Arbor Day. It’s good thing, right? We can trust experts at Extension, NRCS, State Forestry and the Forest Service to help people plant trees where it’s a good idea, and not plant trees where it’s not, right? Well, thanks to climate change and the Satellite Gaze, some have gotten the opposite impression. Tree planting has become controversial through what I call “Satellite Ping-Pong.” It’s an infinite game of discussing different assumptions about enormous and global questions by volleying between specific places and concerns. But the people directly involved in making decisions, including landowners and communities, are never involved in the game. Others claim to speak for them with varying degrees of accuracy.
First, someone does a study on what tree planting might do around the world. This involves innumerable assumptions and pretty much no input from people as to whether they want trees or not. Or whether trees would live. Or get eaten by ungulates, livestock, insects, fall prey to disease, or get burned up, or any of the (to paraphrase Hamlet) “the thousand natural shocks that arboreal life is heir to.”
This was in Science in 2019:
The restoration of trees remains among the most effective strategies for climate change mitigation. We mapped the global potential tree coverage to show that 4.4 billion hectares of canopy cover could exist under the current climate. Excluding existing trees and agricultural and urban areas, we found that there is room for an extra 0.9 billion hectares of canopy cover, which could store 205 gigatonnes of carbon in areas that would naturally support woodlands and forests. This highlights global tree restoration as one of the most effective carbon drawdown solutions to date. However, climate change will alter this potential tree coverage. We estimate that if we cannot deviate from the current trajectory, the global potential canopy cover may shrink by ~223 million hectares by 2050, with the vast majority of losses occurring in the tropics. Our results highlight the opportunity of climate change mitigation through global tree restoration but also the urgent need for action.
I have to give them credit, they did admit “we really don’t have a clue if trees will live or not due to climate change,” so at least one source of tree death was taken into account. They also say “one of the most effective,” not “let’s keep emitting fossil carbon.”
You might call this the “serve” in Satellite Ping Pong. Then there started a vast array of critiques. What fascinates me is the way that the stories talk about the real places I know, and who has the authority to speak. For example, this by the Yale 360 pub (well, it’s kind of Yale’s, but kind of separate).
Because of climate change, forests are increasingly vulnerable to destruction by drought, fire, insects, diseases, and storms, which releases carbon back into the atmosphere. Recent research shows that large areas of the American West may have permanently lost their forest cover. Droughts, wildfire, and insect and disease outbreaks are becoming more frequent, and forests are being replaced by grassy shrublands after these disturbances, mostly because it’s now too hot and dry for new generations of saplings to survive. A review paper published in Science last year shows that these threats, although significant and intensifying, aren’t always well understood and are difficult to compensate for. It’s hard to predict how many trees they’ll kill in the near future and how much carbon that will put into the atmosphere, but it’s likely to be considerable.
Not only might tree planting fail to reliably sequester carbon, trees can also heat the atmosphere more than many other habitat types. Kathleen Smart, a post-doctoral researcher at Rhodes University in South Africa, says that replacing surfaces like grasslands or deserts —which, being pale, reflect more solar radiation into outer space — with relatively dark-colored tree plantations can have a heating effect on a local level, and that regional-scale land-use changes have been shown to affect climate and rainfall patterns
As a veteran of efforts to reforest dry areas in the 80’s, I’m surprised that the solution to not getting trees back is now “give up, it must be climate change.” Before we thought “it’s a coincidence of not having a good seed year when the soil is still exposed.”
And I can only speak for the grasslands and deserts I know, but they are not likely to grow trees except along streams (why not replace dying cottonwoods if they aren’t reproducing themselves?) and for windbreaks. Windbreaks help reduce energy use, produce wildlife habitat, and so on. But not at any scale to help with climate change. And that’s OK.
Forrest Fleischman was quoted in this one:
To be clear, critics of the campaign are still fans of trees. They still think forests play a role in solving the climate crisis — their skepticism mostly centers around efforts to plant trees in places they weren’t before, or to plant large swaths of a single species to essentially create “tree plantations” instead of real forests. Another big concern surrounding the call for planting a trillion trees is that it could distract from other efforts to slow down climate change, like stopping fossil fuel pollution and deforestation in the first place.
“You don’t need to plant a tree to regenerate a forest,” Fleischman tells The Verge. Forests can heal on their own if they’re allowed to, he says, and these forests end up being more resilient and more helpful in the climate fight than newly planted plots of trees. He argues that the best way to ensure there are enough trees standing to trap the carbon dioxide heating up the planet is to secure the political rights of people who depend on forests — primarily indigenous peoples whose lands are frequently encroached upon by industry and governments.
There is research backing him up. The world’s leading authority on climate science, the United Nations Intergovernmental Panel on Climate Change (IPCC), has recognized that when local communities’ land rights are jeopardized, it poses risks to both people and the planet.
I disagree with Forrest on “forests can heal on their own”. If we take a place like the Hayman, where the nearest seed sources are far away, I think it’s better to have tree cover sooner- not just for climate, but for wildlife, watershed (holding soils) and so on. Sidenote: there are exactly the same “local people” arguments questioning another international initiative, 30 x 30.
And I guess the argument that planting trees (as described in the Ping Pong discourse) distracts from stopping fossil fuel pollution is strange. You could say that about any non-energy interventions. So let’s just let the land-use types bow out… including the anti-pastoralist crowd, 30 x 30 and so on. We’ll just work on resilience, thank you. Whoops, I guess we need to plant some trees for that..