In the late Middle Ages, professional pardoners sold indulgences to Roman Catholic parishioners with the promise that their sins would be forgiven. It was one of the practices that led to the success of Martin Luther's Reformation.
Today, some environmentally conscious people purchase so-called carbon offsets to compensate for the CO2 emissions they are personally responsible for. They aim to negate the effect of the CO2 generated by their activities by investing in projects that will remove or prevent the equivalent amount of CO2 from being released to the atmosphere-such as wind and solar developments, reforestation schemes, cleaning up inefficient industries, even funding energy-efficient stoves in Nicaragua. Their motives may be good, but their means may do little to absolve them from their environmental transgressions.
Purchasing carbon offsets is hardly a fringe activity. For example, U.K. Prime Minister Tony Blair recently paid £90 to compensate for the CO2 generated during his family's flight to Florida for a Christmas holiday. The Presbyterian Church is urging its members to reduce the amount of CO2 produced by their automobiles, home heating, electricity use, and air travel and to compensate for unavoidable emissions by purchasing offsets. At least 50 companies sell offsets for air travel for between $5 and $30 per ton of CO2. Some of them sell offsets for other activities as well.
Climate Trust, a nonprofit organization in Portland, Ore., calculates personal emissions and sells offsets at $12 per ton of CO2. Through this firm, average U.S. residents supposedly can compensate for their emissions for about $200 per year. Carbonfund.org, a nonprofit group based in Silver Spring, Md., estimates that typical Americans can neutralize their carbon footprints for $99 each.
Per capita emissions in the U.S. are higher than in almost any other country. Investing just $99 sounds like a cheap, easy way to compensate for one's contribution to climate change. What is wrong with this picture?
In principle, carbon offsets could support many worthy projects. But in fact, carbon-offset firms are operating in a totally unregulated, "Wild West" environment. They are using widely disparate methods to calculate personal emissions, and they are charging vastly different prices to compensate for a ton of CO2. And the projects these firms support vary from some that may have real, verified benefits for the environment to others that have negligible or even negative impacts.
The Tufts Climate Initiative at Tufts University recently critiqued 13 companies that are offering carbon offsets and found some serious problems with many of the projects they support. One problem is termed "additionality." If a project would have happened anyway, even if its carbon offsets could not be sold, then the project is not really removing additional CO2.
Another problem with offset projects is double counting. Sometimes offsets from the same project are sold twice. Independent outside verification of carbon-offset projects is important to ensure that they are real and additional and that the reductions are measured by internationally recognized criteria, the Tufts study says.
But with forestry projects, which are the most common types of carbon-offset schemes, some pitfalls are hard to avoid. In general, forests store carbon and often benefit a region's ecology. But measuring the amount of carbon stored in a forest is extremely difficult, partly because more is usually sequestered underground than aboveground. In the early years after planting, forests generally store carbon quickly, but after 50 years or so, when the trees reach maturity, their growth rates slow.
An even more important consideration is that some forests are transient, so putting carbon in a forest may be like depositing money in a leaky bank. Forests may be cut for firewood, burned by lightning, or killed by insects a decade after planting.
Furthermore, some forestry projects have harmed indigenous people. According to SinksWatch, an initiative established to scrutinize carbon sequestration projects, the Face Foundation of the Netherlands has been planting carbon-offset trees in Mount Elgon National Park in east Uganda since 1994. Villagers living along the boundary of the park have been beaten and shot at and have had had their livestock confiscated by armed park rangers guarding the "carbon trees" inside the park. SinksWatch reports that forest-related projects in India often result in further loss of control over lands and resources by indigenous communities.
For the individual who wants to help the climate, it may be more useful to take direct personal action to reduce individual emissions rather than to buy offsets that may or may not cut emissions in some faraway place. Replacing appliances as they wear out with Energy Star units will have positive effects on CO2 emissions and on energy bills. Water heaters more than 10 years old can consume about twice the electricity as newer models. If an incandescent light bulb is used just a few hours a day, replacing it with a compact fluorescent bulb will pay for itself in less than 100 days. Drying just part of the laundry on racks indoors can save a great deal of energy. Replacing gas-guzzling autos with hybrids can save large amounts of gasoline. Perhaps the hardest CO2 generators to give up are airplane trips. The only way to save emissions here is simply to not take the trip.
Views expressed on this page are those of the author and not necessarily those of ACS.