No twitter for me - what did you say?
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Forrest Fleischman @ForrestFleisch1 20h Some context: A couple weeks ago a team I am a part of published a paper demonstrating the failure of long-term planting programs in India nature.com/articles/s41893-0… or ungated: conservancy.umn.edu/bitstrea…
Limited effects of tree planting on forest... Nature Sustainability - Large-scale tree planting programmes have been implemented or planned for areas around the world suffering from deforestation, but this study presents evidence that such...
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Forrest Fleischman @ForrestFleisch1 20h This follows an earlier paper that discussed some of the common failings of tree planting programs more broadly: cedarhimalaya.org/images/Fle… 3 19 2 319
Forrest Fleischman @ForrestFleisch1 20h This work has received some attention in the press, and it seems like the folks who've been contacting me all read the same excellent story by @BenjiSJones vox.com/down-to-earth/226793…
The surprising downsides to planting trillions of trees "We’re not going to plant our way out of climate change."
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Forrest Fleischman @ForrestFleisch1 20h The people who contacted me are in California and appear to be Silicon Valley businesspeople who are entranced with the idea of tree planting as a climate solution. I have no reason to doubt they are genuine & mean well. 3 21 5 480
Forrest Fleischman @ForrestFleisch1 20h Both have created web-based businesses where you can pay them to plant trees. The websites share a few characteristics. First, both clearly and directly reference the work of @CrowtherLab about a trillion trees as being their inspiration. 3 17 0 316
Forrest Fleischman @ForrestFleisch1 20h This is in spite of the serious doubts about the scientific validity of the trillion trees idea science.org/doi/10.1126/scie… and also goes against Bastin & Crowther's subsequent public statements.
Comment on “The global tree restoration potential” Bastin et al.’s estimate (Reports, 5 July 2019, p. 76) that tree planting for climate change mitigation could sequester 205 gigatonnes of carbon is approximately five times too large. Their analysis...
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Forrest Fleischman @ForrestFleisch1 20h But its actually quite consistent with their initial press interviews. Bastin, Crowther, and their coauthors still have alot of work to undo the repercussions of their exaggerated initial claims (which they have since disavowed, including in the Vox piece linked above) 2 18 0 320
Forrest Fleischman @ForrestFleisch1 20h Second, both websites make other dubious claims about tree planting. For example, one argues that planting more trees will increase the oxygen in the atmosphere. 1 14 0 282
Forrest Fleischman @ForrestFleisch1 20h This isn't really true - while oxygen cycles through trees on balance trees and forests are not really a net source of oxygen (because their decomposition uses up about the same amount of oxygen they create) and anyway, the planet is at no risk of running out of oxygen... 4 34 3 514
Forrest Fleischman @ForrestFleisch1 20h Third, both sites sell tree planting as a way to offset personal carbon emissions. There is alot of debate in my field about the validity of this kind of offsets, too much for twitter, but a few key problems are: 1 27 4 514
Forrest Fleischman @ForrestFleisch1 20h 1. Land use change is already a major source of carbon emissions. The best way to think about forests absorbing new carbon is to think about this as offsetting carbon emissions lost from past forest destruction. 2 75 12 718
Forrest Fleischman @ForrestFleisch1 20h 2. Relatedly, there isn't enough space on the planet for natural ecosystems to absorb more than a small share of fossil fuel emissions. 6 99 11 723
Forrest Fleischman @ForrestFleisch1 20h 3. Trees planted today will absorb carbon in the future. Your emissions today start heating the planet today. 4 210 17 1,155
Forrest Fleischman @ForrestFleisch1 20h 4. Tree planting projects often fail, so if you plant trees rather than reduce your emissions, you might actually be doing nothing. 3 154 7 986
Forrest Fleischman @ForrestFleisch1 20h A project whose goal is to plant a certain number of trees is particularly vulnerable to failure because its counting the wrong thing. 2 46 3 557
Forrest Fleischman @ForrestFleisch1 20h If the goal is to absorb emissions, we should count the carbon, not the trees. A few small large absorb more carbon than a bunch of little trees. 9 69 5 754
Forrest Fleischman @ForrestFleisch1 20h When we plant trees with carbon uptake or forest restoration as a goal, we don't try to maximize the number of trees. We try to maximize long-term carbon uptake, and this might actually mean planting fewer trees up front besjournals.onlinelibrary.wi…
Guidance for successful tree planting initiatives Tree planting, along with other strategies to increase tree cover in appropriate locations and contexts, can make a valuable contribution to ensuring the ecological and social well-being of our...
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Forrest Fleischman @ForrestFleisch1 20h In addition, if we focus on the number of trees, we lose sight of the relationships that support long-term forest sustainability. Do the people who live near the trees benefit from them? Do they get to make decisions about them? Will the site support trees in a warming climate? 7 83 7 845
Forrest Fleischman @ForrestFleisch1 20h If the company's goal is to plant a number of trees, they are less likely to pay attention to the broader context that supports long-term tree growth. 2 30 2 517
Forrest Fleischman @ForrestFleisch1 20h To me a focus on the number of trees, as opposed to, say, the well-being of the people growing the trees, the carbon stored in them, or the biodiversity they support, is a signal that the tree growing project is not well thought through. I can't support or advise such projects. 3 158 12 1,165
Forrest Fleischman @ForrestFleisch1 20h What to do instead? There are lots of organizations in the world working to improve land management in local contexts in ways that lead to win-win outcomes. More carbon, more biodiversity, and more human well-being. Oftentimes the key interventions aren't even biophysical 10 86 4 734
Forrest Fleischman @ForrestFleisch1 20h For example, sometimes better restoration outcomes might be the result of land reform, not distributing seedlings. 6 54 6 615
Forrest Fleischman @ForrestFleisch1 20h Maybe this doesn't lend itself to a nice marketing slogan, but I hope these efforts shift in this direction. What they are doing now appears to be at best a waste of time & money, and at worst a dangerous greenwash. 5 30 2 620
Forrest Fleischman @ForrestFleisch1 20h I'll just add that lots of these good programs DO plant trees. Planting trees is wonderful. The right tree in the right place brings many benefits. But the wrong tree in the wrong place is harmful. We should focus on our overall goals, not on the number of trees we plant. 9 123 6 1,253
Forrest Fleischman @ForrestFleisch1 20h And planting trees does not give you an indulgence to burn fossil fuels the rest of the day.