Carbon Offsets Take Flight

Many airlines now offer passengers the option of compensating for carbon emissions via tree-planting and other programs. Should they just fly less?

By Pallavi Gogoi

For as little as $2, an eco-conscious passenger flying on Continental Airlines (CAL) can cancel out the damage they may be doing to the ozone layer. That's how much it costs to purchase a "carbon offset" to pay for planting trees. Or, they can contribute $50 or more toward a renewable-energy project such as solar or wind power. Both options are provided to passengers when they book through the airline's Web site. "Our customers tell us they want to minimize their impact on the environment, and we want to give them the tools," says Leah Raney, managing director of global environmental affairs for Continental.

A whole host of airlines, including Continental and Delta Air Lines (DAL) in the U.S. and Virgin Atlantic, Lufthansa, and Qantas internationally, are offering customers ways to offset their contribution to carbon dioxide emissions when they fly. And why not? Reducing one's carbon footprint seems to be de rigueur these days.

Last year, Vatican City accepted an offer to plant trees in a Hungarian national park, making it the only "carbon-neutral" state. "In the last eight months Delta passengers have bought offsets that paid for us to plant 102,000 trees," says Jena Thompson, director for the Go Zero program at the Conservation Fund, an Arlington (Va.) nonprofit whose primary objective is land protection. The group manages Delta's carbon offsets program. "Those trees will suck up 64,000 tons of carbon dioxide in their lifetime, which equals what would be produced by 2,900 Americans in a year."

Sounds simple and high-minded. But these programs are actually quite complex, and the payoff is being questioned by a growing number of people.

Codes of Standards

As the demand to reduce carbon footprints grows, many largely unregulated companies have sprung up to offer carbon offsets. These companies in turn plant trees in forests or algae in oceans, or invest in wind and solar power plants. Critics point out it is difficult to tell exactly the quality of work these companies perform. "The quality and standards of voluntary offset companies vary widely," wrote Anja Kollmuss and Benjamin Bowell in a report about offsets for the Tufts [University] Climate Initiative. The authors also noted some of the companies that sell offsets might see it as a way to promote their own environmental or humanitarian missions, and as "a financial opportunity."

No wonder, then, that several codes of standards have emerged. One of them is the Voluntary Carbon Standard, launched in November. It offers quality assurance checks from the Climate Group, the International Emissions Trading Assn., and the World Business Council for Sustainable Development. There are at least three other international standards including the Gold Standard, a Swiss nonprofit backed by several environmental groups that offers a quality label to offset projects such as renewable energy.

"Whim of Nature"

It is also difficult to judge the actual benefit produced by carbon offset companies. Take tree planting, for instance. It works in theory because trees absorb carbon dioxide from the atmosphere—including, presumably, that which is spewed from jet engines. However, environmental experts point out that trees absorb carbon at different rates depending on whether they are planted in temperate or tropical climate zones. Besides, they are susceptible to disease and natural disasters, and if they don't last their lifetime they aren't offsetting the carbon people pay for.