To Save the Planet From Global Warming-Turn the Sahara Green

[MitchJi]

Hi,

http://blogs.discovermagazine.com/8...et-from-global-warming-turn-the-sahara-green/

To Save the Planet From Global Warming, Turn the Sahara Green

A team of researchers has come up with a simple plan to halt global warming: All we need to do is turn both the Sahara and the Australian outback into vast, shady forests.

While that might sound so ambitious as to be absurd, the climate scientists say the project would be no more expensive or technologically challenging than some of the other geoengineering schemes that are currently under discussion. And researcher Leonard Ornstein says it would certainly get results. Ornstein says that if most of the Sahara and Australian outback were planted with fast-growing trees like eucalyptus, the forests could draw down about 8 billion tons of carbon a year–nearly as much as people emit from burning fossil fuels and forests today. As the forests matured, they could continue taking up this much carbon for decades [ScienceNOW Daily News].

The study, published in the journal Climatic Change, proposes huge desalinization plants on the North African and Australian coastlines to convert sea water to fresh water, and a system of aqueducts and pumps to move the water inland. The young forests would be nourished with drip irrigation to prevent water loss through evaporation, and the sandy wastelands would chang into endless groves of heat-tolerant, tropical trees like eucalyptus. All that water engineering would come at a steep price–about $2 trillion per year–but the researchers say that cost isn’t much more than the projected cost of capturing all the carbon dioxide emissions from the world’s power plants and burying them deep underground. They also note that carbon capture and storage technology is still untested on the commercial scale, while everyone already knows that forests work as carbon sponges.

But like other proposed geoengineering schemes, the researchers note that planting these forests might have side effects. The increased moisture could trigger plagues of locusts in Africa, just as the odd wet year does now. It could also dampen existing soils, stopping iron-rich dust from blowing off the Sahara and into the Atlantic Ocean, where it nourishes sea life, the study points out [ScienceNOW Daily News].

ScienceNOW Daily News:

Forest a Desert, Cool the World

By Mason Inman
ScienceNOW Daily News
14 September 2009
For more than a century, a few scientists have occasionally daydreamed of transforming much of the Sahara desert green, with a lush inland sea or vast tracts of farmland. Now researchers say they have actually found a way to make such a scheme work with forests across the desert--and to slow climate change in the process.

The idea is the brainchild of Leonard Ornstein, a cell biologist at the Mount Sinai School of Medicine, who partnered with climate modelers David Rind and Igor Aleinov of NASA's Goddard Institute for Space Studies, all in New York City. They envision desalinating seawater from the neighboring oceans and bringing it inland using aqueducts and pumps. Drip irrigation--plastic tubing to water the trees' roots--would minimize the amount of water lost to evaporation and seepage into sandy soils, allowing trees to prosper in areas that are parched today.

According to climate simulations to be published next month in the journal Climatic Change, the forests would cool the Sahara by up to 8°C in some areas. "Eucalyptus grandis and a large number of other tropical tree species are heat-tolerant, so long as they have an ample supply of water in the root zone," Ornstein says. The tree cover would also bring more rain--about 700 to 1200 millimeters per year--and clouds, which help reflect the sun's rays back into space. The scheme could also work for the arid Australian outback, the team reports.

Ornstein says that if most of the Sahara and Australian outback were planted with fast-growing trees like eucalyptus, the forests could draw down about 8 billion tons of carbon a year--nearly as much as people emit from burning fossil fuels and forests today. As the forests matured, they could continue taking up this much carbon for decades.

The project wouldn't be cheap. Adding up the costs for building, running, and maintaining reverse-osmosis plants for desalination and the irrigation equipment, the researchers put the price tag at some $2 trillion per year. The price would be roughly comparable to that of capturing carbon dioxide at power plants and storing it underground, which would eventually cost about $200 per ton of carbon, according to a recent study from Harvard University's Belfer Center for Science and International Affairs, compared with about $400 per ton of carbon for the forests. "Any solution to climate change has to be a multitrillion-dollar project," Ornstein says. "The issue is what the payback is." In several decades, the forests could be sustainably harvested as a source of fuel for wood-burning power plants, making them a nearly carbon-neutral energy source, Ornstein argues.

Planting these forests might have side effects. The increased moisture could trigger plagues of locusts in Africa, just as the odd wet year does now. It could also dampen existing soils, stopping iron-rich dust from blowing off the Sahara and into the Atlantic Ocean, where it nourishes sea life, the study points out.

Despite the drawbacks, the proposal "is incredibly important and definitely worth taking seriously and looking into further," says atmospheric scientist Richard Anthes, president of the University Corporation for Atmospheric Research in Boulder, Colorado. "The benefits could be enormous and go well beyond carbon sequestration," making vast areas far more livable and productive. The key issue is whether desalinating enough seawater would be affordable, Anthes adds. "This paper suggests that it is."

