How the Great Green Wall is holding back the Sahara desert(kottke.org)
kottke.org
How the Great Green Wall is holding back the Sahara desert
https://kottke.org/24/03/how-the-great-green-wall-is-holding-back-the-sahara-desert
61 comments
https://en.wikipedia.org/wiki/Great_Green_Wall_(Africa)#Risk...
> As of 2023, the Great Green Wall was reported as "facing the risk of collapse" due to terrorist threats, absence of political leadership, and insufficient funding. “The Sahel countries have not allocated any spending in their budgets for this project. They are only waiting on funding from abroad, whether from the European Union, the African Union, or others.” said Issa Garba, an environmental activist from Niger, who also described the 2030 guideline as an unattainable goal. Amid the existing stagnation, a growing number of voices have called for scrapping the project.
> As of 2023, the Great Green Wall was reported as "facing the risk of collapse" due to terrorist threats, absence of political leadership, and insufficient funding. “The Sahel countries have not allocated any spending in their budgets for this project. They are only waiting on funding from abroad, whether from the European Union, the African Union, or others.” said Issa Garba, an environmental activist from Niger, who also described the 2030 guideline as an unattainable goal. Amid the existing stagnation, a growing number of voices have called for scrapping the project.
Further discussion here:
https://news.ycombinator.com/item?id=39466851
Thanks! Macroexpanded:
Africa is building a Great Green Wall to prevent expansion of the Sahara - https://news.ycombinator.com/item?id=39466851 - Feb 2024 (68 comments)
Africa is building a Great Green Wall to prevent expansion of the Sahara - https://news.ycombinator.com/item?id=39466851 - Feb 2024 (68 comments)
Nearly all of the Algerian Saharan territory is surrounded by state made wall (dune) of 2-5 meters high.
Morocco also has similar and several walls: https://en.wikipedia.org/wiki/Moroccan_Western_Sahara_Wall
If there is money and resources to build and maintain such walls, there should be more will and good intentions to build green walls which are more useful.
Morocco also has similar and several walls: https://en.wikipedia.org/wiki/Moroccan_Western_Sahara_Wall
If there is money and resources to build and maintain such walls, there should be more will and good intentions to build green walls which are more useful.
Q: As an outsider, how is one to tell if this approach is the right one?
There seems to be a certain amount of dissent.
"Mass tree-planting programs in the desert often cause lasting damage to the ecosystems they are purportedly trying to repair." https://www.noemamag.com/if-the-desert-was-green/
"Israel’s Yatir Forest has been hailed as a green refuge in the Negev that is helping fight climate change. But some Israeli ecologists now contend that it has wiped out important desert ecosystems and shows that forestation projects are not always an unalloyed environmental good." https://e360.yale.edu/features/in-israel-questions-are-raise...
There seems to be a certain amount of dissent.
"Mass tree-planting programs in the desert often cause lasting damage to the ecosystems they are purportedly trying to repair." https://www.noemamag.com/if-the-desert-was-green/
"Israel’s Yatir Forest has been hailed as a green refuge in the Negev that is helping fight climate change. But some Israeli ecologists now contend that it has wiped out important desert ecosystems and shows that forestation projects are not always an unalloyed environmental good." https://e360.yale.edu/features/in-israel-questions-are-raise...
My question is are there downstream effects? The planting techniques are fascinating but the water that they are capturing surely was going some where, right? However little the stream may be, how do they do this without messing up people who are downstream?
It doesn't necessarily work like that. Vegitation can cause more rain rather than just taking water from elsewhere. A striking example is the Loess plateau, in China which went from dessert to green. Article mentioning it:
https://www.theguardian.com/environment/2021/mar/20/our-bigg...
https://www.theguardian.com/environment/2021/mar/20/our-bigg...
I have to imagine a lot of it evaporated because it wasn't being captured, and then others became runoff that may have gone out to sea if it had been raining too hard.
They discuss this in the video, and if you watched it you’ll notice that they’re doing these projects along a major river near the ocean. They only capture 15% or so of what is today run off into the river. Rivers ultimately flow into the ocean. There is no one really downstream depending on that small percent of runoff.
I did watch the video but must have missed the 15% number. Thanks.
Np I’d also notice the placement along the river and the river proximity to the ocean. They specifically call out not over harvesting the water. I’m pretty impressed as an engineer how well thought out the program is.
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hard to imagine a downstream effect that's worse than becoming part of the sahara
I think the concern is downstream effects negative to areas and people far away.
