It's not clear to me what the source of water is relative to the size of the forest, because IIUC, in dry regions like Egypt (and California, Israel, etc), unless you use drip-irrigation with targeted crops (which won't grow a forest), agriculture requires a huge amount of water compared to domestic water consumption, so the wastewater stream from the latter intuitively can't be nearly enough to support a forest.
Perhaps they are drip irrigating the entire floor of the artificial forest to minimize evaporative losses? The paper linked in the article [1] doesn't really explain how they are doing this.
EDIT: this article [2] explains the system in a bit more detail. For a sense of the scale of forest vs the wastewater supply, it's a city of 400K people whose wastewater is supporting a .78 square mile "forest". So it's really more like a large park. It's a great demonstration nonetheless, especially if it can be a productive source of food for the city.
Your water needs might drop significantly once the forest is established. Depending on the trees, the established canopy might drop the evaporative losses dramatically.
True, but I think the GP's danans overall point still stands. Household water consumption (and waste) just isn't that much. It takes a lot of households to support a pretty little forest. Maybe a mature canopy increases your efficiency by 50% or more, but you're still working with a pretty small volume of water.
also there is a systemic effect. More forests means more rain.
Under the current models we send most of the rainfall immediately back into rivers + oceans. By creating inland forests we get mini little "oceans" to evaporate and move water for a 2nd rainfall. Each cycle the plants + ground hold onto a little, but mostly it can be evaporated and re-rained again and again. Deserts have the issue that they have little to hold onto the water, and to reevaporate it for subsequent rainfalls.
We have a small 15m by 15m garden here in Kuwait (we have a similar climate to Egypt if not a little more hot). To keep planting all year long, we run a “protect from insects” fine mesh over the entire garden and it feels significantly cooler while still allowing sunlight through. Not scientific enough, but we never thought to check the temperature drop or the sunlight reduction. I may do that this summer just to see how much light is blocked.
Plants don't use most of the sunlight that hits them, and too much will cause heat stress making them less efficient.
The right tarp or net that lets through the most useful wavelengths seems to help more than hurt.
A lot of places are starting to install solar over farm installations on a small scale. Yields are tending up while also generating electricity to run the operation
You still need more than you'd expect. Plants need CO2 to live, and with CO2 at just 0.04% of atmospheric air, you need to let a lot of air (and accompanying water vapour) in and out of your greenhouse to let the plants have the CO2 they need.
Or you burn natural gas to produce CO2 (and some water), but then your carbon sequestration goals go up in smoke...
That is 380 times larger. Unless they are massively underutilizing the current wastewater stream, they need to multiply the irrigation water use efficiency that much, unless they think of forest is going to alter weather systems in such a way that brings rain to the area.
> unless they think of forest is going to alter weather systems in such a way that brings rain to the area.
I am not an expert, but based on books and articles I've read[1], forests tend to do that. I think you don't even need a large patch of forest for it to attract rain, anecdotally.
[1] Get an old copy of The Forest and The Sea by Marston Bates, if you can.
"In 1960, he published the ecological science book The Forest and the Sea, an introduction to how ecosystems work. He compares a rain forest and a tropical sea, their similarities and differences, and through it demonstrates how to understand biological systems."
Something worth reading into are the Nile Water Treaties put into place under British rule of the area, which strongly favour Egypt.
This has come up due to Ethiopia’s Grand Ethiopian Renaissance Dam and the plans being made on how quickly to fill up its reservoir.
I mention this as making forests in the desert is going to end up being a political issue and will likely be used in arguments over water rights in the region, even if its total draw is inconsequential.
The Egyptian argument is likely going to be that the the forests will more than pay for they cost in water due to the lower albedo and induced rainfall, and will eventually become self-suficient as well as provide excess rainfall.
The point is to get rid of the wastewater safe/cheap/efficient rather than grow the forest. Water consumption isn't the concern. They certainly wouldn't be doing drip irrigation with wastewater because wastewater would clog the equipment. Evaporation is expected and desired. Treated human waste is full of pharmaceuticals and phosphates from detergents. It should not be used to grow food unless it is feed for animals. Drainage is a concern on sandy soil. You wouldn't want these sites anywhere near your groundwater supply. You can't dump phosphates and nitrogen in your rivers because the result is algal blooms -> depleted oxygen -> fish kills and really toxic shit like Pfiesteria, which can give you headaches, cognitive problems, and nerve damage just from standing knee deep in the water.
Really, how well the forest grows is beside the point. They're doing this to dispose waste water. If they can make a tree crop to offset costs a bit, then great. The "climate change" angle is lipstick on the pig.
> It should not be used to grow food unless it is feed for animals
If the potential toxins on the crop are the concern, these animals can also then not be for human consumption (directly or indirectly). In a lot of cases they probably can't even produce things for human consumption. There's not a whole lot of use left once you eliminate those use cases.
