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Africa is building a Great Green Wall to prevent expansion of the Sahara (youtube.com)
129 points by girafffe_i 7 months ago | hide | past | favorite | 68 comments



I've been following Andrew Millison's work for a while, he's got a lot of really wonderful introductory lessons on permaculture. He's got an online course at the University of Oregon, I'm planning on taking it sometime soon


First saw this a few years ago.

Permaculture - from forest to farm | Clea Chandmal

https://youtu.be/KI3haUOkP-I?si=v_z8xCOKzwLO-May

IMO this is one of the most succint and clear explanations of why permaculture is so important - because it tries to mimic nature, which has had (m|b)illions more years to evolve and create much more intelligent and efficient growth, energy conversion, creation and destruction processes than we stupid and arrogant humans have had in the few tens of thousands of years (at most) that we have been doing agriculture, or should I say, monoculture or even better, stupidiculture.


Looks like Millison is with Oregon State University

https://workspace.oregonstate.edu/osu-permaculture-design



Fascinating video, but still it worries me how sustainable this is. This isn't a "rewilding" process - there is a LOT of manual human labor going into supporting very low yield agriculture.

It seems like this idea relies on a long term low wage workforce willing to live on subsistence agriculture.


> It seems like this idea relies on a long term low wage workforce willing to live on subsistence agriculture.

I think that is already the population. What the attempt seems to be is to create a green belt that prevents further desertification of semi-arable land that they are already subsistence farming on, because if the desert keeps moving, these people will cease to exist.

Captialistically/economically, there is questions as to whether these people should continue to subsistence farm, but if they want to, and it can help keep the desert at bay, then I say more power to them.


These people right now don't have good options. Get them enough food locally and they no longer need to chase all over trying to find enough work to afford food. In turn that means they can send their kids to school and those now educated kids can in turn apply modern things. Some of that is those kids - the ones who don't love farming - leave to better jobs in the city, while others - those who love farming - apply modern farming techniques (which is sustainable, contrary to popular myth) and produce a lot more food while building up the soil even more.

But if you don't have enough food it all fails. History has taught us that in every corner.


Can you expound a bit on sustainability of modern farming techniques?

It has always been my understanding that modern farming is reliant on a large industrial outlay and global trade for things like fertiliser and pesticides. And that it also affects the soil in a way that is hard or impossible to reverse (extraction of certain nutrients that cannot be easily replenished naturally)


This is a very complex question.

Traditional farming is not sustainable because they don't have pesticides and so once in a while your whole crop is destroyed and your whole village starves to death. Some traditional practices slowly destroy the soil over time.

Fertilizers like nitrogen (one of the largest fertilizer uses) are needed for the best yields, but modern farming creates enough as on farm to be sustainable without the addition at lower yield levels.

However when a crop leaves the field it takes away some things like sulfur, potassium, and that needs to be replaced for the next crop. I'm considering this a failure of modern transport to bring those back and not modern farming - but this should feel like a meaningless distinction.

When I say modern farming is sustainable I mean that modern farming is building up soil over the decades. While we need to replace anything actually removed with the crop, the soil is getting better year after year.


I just have strong doubts that people will want to. The video already highlights that the problem in the first place was young people wanting to move to cities or other countries. I would suspect it would revert to the pattern when the UN grant money dries up.


I believe the intent is that the local climate and soil will be sufficiently altered that no laborious long-term upkeep is needed. So its not rewilding per se, but its also not purely agricultural project and parts of green wall afaik are completely non-agricultural. That also highlights the fact that the implementations of green wall projects have been very varied, there is no single formula that is applied everywhere.

But yes, it is ambitious project and there indeed are lot of questions on both short-term feasibility and long-term outlook. As is natural for a project of this kind, the financial aspect is especially messy.

https://www.theguardian.com/environment/2020/sep/07/africa-g...


Senegal has one of the worlds highest fertility rates. They have a surplus of labour, and slowing desertification is a way of improving their ability to both subsist and grow their economy until they can drive wages up.

Note how the video points out how it is causing more people to have reasons to stay in villages that's otherwise get depleted of young people. If that continues, it will have a significant long term benefit for the growth of Senegals economy.


Land improvement is the easiest value creation. Turning unusable desert land into arable land creates huge long lasting benefits. The land has huge value increase. If the people doing the work are deeded the land, they become well off. They are incentivized to maintain the land.


Some of the trenches are there to solely produce biomass. They don’t don’t go into it in the video but it hints to me that they are trying to change the soil.

Now the ground is hard dirt and water runs off. The half moons capture water and makes it possible to grow a tree.

Roots will loosen the soil, and combined with biomass from the bushes in the trenches you can imagine there’s a path towards changing the composition to something more arable in the traditional sense.

