School's out, and many people who diligently bike or take the bus to work have bought their plane tickets for vacation. They may not know or care that flying will dramatically increase their carbon footprint. Using a kind of "moral accounting," people who thriftily save fuel getting to work may feel they've done "their fair share" and can indulge themselves in their time off, says a Norwegian study titled, "Troublesome Leisure Travel."
This is the unintended side effect of building compact cities, promoting environmental awareness and telecommuting — three of the most common policies for reducing carbon dioxide emissions in transportation. People living in dense cities with no backyards typically consume more energy on their time off than people in cities with a little more greenery because they undertake longer getaways by car and by plane. It's called "compensatory travel." Environmentalists who drive less during the week tend to fly more on holidays than the less environmentally active. And the Internet, while allowing people to work at home, is promoting cheap weekend getaways — by plane.
"Thus, while green individuals strive to act in an environmentally responsible manner in their everyday lives, they seem to have a conflicting need to cast aside their environmental concerns when traveling for leisure," the study says.
As the population of the developed world ages, more people will have the time, the means and the desire to fly to far-off places. Researchers Erling Holden and Kristin Linnerud urge policymakers to tax CO2 emissions for all modes of transportation, including aviation, to limit the density of cities and to spread the word about the environmental consequences of flying.