How diet and agricultural practices contribute to climate change

Editor’s note: This is the fourth in a series of columns by Joana Tavares, The Tribune’s American Association for the Advancement of Science mass media fellow, answering reader questions about climate change. Tavares is completing a doctorate degree in earth sciences at UC Irvine.

“I would like to see you share how the diet we consume contributes to climate change based on the agricultural practices of food production.” — Wendy, San Luis Obispo

Dear Wendy,

Diets are a huge deal, aren’t they? I feel like I have tried them all: low-fat, high-fat, low-carb, keto, pescatarian, vegetarian diet, you name it. I know that I’m not alone in this journey to figure out how to “eat right,” whatever that means to each person.

Deciding what to eat is such a big part of our lives, and yet most of us know so little about where our food comes from, how it is produced, or how it affects the rest of the world. This disconnect is a real problem for our health and for the health of the planet.

Most modern farms look nothing like Old MacDonald’s

There is indisputable evidence that industrial agriculture and factory farming are destroying natural ecosystems, polluting water supplies, depleting soils around the world, and producing large amounts of greenhouse gases which warm the planet and cause climate change. Globally, food production accounts for as much as 40% of all emissions from human activities.

Over the past century, unsustainable practices such as tillage, monocultures and the indiscriminate use of pesticides and fertilizers have become commonplace in the business of producing ever-increasing amounts of relatively cheap but nutritionally questionable food.

The solutions to most of these problems are grouped under the umbrella term “regenerative agriculture.” Scientists are working to determine how much these practices can deliver in terms of reducing greenhouse gas emissions, and so far the results are encouraging. Soil restoration seems to not only reduce emissions from agriculture but may also serve to remove carbon from the atmosphere and store it away, where it cannot warm the planet.

For those who want to learn more, I’d recommend watching the documentary “Kiss the Ground” and visiting the websites of various local organizations that promote sustainable farming.

• The California Climate & Agriculture Network is a coalition of farming organizations that advocate for state and federal policies to ensure the resilience of local farms and ranches in the face of climate change.
• The Cachuma Resource Conservation District promotes economically viable and environmentally sustainable farming and ranching operations.
• FOR THE LOVE OF SOIL is an independent soil science education, communication, and art organization co-founded by two female soil experts, Yamina Pressler, and Karen Vaughan.

Implementing regenerative agriculture at scale is a real challenge. Farmers, ranchers and consumers need to be educated, and lobbying by powerful corporations that want to maintain the status quo needs to be stopped. But, in general, regenerative agriculture is an idea that is easy to sell.

The conversation usually becomes awkward when we bring up the one industry associated to the largest share of greenhouse gas emissions from food production: meat and dairy.

Shaming and the meat-climate paradox

There is no definitive number for the total amount of greenhouse gasses produced by the meat and dairy industry. In 2013, the U.N.’s Food and Agriculture Organization calculated it to be 14.5% of global emissions, and experts say this number is an underestimate. The math is complex because the business is complex.

Carbon dioxide is released in all steps of the operation, from the deforestation and land clearing for pasture and feed crops, to the refrigeration needed to store and transport animal products. Then there is the infamous methane from flatulence and belching of ruminants, mainly cows and sheep, and let’s not forget manure, which releases even more methane and nitrous oxide as it decomposes.

Animal agriculture, as currently done in most of the world, is not wholesome.

Scientists estimate that, when considering greenhouse gas emissions from diets alone, meat-eaters are responsible for almost twice as much emissions as vegetarians, and about two and a half times as much as vegans.

Considering all this information, what I am about to say next may be paradoxical, but here it goes: In my opinion, we should not be telling people that they must stop eating meat and dairy.

Although veganism is becoming more popular, not everybody is ready or able to fully transition into a plant-based diet. People have all sorts of cultural, ideological and health reasons to continue eating meat, and pushing for total veganism as an “obligatory sacrifice” will alienate many folks that we desperately need to engage in the climate movement.

Centering the climate action conversation on people’s diets can also deflect attention from more urgent societal changes, such as the banning of fossil fuels. Climate shaming — including food shaming — is a strategy used by fossil fuel interests to cause division within the climate movement and corrode its bargaining power.

Switching to a plant-based diet is a great start, but to solve the climate crisis we need to change systems. We need to be fighting in unison for immediate governmental actions that reduce emissions from all sectors: electricity and heat production, industry, transportation, building, and yes, agriculture and land use too.

A good compromise would be to ask people to reduce their consumption of animal products and to offer practical alternatives and cultural context that facilitate their choices. Initiatives like Meatless Monday, Veganuary and VegFests are creative ways to build community around the cause because they transform “personal sacrifice” into fun social experiences.

Why not invite friends and family to try some vegan food this weekend? Here are some restaurants that serve plant-based meals:

Low-hanging fruits

Another problem is how wasteful food production currently is in all its aspects.

Approximately one third of the food produced on the planet goes to waste. Most food (70-80%) is lost before it reaches consumers, but food wasted by households can be significant in developed countries.

Food waste is responsible for 8-10% of global greenhouse gas emissions. This estimate accounts only for the emissions that went into producing the food. The methane that is released when this food ends up decaying in landfills is a double-whammy.

To combat food waste at home, we should better plan meals and shopping, and then separate food scrapings and organic materials for composting. California recently passed a law requiring that food waste be discarded in the green bins rather than the trash.

Residents of SLO County can also rely on the Hitachi-Zosen anaerobic digestor, a first of its kind in the U.S. This technology makes it possible to convert all kinds of organic waste, including meat, dairy and fat, into all-natural fertilizer and biogas. The biogas is then used as renewable fuel for generating electricity, which is fed into the San Luis Obispo region’s electrical grid. The plant produces enough energy to power around 600 homes, and serves as a good example that systems can be improved.

As I admitted earlier, I have personally struggled with my diet for many years. I grew up in the countryside of Brazil hunting, fishing, and raising animals for food, and I’d be lying if I told you that it has been easy for me to transition to a plant-based diet.

Nowadays, I eat very few animal products, I don’t eat beef, and I try to buy locally grown food. It took reeducation and reevaluation of my mental models to let go of some beliefs about nutrition that I now realize were flawed. And I am still a sucker for cheese.

The way I see it, there are many paths into sustainable living, and I hope we can all continue learning and working together to implement solutions for this global existential crisis.

The author would like to thank Wendy Fertschneider, R.D., retired public health nutritionist, County of San Luis Obispo, and Erin Pearce, PhD, Cal Poly SLO professor and director of the Initiative for Climate Leadership and Resilience, for their contributions to this article.