It depends on what is in your wastewater of course, but most toxin typically concentrates in the leaves rather than the beans/corn. From there, the toxin remaining concentrates mostly in organs which can be discarded, rather than the meat. Each step in the food chain acts as a filter. You do not want to consume the crop directly and have buildup in your organs.
Also, eating food irrigated with waste sludge is a great way to catch e-coli. Treated waste is aerated and anaerobic pathogens like that largely neutralized, but it could still happen. If a hog is sick/dies, it's not as big a deal as a human.
Steps in the food chain are concentrators for toxins, not filters. Discarding organ meat isn't a given, though I suppose throwing away the liver in a lot of cases would be a solution. It seems like it is a risky play for relatively little gain, but I'm not a food regulator.
It would certainly help if you explained why you feel the need to snark about something you can't really know about. That way the comment might serve as a vehicle for interesting conversation, instead of whatever this is.
I can't imagine the phosphates and nitrogen are especially good for the trees, either. TFA says the wastewater is "treated", but it's not specific on just how much they clean it. Presumably more than nothing and less than enough to return it to the municipal water supply.
> Perhaps they are drip irrigating the entire floor of the artificial forest to minimize evaporative losses?
More or less (saw it on german TV a few weeks ago) - here ( https://www.planet-wissen.de/video-aegypten--ein-wald-mitten... ), if you jump to 01:55 you'll see the small pipes that distribute the water, but it's a bit more than just "drip irrigation" (at 02:34 it's visible that it's more than just a few drops).
Less than 500 acres planted using sewege water from cities. The rest (planting millions of acres of forest) is just a wishlist and the article is short on details.
Israel already gets the majority of its water, including for irrigation, from desalination.[1] They achieve this through a combination of conserving and recycling water as well as very targeted irrigation of crops, along with new technology such as the Sorek desal plant. The second generation may be up and running by 2023 [2].
There's an interesting paper [3] about building 40,000 Sorek style plants to sequester excess water in arid areas and avoid problems with sea level rise. Without any savings at scale, this would be around 20 trillion dollars, but that's clearly cheaper than building infrastructure to protect coasts around the world, with the side benefit of creating jobs and food in areas that are in the most need.
I've been working (in the script-writing sense) on a narrative around EarthStations -- molten salt solar towers powering desal plants and green tech manufacturing, surrounded by highly efficient farms, and further out in the ring, forests that eat the desert. Since they are located on coasts, all the infrastructure can be delivered by ships, and all the goods created easily shipped out once they are up and running.
One big technical problem is what to do with the brine -- I'm not sure how much could go into molten salt heat storage. But they could serve as an engine to keep sea levels stable.
This is a longwinded way of saying I think the project in Egypt is a good example of the terraforming we need to be doing instead of dreaming about for a planet like Mars. Even though it is small scale, turning deserts into forests is pretty impressive, and something we need to do learn how to do well to fight climate change.
Karami, A., Golieskardi, A., Keong Choo, C. et al. The presence of microplastics in commercial salts from different countries. Sci Rep 7, 46173 (2017). https://doi.org/10.1038/srep46173
“Our brine is naturally sourced from an ancient, untouched sea called the Iapetus Ocean (predating the Atlantic) trapped below the Appalachian mountains. Our salt is free of contaminants and heavy metals that may be found in other oceans. Gleaned from the earth by an underground brine aquifer, the salt is then processed naturally using the power of the sun and gentle mountain breezes.”
If that isn't a fantastically deceptive piece of marketing then I don't know what is. It writes as if other salt deposits didn't originate in some kind of ancient body of water, and it uses the fact that they're harvesting a brine to imply that the entire bloody ocean is still hiding under the Appalachians, so that by buying their salt you're buying "sea salt" (and all the naturalist voodoo that might entail) but without any of the contaminants of modern oceans. Being low in mercury and whatnot seems like a good thing, and their salt is probably fine, but that marketing is something else.
Isn't seawater like 3 or so percent salt? The amount of salt produced seems like it'd greatly exceed demand. Although maybe this would be a better alternative to salt mining, not sure if that's clean or not.
you'll raise salinity at the dump point to toxic levels and mixing it with water by dumping via ship adds so much complexity and cost it isn't even worth writing about
This is typical in Egypt. There are or have been dozens of “plans” —- most of them half-baked, to develop parts of the desert to reduce densification and centralization in Cairo. When I lived there, the joke was always about how these developers (in cahoots with the military oligarchs) would source the water for these adventures. In practice, it makes no sense. Egypt is approaching critical water vulnerability.
As they try to develop out in to the desert, most of the projects have nothing to say about this critical resource. These developments are therefore totally unsustainable as it requires constantly importing water by truck, building enormous infrastructure from the Nile or desalination facilities plus the transport infrastructure. Even then the cost to actually change the soil composition from desert to anything less arid have absurd water costs, to say nothing of what happens when these theoretical cities have to start providing for demands of the expected hundreds of thousands or millions people.