To me it sounds like the editable crops are a carrot to keep the locals working toward a much longer term goal.


>It seems like this idea relies on a long term low wage workforce willing to live on subsistence agriculture.

It's a labour intensive, make work program that accepts the reality that there's going to be 100s of millions to billions of Africans who will be stuck in subsistence agriculture for the rest of their lives. You can incrementally improve new workforce over time as society develops, but people who get left behind generally get left behind. Ultimately, their labour is cheap, and need something to do. Maybe you can replace 1000 workers with a piece of specialized heavy machinery that's cheaper, but then you'll have 999 idle hands.


   >> there is a LOT of manual human labor
same reaction. someone bring power shovel diggers.

Also it should be combined with the other Great Green Wall projects, the most successful being "just plant trees" to shade the crops and keep the area cool and humid.


How much do they cost compared to the labour cost that also provides additional employment options and boost the local economy?

"Just plant trees" without doing anything to ensure the trees can survive is not meaningful in all conditions. What they're doing here is effectively "just planting trees" in a way that ensures the area stays moist enough for the trees to survive, and leveraging the same space to grow crops.


There is no particular reason to expect Africa to do better in the near future. Russia and Iran are making large plays and helping dictators kick out the western supported governments (which were already corrupt, but making small strides to less corruption). I see no hope for most of Africa to do better. (note that I said most - There are 54 countries in Africa - several of them are doing very well - I hope this trend continues and spreads)

edit: looking closer, it looks like this might be in one of the few countries that might actually do better. Though that also helps as people who are doing better have time to invest in this. time will tell.


> It seems like this idea relies on a long term low wage workforce willing to live on subsistence agriculture.

There are some who are content with low wages and a simple life of living off the land. Shouldn't technology make this even easier, buy making low cost education available to their kids and making more affordable healthcare possible?


>Fascinating video, but still it worries me how sustainable this is.

What was shown in the video looks like a "mickey mouse" operation, akin to a local tree planting effort to combat climate change. For this to make any difference you can't have people digging "half-moons" at a rate of 1 person/1 half-moon/1 day - that does not scale in any meaningful way. You need to do this kind of project at an industrial scale, with large amounts of heavy machinery and thousands of skilled professional workers - especially since they are discussing creating a "Green Wall" across thousands of kilometers at a width of hundreds of kilometers.


If the Titanic is going down, it's going down, but if rearranging the deck chairs gives you something to do to relieve the anxiety, then I guess you might as well (my life may resemble this particular metaphor).

I read William Langewiesche's travelogue where he crossed the Sahara overland after being a pilot who flew over for a few years. He said that the locals are rather fatalistic about living in such a massive and unforgiving place (people frequently die there); they say that when god decides it's your time, then it's your time. Langewiesche added that if you don't believe in god, then you can replace that with "The Sahara" and it still works quite well.

I cannot imagine that there is much humans can do to hold back the desert. I'm quite sure that the only thing that would matter, a rapid drawdown of carbon emissions, is not possible at this point. I know it sucks, sorry.


Wait is there direct correlation between emissions and the expansion of the Sahara? My understanding was it started forming way before the European Industrial Revolution (any literature on topic would be awesome)


Yeah, the video pretty much says outright that this is a delay tactic to keep the poors from storming into the cities and overwhelming them. Ultimately these people, and even those in the cities, will likely end up as climate refugees and need to relocate elsewhere. Much of the western US is also facing a growing desertification problem and dust and dust storms have been increasing. On the plus side, all the increased atmospheric dust has a cooling effect on the planet.


There is plenty of labor in Africa, that scales very well. Just give the people reason to keep trees and they will plant and water them. There are many local advantages to trees so it isn't hard to get locals to take care of them with small incentives.


> you can't have people digging "half-moons" at a rate of 1 person/1 half-moon/1 day - that does not scale in any meaningful way.

It'll get harder to maintain that pace as heat increases too. There'll be fewer and fewer hours that people can work outside. Rising temperatures will bring more heat-related illnesses and injuries. Considering the amount of ground they want to cover bringing in machinery to speed things up does sound like a good idea.


You don't need to dig them constantly. In a few years your village has enough, and now you just need to maintain them which takes less time and so can be done in the cooler parts of the day. And these green places will be cooler than the desert so even in the heat of the day the whole is cooler.

Of course as the village population grows you send the "young men" out to the edge and have them dig a few more half-moons at a rate of one/day. However they are building next to previous green areas which are already lowering the local temperature, and if sometimes it takes 2 days to build one - who cares, there is no hurry.


