Wood pellet boilers do so much more than cut your carbon emissions, but they are incredibly good at doing just that – while oil, gas and coal are fossil fuels produced deep within the earth’s crust over millions of years, wood pellet heat relies on trees, whose life cycle is much shorter and easier to harvest sustainably.
Both fossil fuels and trees contain “sequestered” carbon; in other words, carbon from the atmosphere or other sources is locked into the organic matter. Once that sequestered carbon has been released from fossil fuels, it takes much longer to sequester carbon from the atmosphere back into fossil fuels than it takes for trees to complete the same process.
Burning wood or wood pellets is considered carbon-neutral because it does not increase the amount of CO2 cycling through the atmosphere. Carbon is continually cycling through all living plants and animals – the natural growth and decomposition of wood is a short-term carbon cycle, whereas fossil fuels’ natural carbon cycle is significantly longer – by millions of years.
Growing trees converts atmospheric CO2 to biomass, and naturally decomposing (or burning) trees release CO2 back into the atmosphere, replacing what was just removed.
This carbon cycle remains in balance when there is no net increase of carbon in the atmosphere – in other words, by replacing the trees that are used for fuel, paper, and other products wherein the wood is ultimately decomposed. Maine’s forestry economy focuses heavily on this balance, working to sustain the production of biomass to support its use.
However, when fossil fuels are burned, there is a net increase of CO2 because most of it represents a surplus of atmospheric carbon not needed for the biomass carbon cycle. Because fossil fuels are currently used in the production of biomass such as wood pellets, there is a small net increase in atmospheric carbon – we adjust for a 10% net increase, which accounts for the 90% decrease in carbon emissions. However, as biofuel become more and more popular, we may see a decrease in the net carbon increase for wood pellets.