How many times have you heard that it's cheaper to fly than drive? The extraordinary growth of airline travel in the last twenty years is often touted as a modern miracle of globalization, but it's looking more and more like the blowback may be the impacts of air travel on greenhouse gas emissions. Although the airline ticket might be cheap, jet travel releases more than 660 million tons of carbon dioxide into the atmosphere each year.
Hopefully, it won't surprise you to learn that hurtling through the air in a large metal object burns a lot of fuel -- the average round trip between New York and Los Angeles produces about two tons of carbon dioxide per passenger. The problem is where it ends up. Planes fly high because it's more efficient (good) but at that altitude CO2 tends to stay put longer and, along with the nitrogen oxides and water vapor released by jet engines, have a greater warming impact (bad). In addition, contrails (those white trails left by planes) are also believed to have a warming effect, both by themselves and by spurring the formation of high cirrus clouds that trap even more of the Earth's heat.
Scientists estimate that aircraft already cause about 3.5% of human-caused global warming. But the pace of growth in this industry worldwide is going to push this up continuously. Since 1960, air travel has been expanding at a rate 2.5 times greater than economic growth. Air travel is projected to nearly double just in the next 15 years. As a result, greenhouse gas emissions from airplanes might be responsible for up to 15% of the human-induced warming within 50 years.
The industry is working on the problem. Research programs in the US and Europe could cut emissions from future jets by 20 to 40%. Virgin Atlantic is experimenting with towing planes in the current fleet to the runway, saving as much as two tons of fuel per flight. Unfortunately, these improvements will not offset the projected growth in travel.
In some parts of the US rail service is frequent, reliable, and has conveniently located stations. In the northeast corridor, in particular, taking the train can be a real time-saver. High speed rail routes are under consideration in California and the Midwest, so be sure to show your support.
When you fly overseas remember that many other parts of the world -- Europe, Japan, and India among them -- have excellent rail coverage, so be sure to explore train routes before hopping on a short flight.
Still another option is to save the time and cost of flying by staying closer to home base. If it's a business trip, perhaps a teleconference or another virtual tool will suffice? If you're planning a vacation, there may be destinations full of adventure just over the next ridge. Investing in local economies is one important part of the long-term strategy for addressing climate change, and you can help by spending your tourist dollar in nearby communities.
When you decide to fly, consider buying carbon offsets; it might add only a few dollars to the cost of your plane ticket.
