American staple, the peanut butter and jelly sandwich, comes in at 150-200 grams of carbon.

Beef and dairy, she argues, require more resources to produce than poultry or peanuts, and if we were to make any changes in our lifestyles that would impact the health of the planet, we would have to start by making simple changes to our diet. “Even if you are having a turkey dinner, you can leave out dairy in your food,” she suggests. 

Jay’s experience in teaching has shown her how people are able to make decisions about food easier when there are quantitative measures. That concept and thought process propelled her to start a non-profit initiative called Meals for the Planet in 2017, which comes complete with an online blog that shares both recipes and sustainability tips and tricks.

“I started really for the fun of it doing calculations on some recipes and I just found numbers really engaging,” she says.  

Jay’s lab at UCLA is not only focused on food and the carbon footprint that comes with eating, but it is also heavily involved in antibiotic resistance work. Through her Surfer Resistance Project, Jay has been tracking the “superbugs” Methicillin-Resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE), which are categorized as serious threats by the U.S. Centers for Disease Control and Prevention.

To better understand these superbugs, also known as antibiotic-resistant bacteria (ARB), Jay and her colleagues have been swabbing nasal cavities of people who have been using coastal waters for recreation. This means getting up close and personal with surfers as they hang ten.

The reason the nasal cavities of surfers are so ideal is that during winter, when storms are frequent and water quality is poor because of urban storm contaminants, surfers naturally go into environments where more ARB may be present. In turn, they provide an ideal population for evaluating the relationship between ARB and antibiotic-resistance genes (ARG). The data collected will help explain how infections due to environmental exposure of an antibiotic-resistant organism happen.

“We are actually testing surfers' noses out on Venice Beach and comparing what we see in the noses to what we see in the water,” she says. “Our next step is to use molecular techniques to compare and figure out where the organisms are coming from.”

The origin of the antibiotic-resistant bacteria is still a puzzle her lab is trying to solve.

“We do know that manure-based fertilizers do carry a lot of antibiotic resistance genes,” she says. Stormwater mops up these bacteria from lawns across California and washes it into the ocean—something that Jay suspects might be the source of the superbugs found in coastal waters. “We know from monitoring the oceans that we see bacteria at lower levels, but when it rains, we see a huge spike.”

It is not antibiotic-resistant bacteria or an extended carbon footprint from our diets that keep Jay, a mom with twins, awake at night. Her biggest concern is the ongoing threat of climate change to our planet.

“It has a very human face for me, so I don’t think about it as a thing in the abstract at all,” she says. “People are being impacted and suffering and losing people they love because of climate change. That one gets me.”

The safe operating space for humanity, a diagram that identifies and quantifies planetary boundaries, such as climatic, geophysical, atmospheric and ecological processes that must not be broken, is the North Star that Jay uses not just in her life but in her teaching and research activities.

“It is kind of an inspiration for me because all the different environmental issues we care about are kind of conceptualized in this diagram,” she says.


Owen Kibenge