Greening Earth’s Deserts

[patrick]

A lot of sci fi involves the terraforming of Mars, but here’s an idea… terraforming earth’s deserts. The Sahara is 3.5 million miles² and the Arabian Desert is about another million. Together they’re about the size of the U.S. That’s a lot of unused land that if adapted could feed a whole lot of folks.

 

The problem isn’t necessarily not enough water either. Say even if you could desalinize enough water to adequately irrigate these deserts, evaporation would cause the leaching of salts from lower layers of soil making the top soil too alkali for crops.

 

One idea I had were genetically engineered organisms (fungus or bacteria) that would take nitrogen out of the air and place it in the soil and also take excess salts out of the soil. Another idea was placing towers about 300 ft. tall (think large windmill towers) throughout areas of reclamation and stretching a translucent material between them blocking 10 to 15% of sunlight and evaporation. A side benefit could be the material doesn’t reflect the blocked sunlight but instead turns it into solar power effectively turning these areas into large solar panels.

 

Now granted there are going to be unforeseen consequences. We probably would want to test the technologies on Mars before trying them here. Also politics would probably play a massive role in whether something like this could be tried, but who knows what kind of a future lies ahead. In the end it is just sci fi.

 

With that out there, are there any other ideas on the subject?

[Comic]

Re: Greening Earth’s Deserts

 

It's not my field of expertise, but I believe the Sahara has been growing in area, and is currently ten times the land it covered in Roman times.

 

OTOH, Israel's been successful at greening its own deserts considerably, though not without controversy.

 

Either way, yes, the Sahara has some geopolitical issues that might interfere in your plans.

 

There are smaller, even domestic, deserts to test on.

 

Your solar panel towers could act as condensation collectors, of course.

[Spence]

Re: Greening Earth’s Deserts

 

Egad man!

 

Genetically engineered bacteria! We are already having mass hysteria over making hardier fruits and grains. Imagine the suicidal frenzy of self torture if they think we contaminated an entire desert!

 

And worse than that, we might reduce the population of sand fleas!

 

 

AAAAhhhhhhhhhhrrrrrgrgrgggghhhhhhhhhh! :angst:

 

 

 

 

 

 

 

 

 

[Markdoc]

Re: Greening Earth’s Deserts

 

People have been talking about greening the desert for decades and one large scale terraforming project (flooding the qattara depression, to provide an artifical coastline and a hydropower source) was being seriously developed. As far as I know that project has been shelved, but increasing population pressure and energy demand could easily revive it.

 

Other plans have been gaining speed to use the Sahara as a vast solar energy farm and then wire the energy back over the Med to Europe: the biggest obstacle to that is politics. The local politicians can't promise control over the needed areas and it's a pretty safe bet Europe isn't going to pay for such a huge project, if it's not secure.

 

But as for making it green (as in, useful for agriculture) I dunno. A nitrogen-fixing bacteria (or more likley, fungus) could be made, but it'd take literally centuries (maybe longer) to build up enough biomass to support larger plants and in the meantime, the fungus till has to live on something - nitrogen and sun isn't enough: otherwise the area would already be crawling with plant life. Perhaps if we collected all the vaious biological waste generated by city sewerage sytems and started dumping it there instead of eutrophying our own water?

 

cheers, Mark

[Loxly]

Re: Greening Earth’s Deserts

 

Greattings Earth's Desserts?!?!?!

[Outsider]

Re: Greening Earth’s Deserts

 

Perhaps if we collected all the vaious biological waste generated by city sewerage sytems and started dumping it there instead of eutrophying our own water?

 

It'd give us something to put in all those oil tankers on their way back, instead of running them empty...

 

Or something to use the now idle tankers for, if this scenario takes place after we've stopped using oil so much.

[patrick]

Re: Greening Earth’s Deserts

 

Wow! lots of great ideas!

 

I admit that the only way anyone would be able to pull this off would be if there was some sort of corporate feudal police state involved (i.e. humorless people who shoot those that disagree with them.) Though that may be a not be problem. Not to sound Orwellian, but there a few types of government capable of administering populations of ten billion plus (too many voices in the crowed). The ones that can usually aren’t the ones keen on debate.

