The Greenhouse Effect
Wood is a renewable resource that, when used for heating, does not contribute to the greenhouse effect.
The greenhouse effect is the process by which heat from the sun, reflected off the Earth, is absorbed by carbon dioxide and water vapor in the earth's atmosphere and then reflected back to the Earth's surface. A normal level of carbon dioxide in the atmosphere is necessary to keep the earth's surface at a proper temperature.
However, as human activity increases, the level of carbon dioxide in the atmosphere may increase. It is belived that an escalation of the greenhouse effect due to human activity causes global warming - an increase in average global temperatures.
Burning fossil fuels, such as coal, oil and gas, releases carbon that otherwise would have remained undisturbed beneath the earth's surface.
Wood: A Clean, Renewable Fuel
Burning wood releases carbon dioxide, but causes no net increase in atmospheric carbon dioxide because of the natural carbon cycle. Trees acquire the carbon they need for growth by absorbing carbon dioxide from the atmosphere. When trees die and decompose on the forest floor, or are burned by naturally occurring forest fires, the carbon stored within them is released as carbon dioxide into the atmosphere. Then other growing trees absorb the carbon dioxide from the atmosphere. This process can repeat forever without causing a net increase in atmospheric carbon dioxide levels. The same is true for heating with wood.
Using sustainable forestry practices, wood can be harvested as a completely renewable resource and burned without causing a net increase in carbon dioxide or contributing to global warming. Burning wood in place of fossil fuels can decrease the amount of carbon dioxide released into the atmosphere. Since an outdoor wood furnace can meet 100% of the owner's heating requirements, it can replace the use of traditional fuels for heating homes, domestic hot water, garages, barns, greenhouses, swimming pools, and other applications.
Decreases Landfill Waste
Burning waste wood and reclaiming heat energy also benefits the environment. Outdoor wood furnaces work very well with waste wood because of the large firebox and thermostatic control. When disposed of in landfills, wood waste decomposes producing methane, another greenhouse gas.
However, outdoor wood furnace owners should burn only wood in their furnaces. An outdoor wood furnaces should not be used for burning garbage like plastics or rubber. Burning these materials can release toxic chemicals and offensive odors into the air. Combustion gases created from burning plastic and rubber can also form acid in the firebox, causing a high rate of corrosion and decreasing the life of the furnace.
Improves Forest Health
Much of the wood harvested for outdoor wood furnaces comes from trees downed by storms and trees with limited life spans. Harvesting these trees allows for new forest growth and may reduce the risk of forest fire.
No Hidden Environmental Impacts
With traditional heating fuels, such as coal and oil, most people only see emissions at the point of use. Few people ever see the complete cycle of how the fuel is extracted, processed, transported, and distributed. For example, oil must be extracted at an oil rig and processed at a refinery. It is then shipped thousands of miles by oil tanker and by truck or delivered by pipelines, which are powered by electricity. Coal goes through a similar cycle of mining, transportation, and handling before combustion. Consumers rarely see the full environmental impact and energy consumed during these processes. Wood is most often cut locally, near the point of use, and does not need to be transported great distances. Wood requires much less energy input during harvest and distribution processes than fossil fuels.
Using wood as a heating fuel is endorsed by the U.S. Forestry Service and the Union of Concerned Scientists.