You may think that all that driving you do, or air conditioning your house, is your biggest contribution you make to global warming. But how about all those air miles?
For many people reading this, air travel is their most serious environmental sin. One round-trip flight from New York to Europe or to San Francisco creates about 2 or 3 tons of carbon dioxide per person. The average American generates about 19 tons of carbon dioxide a year; the average European, 10.
So if you take five long flights a year, they may well account for three-quarters of the emissions you create. “For many people in New York City, who don’t drive much and live in apartments, this is probably going to be by far the largest part of their carbon footprint,” says Anja Kollmuss, a Zurich-based environmental consultant.
It is for me. And for people like Al Gore or Richard Branson who crisscross the world, often by private jet, proclaiming their devotion to the environment.
Though air travel emissions now account for only about 5 percent of warming, that fraction is projected to rise significantly, since the volume of air travel is increasing much faster than gains in flight fuel efficiency. (Also, emissions from most other sectors are falling.)
Tax carbon at $20 a ton, which is roughly the tax that many economists believe would be required to have an impact on human behavior adequate to slow warming, and suddenly you will understand how big a climate change driver air travel is. And you will also think more carefully about how often, and how far, you fly.
Another alternative is to sell carbon offsets along with air travel tickets.