If you want to treat this as a nice community project, akin to a community garden - great! Just don't think that this makes ANY difference on the macro scale of solving the encroachment of the Sahara, in the same way that a set of community garden initiatives would not solve, in any way, the problem of feeding a huge urban population. For both those things, you need things done at a massive industrial scale. If you want to feed a largely urbanized population of 350 million, you need industrial-scale agriculture, backed by a massive transport and distribution network. If you want to hold back the Sahara by creating a green wall spanning thousands of kilometres, and hundreds of kilometres deep, that is likewise a massive industrial undertaking.

>Of course as the village population grows you send the "young men" out to the edge and have them dig a few more half-moons at a rate of one/day.

Uh huh - because that's what young men want to do, dig ditches for no wage or subsistence-level wage.

What's going to happen is those who can, will simply leave.


Africa has a large population living on subsistence level wages. The large number of people scales very well right now.

> because that's what young men want to do, dig ditches for no wage or subsistence-level wage.

It is an investment - see that bare desert over there, work off energy by digging it. Then when they "grow up" they discover that bare desert is their land to farm and their time was really a good investment in their future and gives them a good remainder of their life, and their kids a chance for an even better life.

Those who can will leave (unless they love farming), but today the majority don't have any better place to go. Stay in the village at the edge of the desert and dig in these green places means a better life than going to the city and trying to find a jobs (remember these people don't have skills in demand in the city either, other than their ability to dig ditches in the city, at least in the desert they can take ownership of the land they make better and have a farm.)

Ideally in 50 years Africa will improve conditions and industrial scale farming will take over, sending 98% of the people (there decedents) to a city where they work not as basic labor but as skilled labor (doctors, engineers...). However they are not in this position now and this looks like a step on the path to getting there.


Yeah, I suspect that if the UN is actually serious about a Green Wall in the near future, they are engaging in mass industrialized planting. But it's not very expensive to have some marginal community projects here and there


The idea here is to do things in a sustainable way for the local population. What you're describing is the exact opposite.


Or utilize metric tonnes of cheap labor.


#TeamTrees: Africa Edition. Sustainable isn't concerned when emotional, idealistic hype push math, reality, and science aside. Fix the climate first with extreme net negative carbon capture and sequestration. Then we can fix the soil with large herds of herbivores stomping grassland and improving fertility.


They could perhaps send there criminals, prisoners.. this kind of people.. have them man the green wall.


And when they would need more workers... What could possibly go wrong.


Or, you know, pay locals a consistent salary, thus helping the environment and also mitigating extreme poverty (<$1.25 a day) - which is what they are doing.


More importantly, these green spaces are sustainable. So even if you run out of budget in 5 years, the people no longer need you to pay them as they now get everything they need from the work you paid them to do in the past and so they can live without subsidy. Or if you do have budget you can move to some other village and pay them to become sustainable.


Yep!


Very amazing work. Syntropic farming, hadn't heard the term before but glad to do more research into it. Also the half-moons is very smart, very interesting. Interesting they went for half-moons instead of swales like in permaculture design, both aimed to increase water-retention. I guess in such very arid conditions half-moons may work better for water retention


Thanks for sharing. Super interesting video. Never spent a lot of time with it, but I've always been curious how people could rebuild an ecosystem.

I think it was the dune series, that I read a number of years back that touched on this idea a bit in the second or third book? It was not something I ever really thought about before that. It's cool to see a real life example of it.


Universities all over the world are asking that question - and have been for centuries. They have come up with some great answers over time. It takes years for farmers to learn - agriculture (like science) advances on the death of old people who continue their unsustainable practices to the grave - but things are overall much better than the past and getting better.


Yeah there's a lot of that even in the first Dune book. The Fremen's leader is an ecologist and they're explicitly collecting water and preparing to change the entire world to be greener and more livable.


The linked channel has a lot of good videos it, and Mossy Earth is another. They aren't going to make you an expert by any means, but they provide good introductions to various projects that are underway doing ecological restoration. They're nice introductions to the topic.


If you're interested in the trials and tribulations of regreening a desert landscape, I recommend this YouTuber with an ambitious dream:

https://www.youtube.com/@dustupstexas


Very cool to see he's using prickly pear cactus. I'm currently working on a project for regreening arid regions in California using prickly pear on degraded water-restricted former agricultural fields. The prickly pear really is optimally suited for regenerating desert landscapes because they are one of nature's great survivors of extreme conditions. Furthermore, they can produce impressive biomass yields which helps drive significant amounts of carbon underground which helps to structure the soil and feed the soil microbiome / establish mycorrhizal networks for other plants to be subsidized with. Plus all parts of the prickly pear cactus are edible, the fruits are delicious (great at reducing LDL cholesterol too). They are prickly as a mfer tho, my goodness, watch your hands! Plus in the America's they are native and so have natural biological controls in these ecosystems that help prevent unwanted runaway growth. Lots to love about prickly pear!


