University of California Reveals Significant Impact of Food Systems on Greenhouse Gas Emissions

Food systems contribute to nearly 30 percent of greenhouse gas emissions (GHGE) yet are rarely included in climate change mitigation policies. Since 2013, the ten campuses of the University of California have been finding ways to reduce greenhouse gas emissions through their Carbon Neutrality Initiative.

The case study of integrating climate and food policies in higher education was published this year in the journal Climate Policy. "The UC is a leader in climate and food research, and has major policy initiatives for mitigating climate change and for promoting healthy, sustainable food systems," wrote the authors.

The initiative covers three scopes of GHGE. Scope 1 involves mitigating campus-generated emissions from sources like campus vehicles. Scope 2 covers purchased energy causing indirect emissions on campus.

The third scope is indirect emissions from food systems. The UC's target for 2025 is to reduce emissions by 42 to 55 percent. The research has "implications for broader climate policy in terms of food systems' high GHGE, the health, environmental, economic and social benefits of food system changes, and ways these changes could be implemented."

Professor David Cleveland from the Santa Barbara campus said that food has a major impact on the climate. The majority of food system GHGE comes from animal-source foods.

Greenhouse Gas Emissions from Food Systems

According to Our World in Data, food emissions fall into the four categories of livestock and fisheries, crop production, land use, and supply chains. Cattle produce a significant amount of methane while maintaining livestock involves pasture and manure management. Fishing vessels, similar to vehicles, burn fuel, releasing pollutants in the atmosphere.

Crop production for both humans and animals cause emissions via fertilizers containing nitrous oxide. Rice production emits methane while agricultural machinery emits carbon dioxide.

Land use also has a significant impact as clearing land is often burned. Converting ecosystems such as forests mean the loss of natural "carbon sinks," where trees absorb nearly 30 percent of carbon.
Lastly, supply chains account for emissions from transportation, processing, and packaging fo food.

Achieving Reduced GHGE On Campus

Cleveland said that shifting to plant-based food and reducing food waste can reduce GHGE. "It's low-hanging fruit," he said. Changing the food system can be accomplished inexpensively, unlike large investments in converting to natural gas or changing energy sources on the campuses.

"The fundamental thing is that animals eat plants," Cleveland said, explaining the importance of understanding how food production and resources impact GHGE. Animals require a lot of energy and resources to maintain such as land, water, and grains. It would be more efficient to eat plants directly.

It's not about going vegan or vegetarian, explained Cleveland, but rather, "moving toward diets that are more climate-friendly." For example, chicken has a smaller carbon footprint than beef and lamb. Reducing food waste, which contributes to over three billion tons of carbon gas emissions, would also make a significant impact.

Small changes can be done across all campuses such as vegetarian options as default menu items or offering plant-based alternatives to red meat. Climate-friendly food can be healthy, "delicious and more socially equitable than more climate-damaging food," said Cleveland.

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