A new trend is to become a zero-sum contributor of greenhouse gases ("carbon neutral"). Some people avoid the lifestyle change, however, and instead purchase "offsets." But do such buy-offs really make a difference? Yes and no.
The idea behind carbon offsets is simple: Make a contribution to any project that reduces greenhouse gases, such as a tree-planting scheme or a business that captures methane from landfills, and thus compensate for one's personal additions to global warming.
Spend enough money and your conscience seems clear as regards being responsible for climate change.
The World Bank estimates that the global market in voluntary offsets, by both businesses and individuals, grew to about $100 million in 2006, and will rise again this year. Last month, for instance, the US Forest Service announced a Carbon Capture Fund that will sell offsets to individuals. Since trees absorb CO2, the fund will underwrite tree-planting in Idaho, Montana, and South Dakota. Buyers will first use a "carbon calculator" to measure how much their activities at home, on transportation, at leisure, or on the job produce greenhouse gases, and then pay a certain amount to have seedlings planted in treeless areas. A small family, for instance, might pay under $200 per year, depending on its lifestyle.
Another attempt to sell offsets is General Electric's "Earth Rewards" credit card. Up to 1 percent of each purchase with the card is used to fund programs that claim to reduce greenhouse gases.
Using offsets has been criticized as an easy way to relieve "carbon guilt" without making changes in one's daily use of fossil fuels that would reduce emissions directly. Offsets are likened to indulgences the Roman Catholic church once gave to those who paid to rebuild St. Peter's Basilica in 1517 – buy a pardon for sins. (The campaign's slogan: "As soon as the coin in the coffer rings, the soul from purgatory springs.") The practice was criticized by Martin Luther, helping to ignite the Protestant Reformation.
Carbon offsetters, however, face a different challenge. Can they be sure a project really reduces emissions? Will that reforestation really happen or, even if it does, was it going to happen anyway? How can one check on a new, supposedly more efficient power plant in, say, China? Will the CO2 savings be measured accurately?
Global rules on offsets don't exist, although the Climate Group, a coalition of businesses and local governments, plans to set voluntary standards soon.
No doubt charlatans need to be shaken out of many offset programs. But that shouldn't stop those who want to help from doing so. As always, it's buyer beware: Investigate before you buy, and follow up. And keep offsets local, if possible.
Carbon offsets should remain the last leg on a three-legged stool for supporting efforts against global warming. First comes personal conservation, then pushing industry and government to change policies. After that, one can indulge in soothing carbon guilt by shopping carefully for offsets. And why stop at breaking even? Some may want to go beyond carbon neutrality.
Bear in mind that doing one's bit for global warming can't simply be bought like a license to keep doing business as usual. Personal sacrifice in energy use is still the best path to saving the planet.