5 ms·
How the Great Green Wall is holding back the Sahara desert
- deleted 3y ago[deleted]
- fnordian_slip 3y agoFurther discussion here: https://news.ycombinator.com/item?id=39466851 https://news.ycombinator.com/item?id=39466851
- dang 3y agoThanks! Macroexpanded: Africa is building a Great Green Wall to prevent expansion of the Sahara - https://news.ycombinator.com/item?id=39466851 https://news.ycombinator.com/item?id=39466851 - Feb 2024 (68 comments)
- YossarianFrPrez 3y agoThe Great Green Wall is ambitious in scope, but composed of relatively simple parts: capturing rain-water with berms, planting the right kinds of plants in the right order, and creating a system of ecologically sound incentives for people to participate in the project. It's wonderful to learn about. 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.
- anon291 3y agoIt 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.
- wara23arish 3y agoEveryone is okay with building walls to hold off rising sea waters. Why is this any different?
- debacle 3y agoI 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.
- bcrosby95 3y agoThe Sahara desert is 3.5 million square miles. That will never be re-forested.
- zafka 3y agoNever 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.
- VintageCool 3y agoOkay, 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 https://en.m.wikipedia.org/wiki/Hadley_cell
- 3y ago
- deleted 3y ago[deleted]
- deegles 3y agoReminds me of the proposal to flood the Qattara sea: https://news.ycombinator.com/item?id=35957814 https://news.ycombinator.com/item?id=35957814
- droningparrot 3y agoI 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.
- blagie 3y agoCitation 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
- groby_b 3y agoThis 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 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 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.
- thinkingtoilet 3y agoMy 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?
- micromacrofoot 3y agohard to imagine a downstream effect that's worse than becoming part of the sahara
- anonporridge 3y agoI 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-satellite-reveals-how-much-saharan-dust-feeds-amazons-plants/ https://www.nasa.gov/centers-and-facilities/goddard/nasa-sat... i.e. greening your land might lead to browning mine.
- micromacrofoot 3y agoah 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
- pwthornton 3y agoI 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.
- deleted 3y ago[deleted]
- fnordpiglet 3y ago
- begueradj 3y agoNearly 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 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.
- robbyiq999 3y agoA 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.
- fnordpiglet 3y agoWell, I’m sure they’re great programmers though.
- danlugo92 3y agoTouché
- LastTrain 3y agoJust 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.
- deleted 3y ago[deleted]
- robbyiq999 3y agoThose are invasive weeds. I don’t think they compare well to the native grass and citrus trees they are growing.
- karaterobot 3y agohttps://en.wikipedia.org/wiki/Great_Green_Wall_(Africa)#Risk_of_collapse 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.
- logifail 3y agoQ: 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/ 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-raised-about-a-forest-that-rises-from-the-desert https://e360.yale.edu/features/in-israel-questions-are-raise...