A recent study led by Johns Hopkins University has found that California, despite its aggressive greenhouse gas reduction policies, is the largest emitter of sulfuryl fluoride in the United States. This gas, commonly used as a pesticide for treating termites and wood-infesting insects, accounts for up to 17% of global emissions, with the majority of emissions in the U.S. originating from just a few counties in California. The researchers analyzed over 15,000 air samples collected between 2015 and 2019 to trace the emissions back to their source, primarily in Los Angeles, Orange, and San Diego counties.
The team discovered that 60-85% of sulfuryl fluoride emissions in the U.S. are coming from California, despite the state’s efforts to reduce greenhouse gas emissions. This finding is crucial for achieving net-zero emissions by 2045, as California has committed to in its comprehensive plan. Sulfuryl fluoride, which stays in the atmosphere for over 40 years, contributes to global warming by trapping heat and sending it back to the Earth’s surface. While efforts typically focus on reducing carbon emissions, researchers emphasize the importance of addressing other greenhouse gases like sulfuryl fluoride to combat climate change effectively.
The researchers attribute the majority of California’s sulfuryl fluoride emissions to structural fumigation practices, where gas is pumped into an airtight tent to eradicate pests and then vented into the atmosphere afterward. Additionally, roughly 15% of emissions come from agricultural and commodities fumigation. Despite being less harmful than banned fumigants, sulfuryl fluoride still contributes to global warming, making it essential for California to address these emissions to achieve its greenhouse gas reduction goals. The researchers have shared their findings with the California Air Resources Board and the Bay Area Air Quality Management District to inform future mitigation strategies.
Sulfuryl fluoride was first approved as a pesticide in 1959 after countries phased out ozone-depleting fumigants, making it a popular choice for pest control. The gas is essential for eliminating drywood termites and preventing pests from spreading through shipping ports. However, its long-term presence in the atmosphere poses a significant threat to global warming, as humans have been emitting sulfuryl fluoride at a rate faster than it can naturally break down. As California continues to lead in reducing greenhouse gas emissions, addressing sulfuryl fluoride emissions will be key to achieving net-zero emissions by 2045.
The researchers stressed the importance of fully understanding and addressing all greenhouse gases, including sulfuryl fluoride, to effectively combat climate change. By identifying the sources and impacts of these emissions, California can develop holistic strategies to reduce its greenhouse gas footprint. The study was possible due to funding from the NSF, NOAA, and NASA, highlighting the collaborative efforts necessary to address complex environmental issues. Overall, this research sheds light on the overlooked impact of sulfuryl fluoride emissions in California and underscores the importance of addressing all greenhouse gases to achieve sustainable environmental goals.