Like how the Sahara feeds the Amazon rainforest. https://www.nasa.gov/centers-and-facilities/goddard/nasa-sat...
i.e. greening your land might lead to browning mine.
Like how the Sahara feeds the Amazon rainforest. https://www.nasa.gov/centers-and-facilities/goddard/nasa-sat...
i.e. greening your land might lead to browning mine.
ah right, but they're not looking to reduce the sahara, but stop it... so in theory they're avoiding any new downstream effects? though I guess it's possible that some necessary process results in the sahara's growth? that's not my understanding though, part of the reason it grows is due to surrounding areas becoming more susceptible to desertification through agriculture
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A lot of interesting takes in the comments where growing more plants will somehow cause ecological disaster. The only exception I can see is diverting water to support it. Otherwise, I have never heard such a thing.
Just off the top of my head: kudzu, skull weed, and tamarisk. I’m sure there are many more examples. Just because you are unaware of something doesn’t exist.
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Those are invasive weeds. I don’t think they compare well to the native grass and citrus trees they are growing.
Reminds me of the proposal to flood the Qattara sea: https://news.ycombinator.com/item?id=35957814
I think the big difference here is that the Qattara Sea would be a major engineering project involving specialized skills and machinery.
The Great Green Wall is more open in that anyone can contribute to its construction. All you need is a shovel and some seeds.
The Great Green Wall is more open in that anyone can contribute to its construction. All you need is a shovel and some seeds.
Citation required and requested.
I can plant a hundred trees, keep them up for a year, and find a hundred tree stumps in two. I genuinely would like to know where on the spectrum this is:
- This is a fools' errand
- This requires constant upkeep and detailed construction
- This requires mild upkeep
- This is self-sustaining, can be done with a shovel + seeds, and once started, is self-sustaining, with the forest turning the Sahara green
I can plant a hundred trees, keep them up for a year, and find a hundred tree stumps in two. I genuinely would like to know where on the spectrum this is:
- This is a fools' errand
- This requires constant upkeep and detailed construction
- This requires mild upkeep
- This is self-sustaining, can be done with a shovel + seeds, and once started, is self-sustaining, with the forest turning the Sahara green
It is designed by researchers who have been studying this for a while. At least for the near term the upkeep is worth it because people who previously no had prospects can now grow enough food to live on. You have to keep it up, but keeping it up means you can eat so the constant upkeep shouldn't be a problem so long as you are healthy. (culture or something is needed to deal with those who because of age or injury are not able to keep it up)
The real question is if in 50 years - as the current people use the fact that they have food and some extra invest in education for their kids, and so the kids move away to better city jobs. Those that remain likely love agriculture, but will be looking for ways use tractors to do the hard jobs. This doesn't seem to scale to large tractor operations. Those researchers thus need to look ahead to what follows this in 50 years.
The real question is if in 50 years - as the current people use the fact that they have food and some extra invest in education for their kids, and so the kids move away to better city jobs. Those that remain likely love agriculture, but will be looking for ways use tractors to do the hard jobs. This doesn't seem to scale to large tractor operations. Those researchers thus need to look ahead to what follows this in 50 years.
This requires constant upkeep. The goal is to structure it so the local community is incentivized to invest that upkeep, but it's not just gonna happen all by itself. The goal is indeed a self-sustaining ecosystem, but one with human participation. If you want more detail, a good keyword is "Farmed Managed Natural Regeneration"
That keyword also makes it pretty clear it's more than a shovel and some seeds :)
And, fwiw, your request made me look at the thegreatgreenwall.org, and... good god. It is one of the lowest-information sites I've seen in a while. You could spend hours on there and learn nothing. https://thegreatgreenwall.org/science-and-the-ggw is as far as I can tell the only concrete part of this piece.
A much better starting point if you care about a bit more than feel-good vibing is https://www.unccd.int/our-work/ggwi
And that site makes it again abundantly clear that this is a very large scale project. The difference from the Qattara Sea project is that it actually managed to gin up multinational corporation, and that it takes a long term lens (as opposed to "IDK, let's flood this, rest's gonna work out" of the various seaflooding projects). And, most importantly, because it integrates the local communities in the project.
The last part matters because any such project is far from "fire and forget", and you need a strong local stake in any such project for it to succeed.
That keyword also makes it pretty clear it's more than a shovel and some seeds :)
And, fwiw, your request made me look at the thegreatgreenwall.org, and... good god. It is one of the lowest-information sites I've seen in a while. You could spend hours on there and learn nothing. https://thegreatgreenwall.org/science-and-the-ggw is as far as I can tell the only concrete part of this piece.