To make matters worse, development around the city continues, and the prime agricultural lands, where water use is most efficient per calorie grown, has all but disappeared.
In Egypt, like so many other places, but especially in Africa, are increasingly vulnerable to compound effects of man-made and climate change crises. Books have been written on the corruption, but the combined effects with climate are truly frightening to contemplate.
Whatever transpires there after the proverbial well runs dry is going to make the January Revolution look like child’s play.
To be fair, it was a proof of concept to see if it was possible. They did prove that it is possible. The rest of the details probably haven't been sorted out yet for how they plan to scale it. A terraforming project can easily take many decades or even a century to complete. So I think it is encouraging to see them starting and/or attempting this to benefit the generations to come.
checkout the actual forest in Google Maps[1]. If you check the historical imagery in Google Earth Pro, you'll see that sometimes between the end of 2017 and the start of 2018 most of the trees kinda disappeared. I dunno if the forest was cut down or if they just stopped watering it, but its pretty much gone now
In Egypt you already have long stretches of the Indian Ocean coast without mangrove or any other vegetation.
But the problem with mangroves is that these grow more or less in a belt between tropics (~ <= 25degs latitudes), require some rainfall and salinity not exceeding some limits.
I am not aware of any patch of mangroves on the mediterranean coast.
Last but not least, these trees are adopted to tides or estuaries with lower salinity.
You will not reproduce such conditions in an oversized saharan Dead Sea.
Wasn't there even a plan that involved using up the nuclear stockpile to 'dig' a channel and drain the Mediterranean Sea? Of course there might be some opposition to that currently.
Permaculture isn't about "going back in time" its about re-jigging things so that you are not having to put in a tonne of nutrients only to take them out again/let them be blown away.
For example in wide open pastures it can be as "simple" as planting trees for nuts/fruit/lumber widely spaced to cut down on wind. not only that but it cuts down on the need for water because.
This makes up for the reduction in sunlight getting to the grass.
aquaculture is about trade-offs. its about choosing overly high yield now, with ever increasing fertiliser/feed/water inputs (thus higher costs) or reduced yield in the setup phase for much more resilient/comparatively productive and cheaper yields in future.
Yeah, we need sort of drones smart enough so they can pick up the food themself.
With this technology most of the permaculture ideas (protecting plants with other plants) can be replaced with drones.
I have heard a lot of things on this subject.
But I never seen a good article saying it's good. Every article I seen saying it's good only use buzzwords, few numbers, but never tell real life numbers, like how many people worked there, how many they produced, how much they sold it, etc...
Seed Balls Kenya is another reforestation initiative that looks impressive. They recycle charcoal dust to not only form a protective shell around seeds embed within it but also provide necessary nutrition when those are planted in degenerate areas.
I really love this idea. There's a part of me that wants to take this idea of biochar seedballs to support reforestation elsewhere. I live in the PNW, and it would be really interesting to see what it would take to convert lumber scrap/timber waste into biochar/syngas, produce energy from the syngas, and use the biochar to support planting trees (and possibly sequester some of it as well.)
I have seen some of Cody's Lab videos, I'm not really certain it matters whether or not a given resource is desirable for turning into charcoal since, what you are left with at the end of the process is nearly the same either way.
You could think of charcoal as a "substrate" or "substrata" which living organisms can live on and with in.
My process is a simple fire pit, filling over the period of a couple hours from the bottom up (it's fun you can cook on it too) and at then end once the pit full top you douse the entire thing with water. This is the stereotypical dug in, campfire.
During this process material is placed on-top of the burnt material, which slows it's burn (due to lack of oxygen) and the material will transition to charcoal but not further to ash.
There is very little smoke and the coals stay very hot all throughout the process. Due to the lack of oxygen, the syn gases are instead burned fully instead of going into the atmosphere.
Anyways, I can create a 5 gallon bucket of charcoal in a couple hours.
The next step is charging the charcoal, since it has nearly infinite microscopic holes in the material, it acts as a sponge with immense surface area. The charging process fills the holes slightly with goodies for microbiology to utilize, for example nitrogen.
Eventually the charcoal itself starts to be break down (over tens, hundreds, and potentially thousands of years) and serves as a "battery" to fertilize plants and other higher life forms.
I'm super curious about retorts and other systems as well. And how complex it is to capture the syngas for use as a fuel (e.g. could I heat a home with it?)
This says the humidity of the Sahara desert is 25%. I wonder if you could devise some kind of system to collect water from the air? (Taking advantage of the big difference in day and night temperatures)
The Appendix of Dune is what solidified it as one of the best books I've ever read. I remember him going in to detail about how the planet had a type of desert flower that would grow at the bottom of dunes that acted as a catch for the morning dew, concentrating it and preventing it from evaporating away and thereby making pockets of water for the local animals.