 

I didn't know about the Qattara Depression. That's very interesting; though to do it we'd have to come up with a solution for the salinity (I understand that the bottom of the depression is a salt basin). Is there anything naturally that eats salt?

 

Also the idea of recycling waste for biomass is cool. It would do wonders to clean the coastlines and get rid of landfills. I'm picturing some chap from the Middle East going door to door internationally "Excuse me, but would you mind selling me your garbage and poo?"

 

Farming is better work for the soul than oil, though not as profitable.

[Outsider]

Re: Greening Earth’s Deserts

 

The qattara depression project involved cutting a channel from the med to the depression, putting a hydro station in it, then letting the water flow throught the channel. Not only would it generate an immense amount of power from the initial inflow, but it would generate zome more power every year as the water evaporated from the new qattara sea & had to be replaced. As I understand it, the idea wasnt to turn it into a fresh water sea. The new coastline would be mostly for salt water friendly persuits (luxury housing/hotels/resorts, possibly fishing once high salt tolerant fish populations were established, a source of salt water for desalinization, etc) and because a large body of water at that location would act to change climate in the local area. (temperature regulation, change in wind/rain patterns, and the like). Someone (probably Markdoc) posted an article about this in the past, but I didnt see it on a search.

[Markdoc]

Re: Greening Earth’s Deserts

 

Yep. The plan was mostly driven by a need for power (electricity, that is, not the electoral kind). The Aswan high dam is silting up and is, in any case, proving inadequate to Egypt's growing population. At the same, it was hoped that filing the Qattara depression with water would lead to increased evaporation and thus, extra rain in the surrounding area (although the weather geeks say "not so much").

 

cheers, Mark

[McCoy]

Re: Greening Earth’s Deserts

 

It's not my field of expertise' date=' but I believe the Sahara has been growing in area, and is currently ten times the land it covered in Roman times.[/quote']

During Roman times, Egypt was the breadbasket of the Empire. A fleet of ships carried grain accross the Mediterranean for centuries.

 

From what I hear, the problems of greening the Sahara are almost entirely political. Don't have a cite handy, but I have heard that if a patch of land is fenced to prevent overgrazing, plants come back in a couple of years. Not productive agriculture, but some hardy grasses that will keep the sand in place. Sew nitrogen-fixing legumes. they will lie dormant until it rains, then they will sprout, grow for a few weeks, and die. But even if they do not live long enough to reproduce, the roots and the bacteria living in their roots contribute. Then a carefully controlled number of animals can be allowed to graze, maybe two or three months out of three or four years, and drop manure which will help build the soil. Without irrigation and artifical fertalizer, unlikely that it can be productive for anything other than rangeland within less than a century, but can get back to an ecology that is building soil rather than erroding it with nothing more high-tech than a berbed wire fence.

 

Which is the problem.

 

Take any movie about farmers vs. freerangers in the American West, and dub it in Arabic. That's the problem.

[patrick]

Re: Greening Earth’s Deserts

 

During Roman times, Egypt was the breadbasket of the Empire. A fleet of ships carried grain accross the Mediterranean for centuries.

 

From what I hear, the problems of greening the Sahara are almost entirely political. Don't have a cite handy, but I have heard that if a patch of land is fenced to prevent overgrazing, plants come back in a couple of years. Not productive agriculture, but some hardy grasses that will keep the sand in place. Sew nitrogen-fixing legumes. they will lie dormant until it rains, then they will sprout, grow for a few weeks, and die. But even if they do not live long enough to reproduce, the roots and the bacteria living in their roots contribute. Then a carefully controlled number of animals can be allowed to graze, maybe two or three months out of three or four years, and drop manure which will help build the soil. Without irrigation and artifical fertalizer, unlikely that it can be productive for anything other than rangeland within less than a century, but can get back to an ecology that is building soil rather than erroding it with nothing more high-tech than a berbed wire fence.

 

Which is the problem.

 

Take any movie about farmers vs. freerangers in the American West, and dub it in Arabic. That's the problem.