Very interesting, thanks for sharing.


Also a Geoff Lawton video called something like greening the desert.

A lot of his stuff (including that desert video) can be found here:

https://news.ycombinator.com/item?id=39472378


I hate to be negative, I do, but Shaun Overton is a fool. He's wasting an enormous amount of money, energy, and time to achieve approximately nothing when he could do so much more if he expended those resources on a non-idiotic project. It's his time and money to waste, but it hurts to see it when he could really do a lot of good with it instead. His heart's in the right place.


I'm not familiar enough with the topic to know if you're correct or not, but I don't watch his channel to see his project work out, seeing him learn small things along the way and share that journey but also him connecting with himself and the community around his land in unique ways through his project is intriguing and hopeful. A mad dream pushed forward by a mad man, which may not come to fruition, but it's a whole lot more entertaining than watching people take on small projects that are guaranteed to succeed.



Side effect of this in the long term if it is successful is that there should be fewer hurricanes on the Atlantic.

(Hurricanes are believed to caused by dust blowing off the west coast of the Sahara)


Magical thinking. It ain't gonna happen.



this is interesting! thanks for sharing


I have money please..


Africa is a country


What?


Lol


who is africa

also, this is geoengineering. the same kind the soviets used to do and the chinese do now. it would never be allowed to happen in a western country because someone with deep pockets for a lawsuit would find an endangered species of worm living in a dune or two


3 words.

"Geoff Lawton videos."

You know, that Strine permaculture guy.

Watch at least 15 to 20 of them. Many are short.

Only then talk, people.

https://en.m.wikipedia.org/wiki/Geoff_Lawton

https://youtube.com/@DiscoverPermaculture?si=XVjdWpJk5ZIVTnL...

https://en.m.wikipedia.org/wiki/Strine


I abhor these projects, because they are seasonal- as in dependent on outside funds and thus hyper-fragile. Also usually propped up by colonizers, to detract from some ressource extraction destruction.

Same with wildlife preserves. One bad coup with corrupt politicians, one recession in the west - and its all gone, poached and ruins. Its worthless feel good photo OP, monetary potemkin zoos and forrests, providing the worst kind of hope, the one that has no chance to last in a storm.

What is their solution against nomads and there goat herds which are still a status symbol and in conflict with the farmers of the region? Poisonous plants? Guards? Landmines? How does it prevent building up resentment, when obviously a green landscape is more important to the foreigners, then the starving locals?

How does it solve the hard problem of exponential mankind vs civilizational allmende protection?

How do the plants survive in the climate change storms yet to come?


You didn't watch the video, clearly. They're incredibly simple projects that help permanently convert land from desert to arable. They're not dependent upon the outside for anything except directions, as the only tools needed are what the people already have, a pickaxe and shovel. Once started it can continue on with nothing but locals who want to take more land back from the desert.

Nomads, landmines, buzzwords, you're just looking for edge cases where this fails, and that's not helpful. If it works for 80% of the land they look at, that's mre than good enough.


Don't look at the now, the moment, look at the long run. If they had missionaried for a religion that creates a reverance to natures creation and destruction for self-gain as a colonial, anti-god ideology, that would create longterm prospects for this to survive. If they had planted plants poisonous to goats and sheep, this could have endured longer. If they made this sort of work a yearly festival. That would have done more then a incentive driven strawfire.


Please don't pretend religion has any answers to any real world problems, it just causes problems.


> I abhor these projects, because they are seasonal- as in dependent on outside funds and thus hyper-fragile. Also usually propped up by colonizers, to detract from some ressource extraction destruction.

It depends on the institutional experience of each country. There's a reason this initiative is being done in Senegal instead of neighboring Mali.

WFP funding is fairly consistent and less whimsical ime. It's private donors like the Gates Foundation that tend to be flaky, as they only answer to the whims of the Gates family.

Programs like the WFP, WB, IMF, ADB, USAID, etc need to be auditable as significant amounts of public and private money are invested, leading to demands from multiple donors, compared to family foundations or smaller non-profits.


> How does it prevent building up resentment, when obviously a green landscape is more important to the foreigners, then the starving locals? > How does it solve the hard problem of exponential mankind vs civilizational allmende protection? > How do the plants survive in the climate change storms yet to come?

I plan on using this set of questions next time my girlfriend says we should do something I don't want to do.

> I abhor these projects...

Jeesh.


I dunno, maybe watch the video and get your answers from the people who literally answers them in the video? They're not "planting trees", they're basically just running the normal progression of how sand forests develop at a faster, but still slow enough to take years, rate. Nothing particularly "it'll never work" or "it won't survive" about that.


Its literally in the video, the scenery they drive by - goats and goat deforrested landscape.. but hey, ignore reality


The goats are the stars in this thread




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