Why is burning wood considered “carbon neutral” while burning coal is considered not carbon neutral?

Answer 1

Burning wood gives off - When wood is burned, the combustion reaction produces heat and emissions in the form of water, organic vapors, gases, and particulates. The emissions of most concern are carbon monoxide (CO), carbon dioxide (CO2), sulfur oxides (SOx), and nitrogen oxides (NOx), particulates, various toxins could be present depending upon whether the wood is treated or not.

Burning coal gives off - Sulfur dioxide (SO2), Nitrogen oxides (NOx), Particulates, Carbon dioxide (CO2),

Mercury and other heavy metals, which have been linked to both neurological and developmental damage in humans and other animals

Upon close inspection, both appear to give off similar emissions. Both give off CO2 along with other particulates and gases.

There are several factors to consider, including:

Source of Carbon.

Carbon (CO2) in wood – Short Carbon Cycle - comes from the local environment. It is taken up during a tree’s lifetime and released back into the environment (Air, Water, Soil) when it dies and is consumed (decomposes, is eaten, burned, etc.) So basically a tree gives off nearly the same amount of carbon (per pound) as it absorbs in its life time. Hence “net zero.” 

Carbon (CO2) in coal and other fossil fuels – Long Carbon Cycle – has been sequestered away from the active carbon cycle and environment (in which we all live) for between 16,000 and 500 million years or more (much longer than any of us have been around, and insufficient quantities to allow for a reduction in Earth’s temperatures and stabilization of the atmosphere at nominal conditions to support animal life.

Before the industrial age and the introduction of mass burning of fossil fuels, the atmosphere remained relatively stable. Yes, there are momentary oscillations due to natural events. However, the average was stable.

Once we began burning fossil fuels, we also began to release lots of carbon that had been sequestered away from the atmosphere, for between tens of thousands up to hundreds of millions of years. Thus, the increase of CO2 in the atmosphere and in oceans.

So, when we say that burning wood is carbon neutral, it is because when wood burns, it only emits roughly the same amount of CO2 back into the environment that it absorbed during its lifetime, during a short cycle. While burning coal introduces long sequestered concentrated CO2 into the short carbon cycle.

But this is only part of a much larger global problem. 

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Wyzant. 

Ron P.