Is burning wood carbon zero? My in-law/relatives in Alaska say it can pollute quite a bit. Though I don't know how that relates to any carbon zero metric.
Burning wood is not carbon zero. It is the reverse of carbon sequestration in the sense that atmospheric CO2 was once converted to wood by the tree, and now the wood is being burned and the captured carbon release back into the atmosphere.
That could be nearly carbon zero (I don't know the contributions from soil and what mass remains as ashes, etc..), except when you consider the opportunity cost.
That burned tree, presumably healthy just prior, loses the ability to sequester any more carbon. A burned tree puts carbon in the atmosphere AND removes a carbon sequesterer simultaneously. That act is removing X amount of future sequestration until the tree would have naturally died and turned to soil. At that point most of that carbon would still be in solid form and not in the atmosphere.
I'm nitpicking at this point, but I lean toward burning wood as not carbon zero for the sake of opportunity cost.
It really only makes sense to measure the carbon capture at the level of the forest. When a tree is cut down or dies, it makes room for other trees to grow. Removing mature trees that are no longer growing very much can increase the rate of capture. Removing trees that are growing quickly and replacing them with smaller trees could reduce the rate of capture.
Either way, there is a limit to how much carbon a given forest will capture (rot releases it just as well as fire) and it will only do it for the life of the forest, which is usually not a geologic time scale.
Biochar is a potential solution, although the technology isn't there yet (at an industrial scale).
If wood is heated in an oxygen free environment it will turn into a form of charcoal. At the same time it will release gases (like methane) that can be captured and used as a fuel separately.
Rather than burning the charcoal, it is put back into the soil which effectively traps the CO2. This also improves the condition of the soil and reduces the need for fertilisers.
Only if the person actually plants a tree for every fire they burn. Even then, that does not offset the ash and other chemicals in the thick smoke ejected into the air that causes huge pollution problems at any scale.
I'm wondering how forest fires being a natural thing fit into your viewpoint. I don't think that fact entirely negates your point, but it does seem to dampen it at least.
Trees contain carbon. Burn trees, and they release carbon. New trees end up growing in the ash after it falls and re-capturing carbon. It's a natural, cyclic process.
The problem isn't that humans release carbon or other pollutants (burning trees, coal, oil, etc), it's the scale we do it at, and that we don't automatically re-capture it without doing extra work like planting more trees.
>Only if the person actually plants a tree for every fire they burn.
But wouldn't a tree be more likely to grow, and in the long run the expected number of trees in a forest be unaffected by the felling of any given tree? (the same can't necessarily be said for the felling of hundreds of trees of course).
Yes, like plutonium, but we're not going to be dumping that all over the place either.
Cyanide is also "natural" but not great for our health depending on the context. The same for the "chemicals" that, when burned, cause some nasty stuff compared to if it wasn't burned.
Long-term exposure to burning wood for heating and cooking can cause heart and lung disease.[1]
The main air pollutants in wood smoke are particulate matter (PM), carbon monoxide, carbon dioxide, nitrogen oxides and a range of other organic compounds like formaldehyde, benzene and polycyclic aromatic hydrocarbons.[1][2]
Using reverse-cycle refrigerant heating (or 'heat pumps') is probably the least worst polluting method of heating. Modern heat pumps can generate (well, move) four times more heat energy than used to drive the pump[3], with the added benefit of moving the source of pollution away from populated areas, or being carbon neutral via window, solar, hydro, geothermal.
Heat pumps only really work well when they have access to fairly warm temperatures. They are kind of worthless in the far north and direct fuel use is significantly more efficient.
If you burn coal for power at 40% efficiency and run a heat pump at 400% efficiency that's only 1.6x heat gain ignoring transportation losses. Drop that heat pump down to 150% efficiency and heating oil can become a better option.
In most areas using solar thermal heaters with backup resistance heating is actually the best overall option. But, in most of Alaska heating oil is much more viable.
