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Not a bad write-up, but there's no way forests can significantly sequester fossil carbon from oil, gas and coal combustion at any meaningful rate. Mature forest

Not a bad write-up, but there's no way forests can significantly sequester fossil carbon from oil, gas and coal combustion at any meaningful rate. Mature forest is mostly in steady-state with respect to total carbon storage, as dead trees decay to atmospheric CO2 at the same rate that growing trees absorb atmospheric CO2: https://academic.oup.com/forestry/article/90/1/125/2605858 https://academic.oup.com/forestry/article/90/1/125/2605858 Limited harvesting of trees for conversion to long-lived products has some additional effect, but eventually even wood-framed homes get attacked by termites etc, so estimates are that well-designed wood homes have a 100-150 year lifetime. If you dump logs in the anoxic waters of the Black Sea, however, they can last 1000s of years (see old shipwrecks). The only realistic way to stabilize the atmospheric CO2 level is to steadily eliminate fossil fuels from the energy mix, bringing various renewable energy sources online at the same rate. Yes, that's an expensive, technologically challenging proposition, but so was building the global fossil fuel infrastructure in the first place. So-called 'carbon markets' in contrast have been entirely ineffective in slowing the rate of atmospheric CO2 growth, it's just a game of deck chairs on the Titanic, with some bonuses for biodiversity conservation. Fundamentally, you can run a modern industrial civilization on renewables - iron and steel, fertilizers and materials, even jet fuel can be produced using carbon and hydrogen sourced from air and water, and with power from sunlight and wind. It's going to take a whole lot of wind turbines and solar panels, however, as well as many new factories. It'll require diversion of a significant fraction of all industrial activity to the task on a global scale.

nkurz 4y ago
I'd go farther: I thought it was a surprisingly good writeup for a general audience magazine! Northern Woodlands is interesting, partly because they take a somewhat pro-logging stance for what is essentially an environmentalist nature-oriented publication. We'll see where the next parts of the series go. Your points about the limitations of forests for carbon sequestration are a good reality check, but there are others that are more optimistic that improved forest management can be play at least a regionally significant role. Here's a recent Harvard Forest publication claiming that forests currently offset about 14% of New England's 2020 fossil fuel emissions, a number which could be increased to 21% with better practices: https://harvardforest1.fas.harvard.edu/sites/harvardforest.fas.harvard.edu/files/publications/pdfs/Meyer_NEClimateImperative_2022.pdf https://harvardforest1.fas.harvard.edu/sites/harvardforest.f...
credit_guy 4y ago
> there's no way forests can significantly sequester fossil carbon from oil, gas and coal combustion at any meaningful rate Not true. In the US, forests remove about 10% of the greenhouse emissions. Can we get more? I think we can, without implausible efforts, increase this to 15% (see note). But even if we can't, this 10% is still very important. Why? Because it means we need to reduce our emissions by only 90% to achieve net zero, not by 100%. This might seem insignificant, but it isn't. People like to point out to parts of the economy that appear nearly impossible to de-carbonize, and then throw up their hands and claim that we'll never achieve net zero. An example is airplane emissions. But a much more important example is the intermittency issue of solar and wind. Batteries alone can't solve this, not if they don't become 100 times cheaper, and this will not happen in the next 3 decades. But natural gas peaker plants can solve this. Fun fact: right now the total carbon sequestration provided by the forests is almost precisely equal to the total greenhouse emissions of the natural gas power plants. If you keep these plants, or just a small fraction of them, and use them only to smooth out the electricity output of solar and wind, then the forests will sequester many times more than the peaker plants will emit. So, all those who say solar and wind can't take us to net zero are wrong. (Note about potential additional forests sequestration: there are about 600 million acres of forest in the US. There are about 30 million acres planted with corn that is used to produce "bio"-ethanol. If we discontinue that subsidy, and plant the 30 million acres with forests, a simple rule of 3 would indicate that we'll increase sequestration by 5%. However young forests sequester much more carbon, and release much less, that it's quite likely the additional sequestration could be 50% for a few decades. Not forever, but we can buy 3 decades of sequestration, and that's what we need).
TinkersW 4y ago
Well a good start would be to cease logging of all redwoods, they take over a thousand years to reach steady state, and will continue sucking down carbon over that time(and the the larger the redwood the faster its absolute volume increases, so logging is idiotic). CA still has most of its redwood forests being actively logged, so much for faux environmentalism in liberal CA.

nkurz 4y ago

I'd go farther: I thought it was a surprisingly good writeup for a general audience magazine! Northern Woodlands is interesting, partly because they take a somewhat pro-logging stance for what is essentially an environmentalist nature-oriented publication. We'll see where the next parts of the series go. Your points about the limitations of forests for carbon sequestration are a good reality check, but there are others that are more optimistic that improved forest management can be play at least a regionally significant role. Here's a recent Harvard Forest publication claiming that forests currently offset about 14% of New England's 2020 fossil fuel emissions, a number which could be increased to 21% with better practices: https://harvardforest1.fas.harvard.edu/sites/harvardforest.fas.harvard.edu/files/publications/pdfs/Meyer_NEClimateImperative_2022.pdf https://harvardforest1.fas.harvard.edu/sites/harvardforest.f...

credit_guy 4y ago

> there's no way forests can significantly sequester fossil carbon from oil, gas and coal combustion at any meaningful rate Not true. In the US, forests remove about 10% of the greenhouse emissions. Can we get more? I think we can, without implausible efforts, increase this to 15% (see note). But even if we can't, this 10% is still very important. Why? Because it means we need to reduce our emissions by only 90% to achieve net zero, not by 100%. This might seem insignificant, but it isn't. People like to point out to parts of the economy that appear nearly impossible to de-carbonize, and then throw up their hands and claim that we'll never achieve net zero. An example is airplane emissions. But a much more important example is the intermittency issue of solar and wind. Batteries alone can't solve this, not if they don't become 100 times cheaper, and this will not happen in the next 3 decades. But natural gas peaker plants can solve this. Fun fact: right now the total carbon sequestration provided by the forests is almost precisely equal to the total greenhouse emissions of the natural gas power plants. If you keep these plants, or just a small fraction of them, and use them only to smooth out the electricity output of solar and wind, then the forests will sequester many times more than the peaker plants will emit. So, all those who say solar and wind can't take us to net zero are wrong. (Note about potential additional forests sequestration: there are about 600 million acres of forest in the US. There are about 30 million acres planted with corn that is used to produce "bio"-ethanol. If we discontinue that subsidy, and plant the 30 million acres with forests, a simple rule of 3 would indicate that we'll increase sequestration by 5%. However young forests sequester much more carbon, and release much less, that it's quite likely the additional sequestration could be 50% for a few decades. Not forever, but we can buy 3 decades of sequestration, and that's what we need).

TinkersW 4y ago

Well a good start would be to cease logging of all redwoods, they take over a thousand years to reach steady state, and will continue sucking down carbon over that time(and the the larger the redwood the faster its absolute volume increases, so logging is idiotic). CA still has most of its redwood forests being actively logged, so much for faux environmentalism in liberal CA.