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I suspect many of the folks who'd be interested in this kind of thing (lowtechmagazine) are the same ones very concerned about climate change and pollution. May

I suspect many of the folks who'd be interested in this kind of thing (lowtechmagazine) are the same ones very concerned about climate change and pollution. Maybe I missed it by just skimming, but is there any discussion in there of the particulates and CO2 output of burning wood? In a very real sense burning wood is the same thing as burning coal, minus millions of years of pressure. Perhaps for their next article on low-tech stoves they can investigate the higher energy density and improved generation capabilities of coal. Why, in some places you can even find convenient coal chutes!

tom_mellior 6y ago
> In a very real sense burning wood is the same thing as burning coal, minus millions of years of pressure. Burning wood only emits CO2 that was in the atmosphere recently. Regrowing an equal size tree in the same place captures that CO2 again. This means net zero CO2 emissions (in theory). In comparison, you would need to plant new trees in new places (and not cut them down) to offset the CO2 from fossil coal.
- acidburnNSA 6y ago
  Biofuel is almost as bad as coal from a carbon emission point of view. Lifecycle emissions are about 740 gCO₂-eq/kWh, c.f. 840 for coal (Source: Schlomer 2014 IPCC meta-analysis). The problem is that you can burn a log that took 20 years to accumulate carbon in 1 hour. Sure it renews, eventually. But if lots of people do this the concentration of carbon in the atmosphere would equilibriate at a level inconsistent with solving climate change. And the particulate air pollution from wood is a true killer. This concept is deeply flawed because of carbon emissions and air pollution.
  - tom_mellior 6y ago
    Agreed with all your points, I wouldn't want us to return to more burning of wood. I was just pointing out the categorical difference to burning fossil fuels, which even theoretically aren't part of the same life cycle and cannot be offset in the same way -- we can't grow back forests from millions of years ago.
    - acidburnNSA 6y ago
      Can't argue with that! Certainly wood would last longer as a resource in the long term. A book on energy once classified energy as new (biofuel, solar, wind, hydro), old (fossil fuel) and really old (nuclear, geothermal, tidal). I kind of like that. Of course all of the above are derived from nuclear fusion in stars if you track it back far enough.
    - 7952 6y ago
      But they can be offset in the same way. You just plant trees. I don't see what difference it makes if the biomass is six months old or millions of years. What matters is the total amount of CO2 in the atmosphere. I just don't think the idea of a "life cycle" is meaningful here. It is similar to labelling something as "natural".
      - tom_mellior 6y ago
        > I don't see what difference it makes if the biomass is six months old or millions of years. The coal in the ground isn't a snapshot of a single point in time in the past. It represents a succession of trees. Some were buried in the ground, and others grew above them. More were buried, and more grew above. Many layers were deposited over millions of years. The totality of coal below ground represents a lot more trees than could ever grow at once on the surface. Burning fossil coal puts CO2 into the atmosphere that cannot be offset in any meaningful way by planting trees. Not on a time horizon shorter than millions or at least thousands of years. We would have to grow trees, then cut them down, and sequester them below ground again in a way that keeps the carbon from escaping. Almost like, you know... coal.
        7952 6y ago
        The difference then is that fossil fuel + tree planting increases the total amount of carbon above ground. But in the short term there isn't a difference in the amount of CO2 in the atmosphere. Fossil fuel + tree planting is not a long term solution, but neither is wood burning. And I don't think wood burning should get a free pass just because somewhere a tree is growing. Ideally a carbon tax would apply.

tom_mellior 6y ago

> In a very real sense burning wood is the same thing as burning coal, minus millions of years of pressure. Burning wood only emits CO2 that was in the atmosphere recently. Regrowing an equal size tree in the same place captures that CO2 again. This means net zero CO2 emissions (in theory). In comparison, you would need to plant new trees in new places (and not cut them down) to offset the CO2 from fossil coal.

acidburnNSA 6y ago
Biofuel is almost as bad as coal from a carbon emission point of view. Lifecycle emissions are about 740 gCO₂-eq/kWh, c.f. 840 for coal (Source: Schlomer 2014 IPCC meta-analysis). The problem is that you can burn a log that took 20 years to accumulate carbon in 1 hour. Sure it renews, eventually. But if lots of people do this the concentration of carbon in the atmosphere would equilibriate at a level inconsistent with solving climate change. And the particulate air pollution from wood is a true killer. This concept is deeply flawed because of carbon emissions and air pollution.
- tom_mellior 6y ago
  Agreed with all your points, I wouldn't want us to return to more burning of wood. I was just pointing out the categorical difference to burning fossil fuels, which even theoretically aren't part of the same life cycle and cannot be offset in the same way -- we can't grow back forests from millions of years ago.
  - acidburnNSA 6y ago
    Can't argue with that! Certainly wood would last longer as a resource in the long term. A book on energy once classified energy as new (biofuel, solar, wind, hydro), old (fossil fuel) and really old (nuclear, geothermal, tidal). I kind of like that. Of course all of the above are derived from nuclear fusion in stars if you track it back far enough.
  - 7952 6y ago
    But they can be offset in the same way. You just plant trees. I don't see what difference it makes if the biomass is six months old or millions of years. What matters is the total amount of CO2 in the atmosphere. I just don't think the idea of a "life cycle" is meaningful here. It is similar to labelling something as "natural".
    - tom_mellior 6y ago
      > I don't see what difference it makes if the biomass is six months old or millions of years. The coal in the ground isn't a snapshot of a single point in time in the past. It represents a succession of trees. Some were buried in the ground, and others grew above them. More were buried, and more grew above. Many layers were deposited over millions of years. The totality of coal below ground represents a lot more trees than could ever grow at once on the surface. Burning fossil coal puts CO2 into the atmosphere that cannot be offset in any meaningful way by planting trees. Not on a time horizon shorter than millions or at least thousands of years. We would have to grow trees, then cut them down, and sequester them below ground again in a way that keeps the carbon from escaping. Almost like, you know... coal.
      - 7952 6y ago
        The difference then is that fossil fuel + tree planting increases the total amount of carbon above ground. But in the short term there isn't a difference in the amount of CO2 in the atmosphere. Fossil fuel + tree planting is not a long term solution, but neither is wood burning. And I don't think wood burning should get a free pass just because somewhere a tree is growing. Ideally a carbon tax would apply.