A La Jolla researcher has found a gas popular in termite extermination has impacts on California’s contribution to greenhouse gas emissions but the gas isn’t included in the state’s emissions inventory.
UC San Diego’s Scripps Institution of Oceanography researcher Jens Muhle has co-authored a paper published April 3 in the journal Nature that revealed California leads U.S. emissions of the pesticide and greenhouse gas sulfuryl fluoride (SO2F2).
SO2F2 is mostly used for termite extermination, but also has applications in the timber and grain industries, said Muhle, an atmospheric chemist in SIO’s Geosciences Research Division.
While working on a new instrument to measure synthetic greenhouse gases, Muhle began to see a peak in a substance unknown to him, he said.
He and his team realized the substance was a fumigant and worked with a local extermination company to identify the compound as SO2F2, which appears as a significant contributor to California emissions but is unaccounted for in the California and U.S. greenhouse gas emissions inventories.
This work is one example of how atmospheric measurement-based emission estimates of greenhouse gases – and ozone-depleting substances – reveal the “shortcomings of official emission inventories and reporting requirements,” Muhle said.
“When you look at the magnitude of the SO2F2 emission and compare it with carbon dioxide or methane, it’s a small drop in the bucket,” he said.
But compared to what California has achieved in emission reductions over the last couple of years, then “it’s actually quite comparable,” Muhle added.
“At the end of the day, we’re all trying to reduce greenhouse gas emissions. … The faster, the better.”
California is the leader in SO2F2 emissions, it seems, as “there’s a lot of fumigation going on,” he said.
The levels of sulfuryl fluoride surprised Muhle, as they surpassed those found in Texas and Florida and elsewhere along the Gulf Coast.
The explanation is likely found in the termites’ location in California attics, he said, as in other parts of the country, termites tend to be subterranean “and can be easier to treat.”
“I don’t understand why California has not included this compound in the emission inventory because they’ve known about it for years,” Muhle said, adding he hopes the California Air Resource Board will include SO2F2 going forward.
Muhle also hopes the fumigation industry will work to reduce SO2F2 emissions. “It’s small in comparison to all other greenhouse gases we need to worry about, but it all adds up.”
“Greenhouse gas emissions reduction needs to be an all hands on deck effort to be successful,” he said.
