Great post. We’re suffering the double failure here of past deforestation and single species replanting. Any disease, unusual weather or pests like pine beetle have extreme effects which can be minimized by planting pioneers. Sadly not a short term climate solution.
Thanks David! Yes, single species monocultures are an extremely fragile option in a changing climate. Disease/pest outbreaks are already proving to be a major problem for such systems, and they are only going to get worse. There's a real tradeoff to be had here with regard to short-term/near-term benefits, which come with long-term costs vs. less effective near-term benefits, but greater long-term benefits. I think a compromise can be met with careful planning.
Johan Rockström, in the interview below, mentions that a big part of the carbon that that trees capture is actually a stress response, and therefore we should not rely on forests. In fact, he says, some forests already have become a source of carbon instead of being sinks, although we do not know yet exactly the reason. But a healthy planet in equilibrium, he says, takes up as much carbon dioxide in the the photosynthesis as it releases through respiration.
Thanks Lazaros! Yes, interesting point. I think the key point is that we don't know how much buffering capacity forests have. How much more can they take? The net emitters are emitting because of a combination of things, including unsustainable forestry practices, fire regimes that are enabled due to forest modification etc. So it's not that healthy, natural functioning forests are net emitters necessarily, it's that they become net emitters when they have been modified in some way or another. However, if climate change continues to increase fire regimes and disease outbreaks like bark beetle in Canadian forests etc., then we don't know the thresholds of when forests (even unmodified forests) shift from being sinks to sources of carbon. Either way, forests are just part of the toolbox for the carbon problem, given there is so so much more carbon in the atmosphere than there was historically due to fossil fuel use. Cheers!
Great post Jono, I think it's really important that we distinguish between mitigating carbon in the atmosphere that came from land use change and that from fossil carbon. As is referenced in the article below "While the carbon atom in the tree is the same as the carbon atom from burned fossil fuels, that’s where the similarity ends. The fossil carbon the tree is purportedly mitigating is a separate and additional source." So notwithstanding the points you made, its crucial to understand that planting a tree does not mitigate a gram of fossil carbon only the carbon emitted when the tree that was there before was chopped down. https://theconversation.com/were-burning-too-much-fossil-fuel-to-fix-by-planting-trees-making-net-zero-emissions-impossible-with-offsets-217437
Thanks Mike! Very good point. Thanks for sharing. I particularly like your ending: "Deforestation has to be reversed, and more trees must be planted to sequester the carbon emitted through past land-use changes. But planting trees instead of stopping fossil emissions is not the answer. Planting trees as well as not emitting fossil carbon is the only solution."
Jonathan, we are on the same page. Sweden converted huge areas of bog and wetlands to forest (not for "climate" reasons but for production reasons) the last hundred years, and in most cases that has lead to decreased carbon storage.
I don't have a single preferred option to be honest. Disclaimer, I'm not an expert on this. But it's context dependent, really depending on the economic situation of the particular location. Many such things come down to $$. So having the right economic incentives is key. Whether bottom-up or top-down is more effective again depends on the situation. etc. Perhaps I should get an expert in to post on such a topic?
It's the question that always comes to mind for me at least, reading posts like this one. We can design all the perfect tools for restoration. But we still have to figure out how to reward people for stewarding forests more than we reward, say, cattle ranching.
Good article. Jonathan covers a lot of the issues surrounding reforestation. It's NOT just a matter of sticking seedlings in the ground.
However, reforestation is the ONLY proven method that exits for actually pulling CO2 out of the atmosphere"at scale". Everything else, is basically impossible with any realistic technology we can develop and deploy at scale in the next 50 years.
Reforestation can work. But there's a BIG price.
040 - What if I told you there was a way to pull enough CO2 out of the atmosphere to cool the planet down over the next century. How many lives would you be willing to sacrifice to save the FUTURE? - On Reforestation.
Another great piece! I have a question about the section where you mention that “monocultures of fast-growing species like pines tend to get cut down after a relatively short time period (or begin to die off) and so do not end up being long-term carbon sequestration solutions.” Is there a timeline for how long it takes for a single reforestation attempt to become net positive in terms of carbon sequestration? Do we get benefits immediately after the trees have been planted, or does it take a while to take effect? Thanks for your insight and expertise!
Thanks very much, Carrie! Good question. There are a bunch of factors that will determine this so it's hard to answer with a single number. Obviously, the trees start sucking carbon up as soon as they're planted, but the net benefit depends on the situation. e.g. Has the land been cleared to plant the trees or was it already bare? If the latter, the benefits are immediate, but if clearance is involved, there would be a bunch of carbon lost through the soil compared to before (e.g. through erosion etc.). It also depends on the tree species. Things like pine and Eucalypts are fast growing so are faster at taking carbon up, but also reach their limits sooner. Soil conditions matter too. e.g. nutrient levels will determine the rate of tree growth, existing carbon content and soil structure will determine how much carbon is stored in the soils or lost from the soils, pH levels matter, microbial activity matters too -- most tree species require mutualistic microbial partners underground, particularly fungi, which help them source nutrients from the soil in exchange for sugars from the tree. And the amount of carbon expended to initiate the planting matters of course.
So a super question, but a super hard question to answer simply. There's a typical ecologists answer for you: it depends! :)
Excellent, we need the right trees in the right places., and as you discuss it's much more complicated than many people seem to think
Thanks Juliet -- absolutely!
Great post. We’re suffering the double failure here of past deforestation and single species replanting. Any disease, unusual weather or pests like pine beetle have extreme effects which can be minimized by planting pioneers. Sadly not a short term climate solution.