Thanks, I was trying to spot it from satellite pictures and it doesn't quite seem to match the ambitious videos that are on the https://www.greatgreenwall.org/ website
I really like the idea though, I hope it goes through
Climate change is making people forget what a forest is. A forest is not a large collection of trees. It is an ecosystem. I know that not all climate-change related programs make this mistake, but overall, the rush to do good things to combat climate change is coming at the expense of people forgetting that if we fail to prevent extinctions today due to natural habitat loss, then no amount of reduced climate change due to non-native species reforestation projects in the future will ever bring them back.
The greatest threat facing the natural world is not climate change, it is habitat loss.
How much water needs to be channeled to simply maintain the current size (demand as the current trees grow)? Is there some metrics of water needed per acre?
Wikipedia indicates that the following are from Australasia and South Asia and therefore are non-native and must have extremely limited conservation value in north Africa:
I am very concerned that climate change is creating a generation that does not understand the value of natural habitat with native plant species. Many people nowadays seems to just care about climate change and not about species conservation.
I agree. Boswellia is native to the region. There is a planting project going on in Yemen for specific species but the fighting has complicated the project. A lot is hitting the species and is likely to increase in demand. NYT piece covers some of the challenges its facing: https://www.nytimes.com/2019/07/05/science/frankincense-tree...
I mean it’s certainly interesting but as others have pointed out the desert is a natural ecosystem and it makes a lot more sense to reforest areas of previous growth than doing this. That’s not really my problem with it though.
Surely from a climate change perspective this is really just introducing a fairly large carbon sink that will eventually release the carbon in short order if the irrigation stops or political will blows in a different direction?
We’re way beyond the point of just planting more trees to combat climate change, although we definitely need to do that too, we need a plan to sequester greenhouse gases permanently, and I’m not sure this does that.
Yeah, and it will be again in 10,000 years, but as per the wiki you site, this is due to Earth's orbital period [1], and it doesn't last very long. And during Green Sahara (if our species is still around to see it) we're likely to see deserts where we now have green.
There's a better way to do it.. Trees can be planted in deserts without irrigation using technology developed by a Dutch company called Groasis [0]. They have also recently come up with a new version of their Waterboxx that can use any kind of wastewater to plant trees, even sea water. [1] Looks like it works via solar condensation which then wicks into the soil so the roots can follow it down to the deeper capillary water ~3 meters below. So no need for drip irrigation.
This new water filter box will come in handy for ongoing restoration projects in the Galapagos Islands etc where fresh water is unavailable. Will make a post for it when more information becomes available.
Not sure if this way is better. After some in-depth searching, I find the key piece in this solution is a "wick", a capillary rising water tube that takes water (of any quality) and feeds it into the ground.
Notice, that it's a playlist with a bunch of these case studies.
The device displayed in the video (the company makes a few different ones) didn't require watering at all, because it collects dew. It's also biodegradable, so there isn't a cleanup cost. They also provide physical protection for the sapplings, which can be important. It seems to add up to very high survival rate in tough environments.
Dew collection at night and massive evaporation of the Sahara during daytime. Not sure if this would be enough to sustain a medium sized tree. Whatever works in Netherlands may not work in Egypt.
The collected water does not evaporate. The linked case studies are in extreme climates, like a 1500-1900 meter altitude mountainside or a desert in Spain, not central Europe.
Rainwater refills it, evaporation blocked via siphon. Most deserts get at least 150-250 liters of water per square meter per year, often much more. [1] The boxes supply enough water for the roots to grow down to the capillary water below.
Wow, thanks for pointing this out. This simple yet very powerful technology will definitely make planting easier. With apparently no need for water supply. This thing amaze me really
You'd have to constantly refill it, which would still require irrigation for transport.
Instead of centralized distillation plus transport, you have distributed mini distillers at point of consumption plus transport. This doesn't seem special, what am I missing?
There is moisture within ~3m in even the driest deserts. The water in the box slowly releases to make a connection with the capillary water deep below for the roots to reach within the first year. It's a planting method, not irrigation. Refills during rains, prevents evaporation via a clever siphon.
Perhaps they are drip irrigating the entire floor of the artificial forest to minimize evaporative losses? The paper linked in the article [1] doesn't really explain how they are doing this.
EDIT: this article [2] explains the system in a bit more detail. For a sense of the scale of forest vs the wastewater supply, it's a city of 400K people whose wastewater is supporting a .78 square mile "forest". So it's really more like a large park. It's a great demonstration nonetheless, especially if it can be a productive source of food for the city.
1. http://www.fao.org/forestry/35800-094f4eedb0c86a4a33be1a3d90...
2. https://www.intelligentliving.co/egyptian-desert-forest-recy...