There have been a lot of concerns expressed about greenhouses gases produced by processes such as brewing, livestock production and timber harvest. As an ecologist, I see a difference between what I call cycled greenhouse gases and non-cycled gases.
Consider a stand of grass: it greens up and starts growing in the spring, capturing carbon dioxide and using it to produce hydrocarbon compounds that make up its cellular structure. This growth dies in the winter and over the next few months or years decay releases its captured carbon dioxide back into the atmosphere. Or some of this grass may be eaten by an animal herbivore, who digests it and converts it into body energy and structure, releasing and exhaling carbon dioxide in the process. Next year the cycle repeats -- part of the cycle that has gone on for eons with no net increase in greenhouse gases. This is even true if the grass produces fodder for livestock or grains for breweries. This natural plant product is going to be consumed, whether by decay, livestock, brewers or in your breakfast, without producing a systemic net increase in greenhouse gases nor providing any means for reducing greenhouse gas production. The total carbon dioxide produced in a brewery is no more than the total carbon dioxide produced by a bunch of barley-eating goats or a host of barley-bread eating humans consuming the same tonnage. (Yes, some of it does get converted to methane, a powerful greenhouse gas, but we have ways for converting that back to carbon dioxide and water through combustion - have you ever lit your flatulence?) Of course some ecosystems can retain vegetative hydrocarbons for long periods, e.g., peat bogs and old growth forests. But none of it approaches the storage length of hydrocarbons in fossil fuels, which in effect are megamillennial old sources of non-cycled greenhouse gases. Does this make sense? Doesn't it seem prudent to concentrate on reducing fossil fuels combustion rather than get distracted by cycled sources of greenhouse gases? Warren W. Aney Senior Wildlife Ecologist Tigard, OR 97223 (503) 539-1009 (503) 246-2605 fax