Thanks David! Yes, single species monocultures are an extremely fragile option in a changing climate. Disease/pest outbreaks are already proving to be a major problem for such systems, and they are only going to get worse. There's a real tradeoff to be had here with regard to short-term/near-term benefits, which come with long-term costs vs. less effective near-term benefits, but greater long-term benefits. I think a compromise can be met with careful planning.
Cheers to you too, Jonathan! Thanks for the reply.
Johan Rockström, in the interview below, mentions that a big part of the carbon that that trees capture is actually a stress response, and therefore we should not rely on forests. In fact, he says, some forests already have become a source of carbon instead of being sinks, although we do not know yet exactly the reason. But a healthy planet in equilibrium, he says, takes up as much carbon dioxide in the the photosynthesis as it releases through respiration.
What do you think of it?
The part of the interview where he talks about it: https://youtu.be/lLq8e73-FAw?feature=shared&t=895
Thanks Lazaros! Yes, interesting point. I think the key point is that we don't know how much buffering capacity forests have. How much more can they take? The net emitters are emitting because of a combination of things, including unsustainable forestry practices, fire regimes that are enabled due to forest modification etc. So it's not that healthy, natural functioning forests are net emitters necessarily, it's that they become net emitters when they have been modified in some way or another. However, if climate change continues to increase fire regimes and disease outbreaks like bark beetle in Canadian forests etc., then we don't know the thresholds of when forests (even unmodified forests) shift from being sinks to sources of carbon. Either way, forests are just part of the toolbox for the carbon problem, given there is so so much more carbon in the atmosphere than there was historically due to fossil fuel use. Cheers!
Great post Jono, I think it's really important that we distinguish between mitigating carbon in the atmosphere that came from land use change and that from fossil carbon. As is referenced in the article below "While the carbon atom in the tree is the same as the carbon atom from burned fossil fuels, that’s where the similarity ends. The fossil carbon the tree is purportedly mitigating is a separate and additional source." So notwithstanding the points you made, its crucial to understand that planting a tree does not mitigate a gram of fossil carbon only the carbon emitted when the tree that was there before was chopped down. https://theconversation.com/were-burning-too-much-fossil-fuel-to-fix-by-planting-trees-making-net-zero-emissions-impossible-with-offsets-217437
Thanks Mike! Very good point. Thanks for sharing. I particularly like your ending: "Deforestation has to be reversed, and more trees must be planted to sequester the carbon emitted through past land-use changes. But planting trees instead of stopping fossil emissions is not the answer. Planting trees as well as not emitting fossil carbon is the only solution."
And PS: Rod Carr covers this topic well here from a NZ perspective: https://youtu.be/I1_gdvNtGXk?si=zmlJiHAJi6d8eyww
Jonathan, we are on the same page. Sweden converted huge areas of bog and wetlands to forest (not for "climate" reasons but for production reasons) the last hundred years, and in most cases that has lead to decreased carbon storage.
Interesting -- thanks for sharing, Gunnar. So many examples of such initiatives.
Do you have preferred policy mechanisms for stopping deforestation / incentivizing new growth?
I don't have a single preferred option to be honest. Disclaimer, I'm not an expert on this. But it's context dependent, really depending on the economic situation of the particular location. Many such things come down to $$. So having the right economic incentives is key. Whether bottom-up or top-down is more effective again depends on the situation. etc. Perhaps I should get an expert in to post on such a topic?
It's the question that always comes to mind for me at least, reading posts like this one. We can design all the perfect tools for restoration. But we still have to figure out how to reward people for stewarding forests more than we reward, say, cattle ranching.
Definitely, Chris. I always say if you want to make the biggest difference, do social science or economics.
Good article. Jonathan covers a lot of the issues surrounding reforestation. It's NOT just a matter of sticking seedlings in the ground.
However, reforestation is the ONLY proven method that exits for actually pulling CO2 out of the atmosphere"at scale". Everything else, is basically impossible with any realistic technology we can develop and deploy at scale in the next 50 years.
Reforestation can work. But there's a BIG price.
040 - What if I told you there was a way to pull enough CO2 out of the atmosphere to cool the planet down over the next century. How many lives would you be willing to sacrifice to save the FUTURE? - On Reforestation.
https://richardcrim.substack.com/p/the-crisis-report-40
Thanks Richard. Already replied to your note. But appreciate you diving in. Looking forward to exploring your newsletter more.
Another great piece! I have a question about the section where you mention that “monocultures of fast-growing species like pines tend to get cut down after a relatively short time period (or begin to die off) and so do not end up being long-term carbon sequestration solutions.” Is there a timeline for how long it takes for a single reforestation attempt to become net positive in terms of carbon sequestration? Do we get benefits immediately after the trees have been planted, or does it take a while to take effect? Thanks for your insight and expertise!
Thanks very much, Carrie! Good question. There are a bunch of factors that will determine this so it's hard to answer with a single number. Obviously, the trees start sucking carbon up as soon as they're planted, but the net benefit depends on the situation. e.g. Has the land been cleared to plant the trees or was it already bare? If the latter, the benefits are immediate, but if clearance is involved, there would be a bunch of carbon lost through the soil compared to before (e.g. through erosion etc.). It also depends on the tree species. Things like pine and Eucalypts are fast growing so are faster at taking carbon up, but also reach their limits sooner. Soil conditions matter too. e.g. nutrient levels will determine the rate of tree growth, existing carbon content and soil structure will determine how much carbon is stored in the soils or lost from the soils, pH levels matter, microbial activity matters too -- most tree species require mutualistic microbial partners underground, particularly fungi, which help them source nutrients from the soil in exchange for sugars from the tree. And the amount of carbon expended to initiate the planting matters of course.
So a super question, but a super hard question to answer simply. There's a typical ecologists answer for you: it depends! :)
Thanks for the thorough answer! I definitely learned a lot through this piece!