When the emissions tied to land use conversions were factored in, the difference was phenomenal. Instead of ethanol being an answer--a silver bullet to replace fossil fuels--ethanol would worsen the carbon emission situation for anywhere from 30 to 350 years, depending on the details of the land use conversion.
These scientists and economists factored in carbon emissions tied to deforestation and changes in soil condition, both on the conversion site and a replacement site. Additionally, "foregone sequestration:" the amount of forests, soils, grasslands, peatlands, etc, taken out of their important carbon storage function, were also recognized and factored in.
Although the Science articles focused on "agrofuels," the implications for forest conversions to fuels for energy, whether biomass-to-electricity, biomass-to-heat, or wood-to-ethanol are obvious: we ignore land use conversions to our peril; and perhaps there is something better to do with wood than burn it for energy.
Today, one-fifth of all carbon emissions are the results of deforestation, or the loss of carbon sinks which store, rather than emit, carbon dioxide. Additionally, when wood is burned, carbon dioxide is released, so this adds to the loss. But when wood is used as wood (for homes, furniture, or trees) carbon continues to be stored. Forest fires will release carbon too, but only when they occur. Newly bared soil from clearcuts or excessive selection also releases carbon.
How to keep the balance? A few policy and practice ideas may help. Keep trees growing to their maximum carbon storage potential. Focus on thinning and spacing to reduce fire hazards, but maintain shade and soil quality, and try to recreate old growth forest conditions. Avoid fossil fuel additives such as fertilizers and pesticides. Utilize tree thinning for wood products, and not for burning. Create new markets for small diameter wood. Make sure only true "waste" is being burned for energy, and not "hog fuel" made from chipped-up trees.
Subsidize labor-intensive fire hazard reduction techniques that reduce fuel loads while maintaining truly diverse forest conditions, rather than plantation style monocultures. By creating both jobs and small diameter materials, new craft industries can begin to emerge.
The Center for Environmental Economic Development has begun a Forests and Energy project to bring the climate change discussion home to our bioregion, and to question through productive and polite discourse some of the assumptions now driving the forest industry.
Twenty percent greenhouse gas emissions through forest loss? This is a statistic, and a condition, that must be turned around....
Please get in touch, at cecilr@humboldt1.com
1 Science, Feb. 29, 2008, Vol. 319, (1235-1240).
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TOC for Forest & River News, Spring 2008