* Photo: Charles O'Rear/Corbis * Ronald Reagan's infamous claim that "trees cause more pollution than automobiles" contained a grain of truth. In warm weather, trees release volatile chemicals that act as catalysts for smog. But the Gipper didn't mention another point that's even more likely to make nature lovers blanch. When it comes to fighting climate change, it's more effective to treat forests like crops than like majestic monuments to nature.
Over its lifetime, a tree shifts from being a vacuum cleaner for atmospheric carbon to an emitter. A tree absorbs roughly 1,500 pounds of CO2 in its first 55 years. After that, its growth slows, and it takes in less carbon. Left untouched, it ultimately rots or burns and all that CO2 gets released.
Last year, the Canadian government commissioned a study to determine the quantity of carbon sequestered by the country's woodlands, which account for a tenth of global forests. It hoped to use the CO2-gathering power of 583 million acres of woods to offset its Kyoto Protocol-mandated responsibility to cut greenhouse gas emissions. No such luck. The report found that during many years, Canadian forests actually give up more carbon from decomposing wood than they lock down in new growth.
A well-managed tree farm acts like a factory for sucking CO2 out of the atmosphere, so the most climate-friendly policy is to continually cut down trees and plant new ones. Lots of them. A few simple steps: Clear the oldest trees and then take out dead trunks and branches to prevent fires; landfill the scrap. Plant seedlings and harvest them as soon as their powers of carbon sequestration begin to flag, and use the wood to produce only high-quality durable goods like furniture and houses. It won't make a glossy photo for the Sierra Club's annual report, but it will take huge amounts of carbon out of the atmosphere.
Related Inconvenient Truths: Get Ready to Rethink What it Means to Be Green 1: Live in Cities 2: A/C Is OK 3: Organics Are Not The Answer 4: Farm the Forests 5: China Is the Solution 6: Accept Genetic Engineering 7: Carbon Trading Doesn't Work 8: Embrace Nuclear Power 9: Used Cars — Not Hybrids 10: Prepare for the Worst
