The fireworks are over, the barbecue parties are finished and people are either back at work or heading home after a remarkably busy Fourth of July weekend. Exact figures are not out yet but the American Automobile Association (AAA) projected that a record 43 million Americans hit the road since Thursday.
Some 84 percent of that holiday traveling was done in cars, according to AAA, and while a road trip is the quintessential American tradition, this one often comes with a cost to the environment. The transportation sector — that is cars, freight trucks, trains, and planes — is the second-largest source of climate change-inducing greenhouse gas emissions in the United States, encompassing about 28 percent of all emissions, according to the Environmental Protection Agency. Only the electricity sector produces more emissions, though last winter vehicle emissions surpassed the pollution from electric power plants for the first time since 1979, Climate Central reported.
It’s still unclear if that could happen again this summer, but so far this year’s holiday car travel was expected to reach an all-time high for the third time in a row. Low gas prices — the lowest since 2005 — and increased economic activity were considered the main accelerating pedals for the roughly 36 million people who flocked to the freeways. That, in turn, means millions of tailpipes were releasing noxious gases into the atmosphere in unison.
That’s an important detail not just because releasing a lot of greenhouse gases in a short amount of time is worse for global warming, but because much of it occurred while vehicles were stuck in traffic during hot, dry weather. A combination of warm and dry weather is more likely to turn emissions into polluting ground-level ozone: a major component of smog. It can also cause respiratory and cardiac problems, according to the EPA.
With more than 45 million people in the country living, working, or going to school within 300 feet of a major road, airport or railroad, having so many cars on the road is also a growing concern with regard to the health impacts of traffic. That pollution also disproportionately affects poor, non-white neighborhoods.
For perspective, cars and trucks emit around 24 pounds of CO2 and other global warming gases for every gallon of gas they burn. During the Great Recession, emissions from fuel consumption declined, but that started to change in 2010. Still, the latest figures from the U.S. Energy Information Administration (EIA) show that March emissions attributed to motor gasoline are slightly lower than a decade ago. In 2006, some 101 million metric tons of CO2 came from motor gasoline -- this March the number is less than 98 million metric tons. However, on a longer timeline, greenhouse gas emissions have been growing by about 17 percent since 1990. This historical increase largely stems from a growing demand for travel, and limited gains in fuel efficiency across the U.S. vehicle fleet, according to the EPA.
The scale of holiday travel is also an indication of a growing trend in fuel consumption that the EIA expects for this year. Motor gasoline consumption is projected to increase by 1.8 percent in 2016 after a jump of around 2.7 percent in 2015. If this rise happens, the United States will reach the highest annual average gasoline consumption on record. The previous annual average record happened in 2007, a year before the market crash that sent the auto industry into a spiraling decline.
But a growth in fuel consumption describes not just the average citizen's driving habit. Trucks traveling long distances, carrying heavy loads, are responsible for most of the annual average fuel consumption, so therefore a large portion of the sector's emissions can be attributed to the transport industry and the demand for goods driving it.
Past consumption practices are thus making a comeback. That is true for car buying, too. The economic downturn of 2008 may have led to fewer overall vehicle purchases, but that was short-lived. In fact, recent market research figures suggest vehicle purchasing increased the year after a dramatic drop in 2009, and the Washington Post reported record car sales not seen since the year 2000. In 2015, about 17.5 million cars and trucks were sold, surpassing the 17.3 million record set in 2000.
Environmental organizations promote alternatives like public transportation or biking, which help offset growing emissions, and avoid the demand for oil that increasingly comes from hydraulic fracturing. And yet, there is one upshot from new car buying that transcends the economic benefit of more of everything.
More people having new cars means more people driving lighter, more aerodynamic and efficient transportation that is more likely to be hybrid or electric, according to the EIA. That, of course, is only a true benefit for the environment if older cars stay off the road and people purchase the smaller, most efficient vehicles. In part, people are having the options to buy more efficient vehicles thanks to better Corporate Average Fuel Economy (CAFE) standards which have been successful in ramping up fuel economy for cars and light trucks. What's more, electric vehicle sales have risen since 2010.
However, sales of small passenger cars fell in 2015 while sales of light trucks and sport utility vehicles grew 13 percent. And on top of that, last year the average age of light vehicles in the United States rose slightly to 11.5 years, according to IHS Automotive, which suggests people are holding onto older vehicles that create more of the pollution choking traffic-clogged roadways across the country.