A much better starting point if you care about a bit more than feel-good vibing is https://www.unccd.int/our-work/ggwi
And that site makes it again abundantly clear that this is a very large scale project. The difference from the Qattara Sea project is that it actually managed to gin up multinational corporation, and that it takes a long term lens (as opposed to "IDK, let's flood this, rest's gonna work out" of the various seaflooding projects). And, most importantly, because it integrates the local communities in the project.
The last part matters because any such project is far from "fire and forget", and you need a strong local stake in any such project for it to succeed.
Thank you! I received three responses.
1) One pointing to the linked promo video designed to give feel-good vibes, claiming that's a citation. (fnordpiglet)
2) One without citations, just claiming this was designed by "researchers" and I should take that on the double-authority (bluGill)
3) And yours, which is helpful and points to an actual set of citations!
Thank you for that!
Footnote: There was a point in history when slashdot, and then reddit, were populated by intelligent discussions. At some point, there was a cliff. I enjoy HN, but I feel like we're heading for that cliff. I've seen this dynamic more and more. There are good people like you still left here, but the signal-to-noise ratio is dropping....
1) One pointing to the linked promo video designed to give feel-good vibes, claiming that's a citation. (fnordpiglet)
2) One without citations, just claiming this was designed by "researchers" and I should take that on the double-authority (bluGill)
3) And yours, which is helpful and points to an actual set of citations!
Thank you for that!
Footnote: There was a point in history when slashdot, and then reddit, were populated by intelligent discussions. At some point, there was a cliff. I enjoy HN, but I feel like we're heading for that cliff. I've seen this dynamic more and more. There are good people like you still left here, but the signal-to-noise ratio is dropping....
All indications are this is supported by serious research from universities. Though I will agree that if you want to go deeper than a conversation level you will need to find who. I would assume the the researchers are writing most of this up in language others than English. In fact if you found a lot of information in English I would be very concerned as the people doing this do not speak English. They may publish some in English as well, but if the majority isn't in the local language (which might be translated or not) there is a problem.
Speculation is very unhelpful, as are uncited claims. It's just not.
FYI: Your assumption is wrong. The language used for instruction in most universities in ECOWAS is either English or French, and mostly English. If you're talking about the research, or anything vaguely like leadership, all people doing this will speak primarily English as the lingua franca.
You can figure that out with by googling this:
https://duckduckgo.com/?t=ffab&q=top+universities+ecowas&ia=...
And visiting their web pages.
The related problem is that e.g. Nigerian English or Ghanian English isn't the same as British or American, and academic journals do discriminate on this sort of thing, very explicitly.
FYI: Your assumption is wrong. The language used for instruction in most universities in ECOWAS is either English or French, and mostly English. If you're talking about the research, or anything vaguely like leadership, all people doing this will speak primarily English as the lingua franca.
You can figure that out with by googling this:
https://duckduckgo.com/?t=ffab&q=top+universities+ecowas&ia=...
And visiting their web pages.
The related problem is that e.g. Nigerian English or Ghanian English isn't the same as British or American, and academic journals do discriminate on this sort of thing, very explicitly.
The citation is the video linked to that you’re commenting on. This isn’t tree planting greenwashing. This is engineered and planned, but it involves local people tending the land and turning it into continuously productive soil for profit. Greenwashing tree planting fails because it’s untended unplanned work. In this video they go through all the steps they take, including analyzing contours and building the water retention berms along them, the phasing of the work from basic planting to trees with crops interspersed etc. It’s really worth watching it.
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It seems crazy to me that after we've had so many unintended consequences preventing earth's natural processes using technology, the same crowd is now celebrating using technology to prevent yet another of earth's natural processes. Regardless of your position on the Sahara desert, it's been growing since Roman times.
Personally, I'm in favor of the use of technology to affect the planet, but it seems to me that the public reception to these ideas is mostly around who's doing the deed. Often, when someone in a rich country proposes something like this, the argument will be something about capitalism. However, when a poor country does it, despite it also being about wealth at the end of the day, it's lauded. Now again, I'm totally in favor of all these efforts and totally understand why people do it. It's just a duality I've noticed; and I'm not sure what to think about it.
Personally, I'm in favor of the use of technology to affect the planet, but it seems to me that the public reception to these ideas is mostly around who's doing the deed. Often, when someone in a rich country proposes something like this, the argument will be something about capitalism. However, when a poor country does it, despite it also being about wealth at the end of the day, it's lauded. Now again, I'm totally in favor of all these efforts and totally understand why people do it. It's just a duality I've noticed; and I'm not sure what to think about it.
