Social distancing mitigations put U.S. on track to meet goals of Paris Climate Accord
As individuals across the country slow down their lives and practice social distancing, they are driving less, flying less and using less public transportation. Since early March, car travel has reduced by billions of miles, greenhouse gas emissions have decreased by millions of metric tons and fuel-tax revenue reductions have resulted in states losing millions of dollars, according to the latest special report from the Road Ecology Center.
The Road Ecology Center released two reports regarding the impacts of COVID-19. Their first report, “Impact of COVID-19 on California Traffic Crashes,” was released on April 1 and focused on how traffic reductions have led to fewer car crashes, according to Fraser Shilling, the director of the Road Ecology Center. Researchers then investigated the additional benefits of reduced traffic, leading to the next report, “Impact of COVID19 Mitigation on Traffic, Fuel Use and Climate Change,” published on April 30.
“For America, I strongly believe that the pandemic has brought a huge, huge construction to transportation, which most likely will not only act as a temporary effect,” said Giovanni Circella, the director of the Three Revolutions Future Mobility Program at UC Davis.
Using data from Streetlight.com, the Road Ecology Center researchers estimated the changes in vehicle miles traveled across the U.S. each day from before and after the shelter-in-place guidelines were enacted. From early March to the second week of April, vehicle miles dropped from 103 billion miles to 29 billion miles. Across all states, travel by vehicle reduced by at least 60%, according to the report.
The report also noted a correlation between a state’s quantity of COVID-19 cases and their reductions in traffic. People drove fewer miles in states with higher reports of infection cases and death. During the reporting period, New York had the highest case rate. Drivers in New York and surrounding states drove at least 80% fewer miles.
Reductions in travel caused fuel use to drop from 4.6 billion gallons to 1.3 billion gallons from early March to mid April. Overall, drivers saved $8.6 billion per week. These cutbacks in driving have had major impacts on the economy, especially in California, Shilling said.
“In California we’ve created an economic system that’s very dependent on people’s driving vehicles, and to suddenly not drive can have big effects on the functioning of that economic system,” Shilling said.
Driving less also results in lower fuel-tax revenues, which vary by state. In California, vehicle miles dropped more than 75%, causing state fuel tax revenue to plummet from $61 million to $15 million during the reporting period.
“It’s probably going to result in billions of dollars of reduced tax revenue from just the sale of gasoline and diesel, so that’s a big deal,” Shilling said. “It’s a big deal for the consumer, because we must pay for gas and it’s a big deal for the states because then they’re getting less sales tax money.”
For an eight week stay-at-home order, states lose an estimated $370 million, which normally supports public transportation improvements aimed at reducing emissions, highway construction and maintenance, according to the report.
“The fuel tax reduction has a ripple effect through the economy,” Shilling said.
Additionally, less individuals have been using public transportation, threatening their financial wellbeing, said Susan Handy, a professor in the department of environmental science and policy. Her advice for those looking for transportation that is social-distancing and environmentally friendly is biking, especially in Davis.
“To what degree [public transportation] will be able to maintain good service is a big question,” Handy said. “There’s a concern that this will have less transit ridership than before, and that would be a bad thing from an environmental standpoint.”
Overall, reductions in transportation have lowered greenhouse gas emissions, placing the nation closer to Paris Climate Accord goals. The report’s authors noted a 71% decline in carbon dioxide emissions from local road travel across the U.S. For all of 2020, this represents a 13% decrease in transportation-related annual emissions and a 4% decrease in total emissions.
“If there’s less fuel being bought and burned in our vehicles, we’re producing less greenhouse gas emissions,” Shilling said.
In 2015, the U.S. committed to the Paris Climate Accord agreement by agreeing to reduce greenhouse gas emissions by 2.5% per year. Due to reductions in emissions over the past two months, the U.S. has already exceeded the annual commitment. While the U.S. was formally able to withdraw from the Paris agreement on Nov. 4, 2019, the notice, and thus the final withdrawal, does not become official until a year later.
“If a stay-at-home guidance continues, if people continue to drive less during this year, then we will greatly exceed our commitment,” Shilling said. “This is what it feels like to follow the Paris Climate Accord.”
Other than greatly reducing driving over a small two month window, there are other ways to meet the Paris Climate Accord. If people reduced their driving by 10% per day, per month, or across the whole year, or if vehicle fuel efficiency increased by 5 to 10% per year, then the targets would be met, Shilling said.
Learning to change one’s behavior to drive less is the most important lesson to take away from the report, Shilling said. These lessons can be applied to help the U.S. meet the greenhouse gas emission targets after stay-at-home orders are lifted.
“A lot of people are suffering economic consequences and many people are suffering from health conditions, but at least the planet can breathe, and has been breathing for 10 weeks,” Circella said.
Due to major changes in greenhouse gas emissions, Shilling predicts a stalling in the global temperature increase causing climate change.
“There’s such a high rate of greenhouse gas introduction into the atmosphere that if you suddenly slow it down by half, at some point, you’re going to have a slowing down of the rate of climate change,” Shilling said.
The study acknowledges that emission benefits of the stay-at-home order could go away once normal activity resumes. Shilling predicts that the shelter-in-place restrictions for the coming months will be less strict, causing driving to increase. In California, instead of the 75% reduction in driving that was witnessed in the reporting period, Shilling believes these values will oscillate between 25 and 50%.
“The big question is, ‘What’s going to happen as the restrictions are lifted?’” Handy said. “‘Are people going to go back to their old ways?’ Some of the current data shows that driving is starting to increase again. It’s still less than it was, but it is likely to trend back upward.”
As the tight grip of shelter-in-place restrictions begin to loosen, individuals must learn to disconnect economic well-being from driving in order to continue the decline in greenhouse gas emissions, Shilling said.
“There’s going to be a huge political pushback against trying to do climate change policy, when people realize, ‘Oh, if we do that, we’re not going to have a job,’” Shilling said. “The short term benefits of having a job will outweigh the seeming long term benefits of having a planet.”
Written by: Margo Rosenbaum — science@theaggie.org
