Fertilizer is fouling the air in California: Study
brewbooks/flickr

Fertilizer is fouling the air in California: Study

Due to heavy fertilizer use, California's Central Valley is behind up to 41 percent of the state's emissions of nitrogen oxide—an air pollutant and climate-warming gas

A large proportion of California's nitrogen oxide—which can cause harmful ozone and a variety of health impacts—comes from heavy fertilizer use in the state's Central Valley, according to a new study.


University of California, Davis, researchers reported today that as much as 41 percent of smog-causing nitrogen oxide emissions are coming from the state's Central Valley region, which grows more than half of US vegetables, fruits and nuts.

"The effect of large soil NOx emissions on air quality and human health remain unclear, but the magnitude of the flux alone raises concern about its potential impact, particularly in rural California," the authors wrote in the study published today in Science Advances journal.

Nitrogen oxides, a "family of air-polluting compounds," according to the study, are also pumped into the air via burning fossil fuels and car exhaust.

The pollutants spur ground level ozone, have been linked to asthma, other breathing problems and heart disease, and are a potent greenhouse gas. One pound of nitrous oxide—a common component of nitrogen oxide—has 300 times more climate warming impact than a pound of carbon dioxide, according to the U.S. Environmental Protection Agency.

The scientists collected data from flights over the farming region and analyzed it along with computer models.

They estimated between 25 percent and 41 percent of the state nitrogen oxide emissions come from farm soils that received nitrogen-based fertilizers.


Credit: UC Davis

The fertilizers simulate soil microbes that can convert nitrogen, an essential plant nutrient, to nitrogen oxide.

About half of nitrogen-based fertilizers put on crops are actually absorbed by plants.

The study built upon 2012 research from the university that reported, since 1750, nitrous oxide levels have increased 20 percent, largely due to heavy fertilizer use over the past 50 years.

The authors didn't vilify fertilizers. "We need to increase the food we're making," said lead author Maya Almaraz, a postdoctoral fellow at UC Davis, in a statement. "We need to do it on the land we have. But we need to do it using improved techniques."

Almaraz and colleagues pointed to potential solutions, including slow-release fertilizers that reduce emissions, healthy soil efforts to bolster crops' uptake and retention of nutrients, and precision agriculture, which would mean more discriminate fertilizer application.

"It's critical that new policies focus on incentives to bring the latest nutrient management technologies to farms so that growers can produce food more efficiently, increasing their bottom line and improving rural health," said senior author Ben Houlton, a professor with the UC Davis Department of Land, Air and Water Resources, and director of the John Muir Institute of the Environment, in a statement.

Op-ed: Ripe for disaster declarations — heat, wildfire smoke and death data

Currently, the federal data on extreme heat and wildfire smoke itself constitutes a major disaster.

Extreme heat and wildfire smoke should of course be defined as major disasters by the Federal Emergency Management Agency. According to the National Weather Service, heat kills more people in this nation than hurricanes, tornadoes, floods, and lightning combined.
Keep reading...Show less
Senator Whitehouse & climate change

Senator Whitehouse puts climate change on budget committee’s agenda

For more than a decade, Senator Sheldon Whitehouse gave daily warnings about the mounting threat of climate change. Now he has a powerful new perch.
Amid LNG’s Gulf Coast expansion, community hopes to stand in its way
Coast Guard inspects Cameron LNG Facility in preparation for first LNG export in 2019. (Credit: Coast Guard News)

Amid LNG’s Gulf Coast expansion, community hopes to stand in its way

This 2-part series was co-produced by Environmental Health News and the journalism non-profit Economic Hardship Reporting Project. See part 1 here.Este ensayo también está disponible en español
Keep reading...Show less

Wildfire smoke impacts air quality in parts of Canada and western US

Smoke from wildfires across several western US states and Canada has led to air quality alerts in affected regions.

Dorany Pineda reports for The Associated Press.

Keep reading...Show less
uk climate tree species
Credit: RdA Suisse/Flickr

London's Royal Botanical Gardens faces major tree loss due to climate change

Kew Gardens could lose over half of its tree species by 2090 due to climate change, a new study warns.

Helena Horton reports for The Guardian.

Keep reading...Show less

Supreme Court considers halting Biden's EPA climate rule

The Supreme Court may undermine the U.S. Environmental Protection Agency's latest rule on emissions from power plants, following challenges from conservative states and industry groups.

Niina H. Farah reports for E&E News.

Keep reading...Show less
Kamala Harris Environmental Justice
Credit: NASA HQ PHOTO/Flickr

Harris could expand environmental justice efforts as president

Vice President Kamala Harris aims to amplify environmental justice initiatives if she becomes president, building on the Biden administration's legacy of supporting marginalized communities impacted by pollution.

Kevin Bogardus reports for E&E News.

Keep reading...Show less

Millions of Californians face wildfire risks near oil wells

Millions of Californians live near oil and gas wells that are increasingly in the path of wildfires, raising concerns about explosions, pollution and infrastructure damage.

Hayley Smith reports for Los Angeles Times.

Keep reading...Show less
From our Newsroom
pennsylvania fracking

Living near oil and gas operations linked to worse mental health in people hoping to become pregnant

“If we’re concerned about healthy pregnancies, focusing on the period before pregnancy may be even more important.”

climate change flooding

Op-ed: The climate crisis demands a move away from car dependency

Power shutoffs or wildfire evacuations can be deadly for disabled people, especially nondrivers who may not have a way to get to a cooling center or evacuation point.

joe biden

Biden administration unveils plan to wean US government off single-use plastics

“Because of its purchasing power … the Federal Government has the potential to significantly impact the supply of these products.”

chemical recycling

Chemical recycling has an economic and environmental injustice problem: Report

“It wouldn’t even make a dent in the amount of plastic pollution out there.”

carbon capture

30 environmental advocacy groups ask PA governor to veto carbon capture bill

“Putting resources toward carbon capture and storage instead of renewable energy is wasting time we don’t have.”

Stay informed: sign up for The Daily Climate newsletter
Top news on climate impacts, solutions, politics, drivers. Delivered to your inbox week days.