Why does that seem crazy to you? Some artificial interventions in the earth's natural processes are bad for humans (global warming, increased rate of desertification) and some interventions are good for humans (increasing land available for sustainable food production, killing malaria carrying mosquitos).
There isn't some "human interventions good/human interventions bad" duality. Some are good some are bad. We should stop doing to bad things and do more of the good things. We should continuously audit for new effects caused by our actions are adjust accordingly to achieve the best outcomes for human life.
There isn't some "human interventions good/human interventions bad" duality. Some are good some are bad. We should stop doing to bad things and do more of the good things. We should continuously audit for new effects caused by our actions are adjust accordingly to achieve the best outcomes for human life.
Exactly this. I think we have to wrestle with the fact that, as consumers of media, we sometimes become possessed by Trick Question Syndrome. So even if nothing about the facts indicates than an intervention is bad, treating it like at trick question feels like healthy skepticism.
Do hand-dug berms planted with native and non-invasive plants count as technology?
And is increasing desertification one of earth's natural processes or is it an effect of technology, specifically technology we've used to pull massive amounts of carbon out of the ground and add it to the atmosphere?
Not trying to be hostile, just questioning some of your assumptions.
And is increasing desertification one of earth's natural processes or is it an effect of technology, specifically technology we've used to pull massive amounts of carbon out of the ground and add it to the atmosphere?
Not trying to be hostile, just questioning some of your assumptions.
Hand-dug berms are certainly technology, but perhaps not “high technology”.
And desertification is a natural process, see the Middle East or the Sahara itself, but perhaps accelerated by human impact.
And desertification is a natural process, see the Middle East or the Sahara itself, but perhaps accelerated by human impact.
Technology means the application of scientific knowledge for practical purposes. It is a technology. If this is good or bad, is a rather Victorian notion called the appeal to nature.
Hard to imagine a framework for thinking about this where "hand-dug" matters, but unfortunately I think it comes down to things like this.
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Humans and technology have been around a lot longer than Rome. Do you think desertification is a completely natural process that has nothing to do with the humans who live in the area and what they do with the land?
Yes. There were deserts before humans.
It's not about "who does the deed". It's about who accrues the benefits, and who has a stake.
Without a strong local stake, the only projects that work are resource extraction projects. These have a tendency to create dependencies, and strong political instability.
There's also the fact that many technocratic proposals from rich countries never progress past first order thinking: "Trees missing, add trees here". Again, a function of skin in the game - rich nations overwhelmingly operate on a form of capitalism that prioritizes short term wins, and they're not around for the cleanup after that. This is why you want a local stake - not due to theoretical arguments around capitalism or colonialism, but because you want to make sure the people who own the consequences are part of the process. Which usually leads to better outcomes.
Without a strong local stake, the only projects that work are resource extraction projects. These have a tendency to create dependencies, and strong political instability.
There's also the fact that many technocratic proposals from rich countries never progress past first order thinking: "Trees missing, add trees here". Again, a function of skin in the game - rich nations overwhelmingly operate on a form of capitalism that prioritizes short term wins, and they're not around for the cleanup after that. This is why you want a local stake - not due to theoretical arguments around capitalism or colonialism, but because you want to make sure the people who own the consequences are part of the process. Which usually leads to better outcomes.
> using technology to prevent yet another of earth's natural processes.
Agriculture prevents a lot of earth's natural processes and has been doing so for millennia. We, as humans living in a relatively advanced civilization prevent earth's natural process just by living an urban area. I really don't see your point.
Agriculture prevents a lot of earth's natural processes and has been doing so for millennia. We, as humans living in a relatively advanced civilization prevent earth's natural process just by living an urban area. I really don't see your point.
Everyone is okay with building walls to hold off rising sea waters. Why is this any different?
> using technology to prevent yet another of earth's natural processes
I mean it's literally just planting trees, grasses, and shrubs. This isn't dumping a cargo ship of iron filings into the sea or putting a solar sail in front of the sun, it's putting seeds in the ground. If you want to call that "technology" I suppose it's technically true, but it's almost laughable.
I mean it's literally just planting trees, grasses, and shrubs. This isn't dumping a cargo ship of iron filings into the sea or putting a solar sail in front of the sun, it's putting seeds in the ground. If you want to call that "technology" I suppose it's technically true, but it's almost laughable.
I respect the right of Africa to try and reforest, but logically the most likely outcome is that the Amazon will start to die from the lack of the 30 million tons of dust and sand that fall on the Amazon each year from the Sahara.
