Green Heat: Clearing the air about wood heatingAugust 2018
Does heating with wood cause global warming ?
What about local air quality ?
Does wood heating harm the forest ?
Is wood heating safe?
Good questions. Real Answers.
Wood heating and global warming
By heating with wood you do not contribute to the greenhouse effect as
you would by heating with one of the fossil fuels like oil and gas. When oil
and gas are burned, carbon that has been buried within the earth for
thousands of years is released in the form of carbon dioxide, a by-product
of combustion. The result is an increase in the atmospheric concentration of
carbon dioxide, the cause of the greenhouse effect.
Although carbon makes up about half the weight of firewood and is
released as carbon dioxide when the wood is burned, it is part of a natural
cycle. A tree absorbs carbon dioxide from the air as it grows and uses this
carbon to build its structure. When the tree falls and decays in the forest,
or is processed into firewood and burned, the carbon is released again to
the atmosphere. This cycle can be repeated forever without increasing
atmospheric carbon. Heating with wood, therefore, does not contribute to
the greenhouse effect. And there’s more good news: when the use of
wood for energy displaces the use of fossil fuels, the result is a net
reduction in greenhouse gas emissions.
Wood heating and air quality
Wood is not an inherently dirty fuel that causes serious air pollution. While
it is true that old technology like open fireplaces and simple heaters could
not burn the wood completely, the new generation of woodburning
appliances produce almost no visible smoke and deliver efficiencies in the
range of 70 percent. Developed since 1980, improved technology has cut
particulate emissions (smoke) by about 90 percent compared with
conventional equipment. Wood may not be the best fuel choice in densly
populated urban areas where automobile exhaust and other pollution
already puts excessive strains on the air shed. But in suburban, small town,
and rural areas, wood makes good sense.
Wood contains only a negligable amount of sulphur, an element that leads
to acid rain. In this age of environmental awareness, a big advantage of
wood over the fossil fuels is that its main environmental impact occurs at
the point of use and is visible for all to see. In contrast, the real
environmental impacts of oil and gas are hidden from view because they
occur during extraction, refining and transportation of the fuels to market.