Airlines from Virgin Blue to Quantas have been touting new eco-friendly programs in which passengers paralyzed by enviro-guilt over all those jet-fueled carbon dioxide emissions can pay an extra "carbon offset fee" for tickets. The money these passengers pay—sometimes as little as a dollar—is supposed to go to renewable energy or unspecified green causes and therefore make airline travel carbon neutral.

Carbon offset fees may be new, but the underlying notion goes back to the Middle Ages, when the Catholic Church sold wealthy people "indulgences" to offset the spiritual cost of their sins and assure a place for them in heaven. And yet at least the kids in 1380 knew that indulgences were bullshit. In Geoffrey Chaucer's classic medieval work The Canterbury Tales, written in the late 1300s, Chaucer makes fun of the thoroughly corrupt church "pardoner" character, a bombastic weirdo who constantly tries to sell everybody official-looking papers that pardon them for their sins. Chaucer was just one of many thinkers at the time who criticized the idea that any sin can be forgiven with a little gold. Polluting the environment isn't a sin in the Christian sense, and yet carbon-offset fees are clearly indulgences for a modern, scientific age. The idea that we can pay a little extra money on airline tickets to fix what carbon dioxide emissions are doing to the environment is as absurd as the notion that you can make up for your greedy ways by paying the church to forgive you.Not that money doesn't help eco causes. Obviously more money should be spent on inventing better forms of renewable energy, preserving endangered areas and reducing carbon emissions. But the problem is far more complicated than people want to believe. Our planet is in such sorry shape partly because humans are trying to better themselves. China is industrializing in order to make its citizens richer, but two weeks ago the Chinese National Population and Family Planning Commission published a report showing that environmental pollution from coal mining has caused the incidence of birth defects to jump 40 percent in the past six years.

There's no carbon-offset price you could pay to fix that. Nor is there an easy way to prevent such disasters from happening in the future if most of the world agrees that industrialization is the road to wealth. Do we use our carbon-indulgence money to fund Chinese populations' return to pre-industrial life, thus dooming that nation to a second-class economic status it doesn't deserve? Perhaps we could use our money to fund education that teaches Chinese kids about alternative energy. And then what kind of energy will they use in their classrooms while they're waiting for scientists to invent something that combusts cleanly and renewably forever?

Preservationist Marc Ancrenaz and his colleagues get it right in a recent article for PloS Biology, where they argue that preserving biodiversity must go hand in hand with eradicating poverty. "Most traditional conservation efforts were typically designed to exclude human residents," Ancrenaz's group writes. "This failure to consider the interests of local communities has resulted in a general lack of support for conservation and subsequent degradation of protected areas." In other words, if you don't help the people in a region, it doesn't matter how many carbon offsets you buy, the area will still suffer.Ancreanaz discusses two novel preservation programs that incorporate community development into their biodiversity agendas: the Kinabatangan Orang-utan Conservation Project in Borneo and the Tree Kangaroo Preservation Program in Papua, New Guinea. Both programs train and hire locals as researchers who can help preserve the habitats of orangutans and tree kangaroos respectively.

Programs like these are not panaceas. Improperly used, they are no better than carbon indulgences. But at least they aim to address the deep connection between human poverty and environmental suffering. Even better would be programs that help locals develop new sources of wealth, ones that don't require them to engage in logging or factory farming to earn money.

I'm not saying people should quit buying carbon offsets, because maybe some of that money will make it into the right hands. But they should recognize their actions for what they are: guilt-inspired payouts that assuage each individual's conscience, rather than a thoughtful remedy for problems that won't be solved with indulgences alone.

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