Mature forests are at best net carbon neutral, and at worst net carbon emitters. Comparing our current emissions with amount sequestered per hectare of forest immediately gives that we don’t have nearly enough suitable unused land to plant new forests to make up for our current emissions. The only viable way to use forests to sequester carbon is to cut down immense numbers of trees and bury them underground. I don’t see anyone going to seriously propose this.
Wouldn't a better solution be to encourage more things built of wood? Cut the trees down and use them, while replacing with more.
E.g. Encourage more wooden houses and your not only capturing carbon but storing it separately so more can be captured in that same place.
While there are probably many better solutions, you would think whatever they are we need something that can continue to capture carbon ongoing. A forest, as great as they are for a plethora of reasons, is fairly finite in terms of carbon capture.
Wood isn't an effective means of sequestration unless you also bury it.
And it isn't going to fix things in terms of sheer volume either. We've cut down forests and burnt fossil fuels. Replenishing forests only reversed the effects of the former and doesn't account for the carbon released via the latter.
planting trees isn't a realistic carbon sequestration. it just delays when the carbon is released (dead decaying tree). The only proper carbon sequestration is to capture it and stick it back in the ground from where it came. there's obvious challenges with that.
The problem we are trying to solve is keeping the co2 stored somewhere. In the past there were no wood eating fungi which meant forests were really good at co2 sequestration. That is no longer true, plants alone cannot get rid of excess CO2 anymore so we need humans to do something.
When we say "plant based sequestration" we are (I for one am) not talking forests. Carbon sequestration in forests is wilfully ignoring the economic and practical drawbacks:
Forests only sequester carbon as they grow. After that they are carbon neutral. You end up with land that cannot be used for any economic purpose. (The creatures and plants that live in it have a value too, but that is not part of this argument).
After that, at some point, in a year, ten years, a hundred years, the forest burns. And all the carbon is released.
A pointless waste of time. We do it because we are obsessed with things we can count (one tree, two trees....) and fixated on the short term.
Increase depth of top soil all over our agricultural land. It increases productivity and sequesters carbon. But it has no profit centre and is hard to measure, and given our "big man" capitalist culture that is the problem.
We really must stop producing CO2. That is the only answer that does not steal the future from our children
Once the forest is mature, though, it's mostly just storing the carbon, rather than acting as an effective sink. So maybe you need to cut some trees down from time to time, and store that wood somehow where the carbon will be locked up for a long time without taking up valuable land area.
The problem is that we keep pulling carbon out of the ground and introducing it into the ecosystem. If we don't have a corresponding method of removing it from the ecosystem, we'll eventually run out of room for forests that we can use to store it. Some of that happens by natural means, but we'd have a bit more breathing room if we could figure out how to make it happen faster.
It takes about a decade for a new tree to start capturing much carbon, and then you have to maintain a forest for 100 years and prevent it from burning, etc. Seems like something we should do more of, but surely not a complete solution to the problem.
This is certainly true, but we are talking about absolutely staggering amounts of land. As it stands now, ~30% of our planet's landmasses are covered in forest. Also, some kinds of forest are much better at sequestering carbon - specifically, the tropical rainforests that are being cut and burnt in the tropics.
Re-forestation is part of the solution, but it's no panacea.
I think the problem is that forests cycle a lot of carbon, absorbing and then releasing a lot throughout the year. If the size of that reservoir goes down (implied by the article), then there is more 'free' carbon to go elsewhere in the system.
The only problem is that we don't have nearly enough space for that.
An acre of trees stores ~393 tonnes of carbon dioxide permanently (in Vermont anyway, other areas probably vary a lot) [1]
Humans generate ~40 Gtonnes of CO2 a year. That means we need to be adding ~100 million acres of trees every year to capture that. There's currently 4 billion hectares of forest cover - that's around 10 billion acres.
If we replanted every area which has seen deforestation since 1990 we'd get another 400 million acres, or 4 years of emissions. After that, we're fighting an uphill battle. Forests currently cover 31% of the earth. 29% of that surface is desert, 3% is urban areas and 10% is covered in ice. To keep on top of emissions we'd need to add 0.3% of the total each year globally, or 1.2% of the land which could actually grow trees.
That might be doable in 5 years, but 10 years? 15 years? 30 years?
Re-forestation may be part of the solution, but it can't be the only part.
How much of your valuable land would you like to convert to forest? Unless we start paying people more to keep forests than they otherwise could in real estate, agriculture, etc it is a nice argument that trees can sequester carbon but unrealistic that it can happen on a scale large enough to move the needle.
A lot of assertions there. You lost me at “Forestry changes aren't nearly enough to offset anthropogenic emissions from other sectors”. Can you explain your math there? Is there a limit to how much carbon we can warehouse in trees (living and milled)?
The bigger problem is that a lot of carbon offset measures involve planting trees/forests. But forests burn (and will do so with greater frequency as the temperature increases).
Solving that would require complex carbon cap & trade regulations to be enforced.
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