Traveling in general has gotten a bad rap for its negative effects on the environment. Yet, when people discuss climate change, the discussion usually centers on cars and the large amounts of carbon emissions they release into the atmosphere. However, to fully explore the causes of climate change, one must also consider emissions from airplanes.
Some scientists estimate that a single transatlantic flight emits roughly the same amount of carbon emissions as a car would produce during one year of driving. These emissions can remain in the atmosphere for thousands of years, contributing to a slow but dangerous climate change effect. In fact, some believe that in the next five years airplanes could conceivably account for more climate change than all the cars in the world. In addition to releasing greenhouse gases, traveling by air creates another set of problems, including vapor trails and ozone, which also contribute to atmospheric warming.
So, which is a greener mode of transportation: planes or cars?
Is Air Travel Really That Bad?
While planes undoubtedly release carbon emissions and other harmful substances into the atmosphere, some argue that airlines are also naturally focused on energy efficiency. According to Boeing, the world’s largest aircraft manufacturer, a 1 percent improvement in fuel efficiency can translate to about $1 million in fuel savings over the course of 25 years (the average lifespan of a single-aisle plane).
Most major airlines are committed to keeping costs down in order to attract customers and remain viable. To do so, airlines are continuously experimenting with technologies, including alternative fuels, designed to improve fuel efficiency. United Airlines, for example, has indicated that it may begin to use fuel partially composed of farm waste to increase sustainability. In addition to making their aircraft more fuel efficient, many airlines have also experimented with the design of their planes to reduce drag and make them lighter so that they use less fuel overall.
In 2016, the Obama administration proposed a regulation that would designate plane emissions as a danger to human health and reward airlines for their efforts toward achieving fuel efficiency. This initiative, the first of its kind governing fuel standards for airplanes, would further incentivize airlines to reduce their fuel use.
Air Travel by the Numbers
The US aviation industry produces about 11 percent of the nation’s total transportation-related emissions and between 2 and 3 percent of global emissions. Moreover, the FAA indicates that the country’s demand for air travel is expected to increase dramatically over the next decade, with numbers exceeding 1 billion passengers on domestic carriers by 2029.
There isn’t much difference between an airplane and a car in terms of carbon dioxide output. In fact, according to research conducted by the US Energy Information Administration, jet fuel produces about 21.1 pounds of CO2 per gallon, while car fuel produces about 19.6 pounds per gallon. Planes often waste fuel while idling on the runway, but it has been shown that longer flights are very fuel-efficient because the aircraft remain at cruising altitude for greater periods of time.
Flying or Driving?
People have long debated whether flying or driving is the better option in terms of environmental impact. There are a variety of web calculators that can help consumers make the most environmentally conscious choice when traveling, but even with these tools, the answer is not always clear.
While air travel may initially seem like the greener option, it’s very difficult to compare the two options. Fuel efficiency data for US passenger planes is calculated for an average trip, which would be about 900 miles, versus an average car trip, which is about 9 miles. Looking at it this way, it would seem that the person traveling in the car consumes more energy per mile per passenger than the person who is flying. However, it is difficult to make this comparison because even short plane trips travel hundreds of miles versus the short distances most people travel their cars.
When considering the environmental impact of driving, one must also consider that the carbon-heavy processes involved in maintaining the nation’s roads. Additionally, even though there are more fuel-efficient cars, including hybrid vehicles or zero emissions vehicles, on the road than ever before, these vehicles remain far outnumbered by standard gasoline-powered cars.
While it is hard to say whether or not air travel is worse for the environment than ground transportation is, both have contributed in major ways to the climate change crisis. Anything that generates methane, nitrous oxide, or CO2 greenhouse gases should be viewed as dangerous; therefore, we should continue exploring greener modes of travel.