Should Africa's desert be preserved to feed the Amazon? That's a question humanity seems ill equipped to answer.
Should Africa's desert be preserved to feed the Amazon? That's a question humanity seems ill equipped to answer.
The Sahara desert is 3.5 million square miles. That will never be re-forested.
Never is a pretty long time. One of my favorite authors: Doris Lessing, wrote a book called: "Mara and Dan" which has a very interesting take on climate change. I would recommend all of her books to anyone who wants to stretch their perception of our world.
Okay, sure, if you look at geologic timescales then eventually Africa will move and the region of northern Africa will cease to be desert.
Within a human timescale, I think "never" is an acceptable term.
Atmospheric circulation means that the latitude of the Sahara is blasted with cool dry air from the upper atmosphere. Humans planting trees might slow the spread of the desert, but will not vanquish it.
To disrupt the effects of atmospheric circulation (ie Hadley cells) creating deserts at those latitudes, you'd need mountain ranges and oceans.
https://en.m.wikipedia.org/wiki/Hadley_cell
Within a human timescale, I think "never" is an acceptable term.
Atmospheric circulation means that the latitude of the Sahara is blasted with cool dry air from the upper atmosphere. Humans planting trees might slow the spread of the desert, but will not vanquish it.
To disrupt the effects of atmospheric circulation (ie Hadley cells) creating deserts at those latitudes, you'd need mountain ranges and oceans.
https://en.m.wikipedia.org/wiki/Hadley_cell
"For several hundred thousand years, the Sahara has alternated between desert and savanna grassland in a 20,000-year cycle caused by the precession of Earth's axis (about 26,000 years) as it rotates around the Sun, which changes the location of the North African monsoon."
https://en.wikipedia.org/wiki/Sahara#:~:text=For%20several%2....
https://en.wikipedia.org/wiki/Sahara#:~:text=For%20several%2....
Why are we working in human timescales? It's like saying the sun will never burn out because humans won't be around to see it happen.
To me, that's a pretty bold and naive claim.
To me, that's a pretty bold and naive claim.
It is cultural human hubris to bother, in any way whatsoever, to be worried about the sun burning out. It’s an interesting curiosity but we your life, if you lived to be 2000 years old (you won’t), you will have moved yourself 0.0000571428% closer to the time when that will happen. We DO need to actually be worried about our planet overheating, our agricultural spaces becoming despoiled, and other things that can actually happen in our lives. One of these things is not like the other.
Because this project is about humans and the environment's impact on them, and what they can do to improve it. So naturally human timescales are the measure on which we judge it. What happens in 10 million years is not something we can even pretend to comprehend or influence in a meaningful way. But what happens in the next 100 is.
Not with that attitude.
Found the Shai-Hulud.
> logically the most likely outcome is that the Amazon will start to die
This seems like a very large leap of reasoning to "logically" make.
My understanding is that Saharan dust clouds carry phosphorus across the Atlantic, which nourish the Amazon.
It doesn't follow that Africa stopping the expansion of the Sahara will kill this cycle. The Sahel has historically been used for agriculture (with periods of massive drought in between) and preventing the Sahara from expanding into it does not mean erasing the rest of the Sahara.
This seems like a very large leap of reasoning to "logically" make.
My understanding is that Saharan dust clouds carry phosphorus across the Atlantic, which nourish the Amazon.
It doesn't follow that Africa stopping the expansion of the Sahara will kill this cycle. The Sahel has historically been used for agriculture (with periods of massive drought in between) and preventing the Sahara from expanding into it does not mean erasing the rest of the Sahara.
> I respect the right of Africa to try and reforest, but logically the most likely outcome is that the Amazon will start to die from the lack of the 30 million tons of dust and sand that fall on the Amazon each year from the Sahara.
Math. Stopping the Sahara from expanding doesn't change how much dust and sand are going over to the Amazon, it just caps it at the current amount.
Math. Stopping the Sahara from expanding doesn't change how much dust and sand are going over to the Amazon, it just caps it at the current amount.
There is plenty of evidence that the Amazon was largely a geo-engineering project, seems like that one worked out.
The green wall isn’t in the Sahara. It’s across sub-Saharan Africa, trying to keep the Sahara from spreading, not cover it with trees.
Andrew Millison, the creator of the linked YouTube video, has an interesting channel where he essentially showcases applications of / advances in ecological technology (i.e., permaculture.) I take some solace in the fact that his videos get millions of views; suggesting that permaculture / ecological design principles aren't some fringe-y thing any more.