 

Bedouins relocated to terraformed Mars or other fun spots like asteroid mines. Wouldn’t be the first culture destroyed in the name of progress.

 

Sounds interesting, not so much for the Bedouins, but it makes the project more feasible especially if crops are engineered to deal with the poor soil.

 

I had originally thought of a big orbital mirror to reflect away some of the sunlight, but that wouldn't go over too big with Europe.

[McCoy]

Re: Greening Earth’s Deserts

 

Not to sound Orwellian' date=' but there a few types of government capable of administering populations of ten billion plus (too many voices in the crowed). The ones that can usually aren’t the ones keen on debate.[/quote']

Which is an excelent reason to slow down our breeding before we reach ten billion.

[Sundog]

Re: Greening Earth’s Deserts

 

Which is an excelent reason to slow down our breeding before we reach ten billion.

 

Good fraggin' luck. I'm betting on a boom and bust scenario, somewhere around the 20 Billion mark.

 

There's a similar plan to the Qattara Depression one for Australia, involving a cut from the Bight to the Lake Eyre region (which is below sea level, and the location of the inland sea milllions of years ago). The idea is to alter the overall climate for greated rainfall and a natural greening of the land.

[Lawnmower Boy]

Re: Greening Earth’s Deserts

 

I, on the contrary, would be surprised if it hit the currently predicted low range estimate of 10.6 billion. The problem in most of the world already is underpopulation, and it will get much worse, much faster than is currently realised. Imagine what will happen to immigration dependent countries like Canada when China starts aiming for a 1%-of-population-annually like Canada's never-achieved immigration target.

As for the Sahara in particular, a point is being missed. It is _already_ being used for agriculture --as a very low intensity ranch. The limiting resource is water, and by and large we use it well elsewhere, or we'd divert the numerous, gigantic rivers of Africa into Lake Chad and Bob's your uncle.

Such projects, and others, were very much on the table back in the nineteenth century, especially in France, where they got kinda crazy after inventing the first modern demolition explosives. Suez canal, Panama canal, good ideas; diverting the Nile, not so good.

My goodness there's a lot of untapped Pulp Hero adventure seeds out there....

[Lord Fyre]

Re: Greening Earth’s Deserts

 

Another point with this is that deserts are just as much natural ecosystems as Jungles are. And they are just as vital to the Earth's ecology too.

[Cancer]

Re: Greening Earth’s Deserts

 

For the inverse process, greatly accelerated in time, read up on the Aral Sea. Once a big lake, now well on the way to being grossly polluted desert flats.

[Markdoc]

Re: Greening Earth’s Deserts

 

From what I hear' date=' the problems of greening the Sahara are almost entirely political. Don't have a cite handy, but I have heard that if a patch of land is fenced to prevent overgrazing, plants come back in a couple of years. Not productive agriculture, but some hardy grasses that will keep the sand in place. Sew nitrogen-fixing legumes. they will lie dormant until it rains, then they will sprout, grow for a few weeks, and die. But even if they do not live long enough to reproduce, the roots and the bacteria living in their roots contribute. Then a carefully controlled number of animals can be allowed to graze, maybe two or three months out of three or four years, and drop manure which will help build the soil. Without irrigation and artifical fertalizer, unlikely that it can be productive for anything other than rangeland within less than a century, but can get back to an ecology that is building soil rather than erroding it with nothing more high-tech than a berbed wire fence.[/quote']

 

That's certainly part of the problem. A large part, even, but only a part. The trouble is, we have two trends colliding here. The first is simply too many people living on marginal land - that's the part you describe, and I am afraid that Darfur-like situations will continue to multiply. You can't improve a situation like that with a peace-keeping force, because the problem is simply more people than the local resources will support.

 

The second trend is that desert areas (as opposed to the arid ones you describe above) are also spreading, turning arid land into desert and marginal land into arid land. That trend has been ongoing for at least the last hunded years and seems to have more to do with decreased rainfall (or altered rainfall patterns) and higher temperatures. That's makng the effect of overgrazing even worse.

 

cheers, Mark