U.S. cities vastly underestimate greenhouse gas emissions, researchers find

Dr Gurney said the errors appeared to be simple miscalculations. “I don’t think there is an attempt to systematically or intentionally underestimate the emissions,” he said. Although some cities have estimated their emissions correctly, he noted, “whether it’s just for the right reasons or for the wrong reasons, it’s hard to know.”

Dr. Gurney’s work receives funding from the National Institute of Standards and Technology, and one of the authors, Kimberly Mueller, is a scientist there. James R. Whetstone, a manager of the institute’s greenhouse gas measurement program, called the new document “an important step forward” in properly measuring cities’ greenhouse gases. “What will best serve the nation is if we have a consistent way of reporting emissions that go from the city level to the national level,” he said.

The National Institute of Standards and Technology, he noted, focuses much of its efforts on atmospheric monitoring, and so Dr Gurney’s method can help “measure the same thing in different ways.” and thus gain confidence in the results.

Previous studies by researchers at the University of Michigan, Harvard, and the federal government found that emissions of methane, another potent greenhouse gas, were also underestimated by many cities. Dr Gurney said that “both gases really should be part of this systematic approach”.

The cities’ efforts so far, Dr Gurney said, have been a laudable effort, but “they haven’t had a lot of tools to do it.” Further, he said, “Cities find it difficult to pick up trash and fill potholes, let alone keep detailed reports on their emissions.”

Reducing emissions in a city, he said, requires a thorough understanding of key issues, including highways and industries specific to traffic jams, so that authorities can take targeted action that provides the greatest benefit at the lowest cost. . Creating high occupancy vehicle lanes or express bus lanes on every highway could be wasteful; it would be better, he said, to know which road projects could do the most good.