 

[MitchJi]

Hi,

Original Study is here:
http://www.springerlink.com/content/55436u2122u77525/fulltext.pdf

Abstract Each year, irrigated Saharan- and Australian-desert forests could sequester
amounts of atmospheric CO2 at least equal to that from burning fossil fuels.
Without any rain, to capture CO2 produced from gasoline requires adding about $1
to the per-gallon pump-price to cover irrigation costs, using reverse osmosis (RO),
desalinated, sea water. Such mature technology is economically competitive with the
currently favored, untested, power-plant Carbon Capture (and deep underground, or
under-ocean) Sequestration (CCS). Afforestation sequesters CO2, mostly as easily

 

[johnrobholmes]

I don't know if I am in the minority here, but I don't believe that our fossil fuel usage has/will impact the planet climate enough to worry about. The earth has so many climate changes already, and we have been on an upswing for the past few hundred years.


I do think that renewable resources are important however. The Sun is where it all comes from, we should just try to tap it directly.

 

[julesa]

I don't know if I am in the minority here, but I don't believe that our fossil fuel usage has/will impact the planet climate enough to worry about. The earth has so many climate changes already, and we have been on an upswing for the past few hundred years.

I do think that renewable resources are important however. The Sun is where it all comes from, we should just try to tap it directly.

Oh $#!@+, PLEASE don't turn this into another thread on whether human carbon emissions are changing the climate.

 

[Cackalacka]

My main question; $2 trillion aside, is irrigation.

My area is coming out of a severe drought; over the past several summers, I've used rain barrels to collect water that I use for watering a modest-sized garden. Despite having a small house with a small roof, it has worked exceptionally well. I don't have much of a green thumb, but I think the plants knew I busted my ass for em, and have rewarded me with plenty of squash, heirlooms, habeneros, etc.

I bring this personal anecdote as relevent: my house is down-hill from the open space in my back-yard (and location of most of my plants.) As we all know, water flows the other way. I've gotten around this via pumping water from my barrels into a small cistern I built back there, which slowly flows water into soaker hoses (I really want drip hoses, but I have no freaking idea where to find them.) To pump the water, I take a small pump and draw the water from each of the barrels. This takes energy.

But take my analogy & replace my back-yard garden with these Eucolyptus trees in the Sahara. Replace my sistern with a reservoir (or aquifer?) in the middle of a desert that will reach 120+ degrees Farhenheit. Replace my 0.1 hp electric pump with a very large piece of equipment (and probably quite a few large pieces.)

And replace my roof with a source that folks are already scrambling for (Sahel or Nile.) That's the kicker. Darfoor, Chad, this is what happens when the well runs dry.

Cairo is one of the largest cities on Earth. This isn't the Colorado river where you can tell the folks to swallow their spit, like the Californians have told our southern neighbors.

So you've got $2 trillion in material cost, but then you expend a tremendous amount of energy moving water that isn't there (or distilling it, burning even more energy.) Or you tap into someone else's straw in a very precarious locale.

Or you can get folks to understand that maybe Jimmy Carter was right, turn off their lights, and make some realistic rational choices based on science (and not some Michael Crighton Exxon-Mobile bullshit.)

OK, so maybe we're going to have to plant some Euchalyptus trees...

 

[EMF]

"To Save the Planet From Global Warming-Turn the Sahara Green"

What could go wrong???....

/S

 

[StudEbiker]

"To Save the Planet From Global Warming-Turn the Sahara Green"

What could go wrong???....

/S

ROFLMAO!!!! Someone should tell these people the earth is actually cooling.....somebody stop them before they cause another ice age. Bottom line is the Earth has been cooler before the ICE and the Earth has been hotter before the ICE. Who in the hell do these "experts" think they are to decide that the Earth is now at the perfect temperature and this is the temperature we need to maintain forever. Oh God how vain we humans can be.

 

[julesa]

Sigh. In ancient history sea level rise wasn't a big deal, because we didn't have centuries of infrastructure built right at sea level.

 

[dogman dan]

Ever look at the energy cost of desalination? Takes a lot of fossil fuel. And one small suggestion, Lets do New Mexico first, then the sahara. :lol:

 

[John in CR]

The Chinese can't prevent their desert from taking over previously useful land, and people really think they can irrigate the Sahara...hahahahah!

It's sad really that people some actually believe this nonsense. Next thing you know they'll want to put snow making machines in Greenland and Antarctica. Oh no, now I've given someone another idea for a greenscam.

John

 

[swbluto]

The Chinese can't prevent their desert from taking over previously useful land, and people really think they can irrigate the Sahara...hahahahah!

I think human civilization has quite a bit of experience with irrigation to know what's possible. The accuracy in cost estimation is another story for something as unprecedentedly large as the Sahara.

 

[317537]

Thats right!

Turn us Aussies into ecco farmers because the oil addicted counties need their fix.



I hope the people converting 02 into CO2 are going to foot the bill.

:lol:

 

[317537]

We are already at it guys.

You can donate to these very epic efforts undertaken by Australians.


http://www.greeningaustralia.org.au/

 

[StudEbiker]

Sigh. In ancient history sea level rise wasn't a big deal, because we didn't have centuries of infrastructure built right at sea level.

The Earth really doesn't care where we've built our crap. Centuries are but the blink of an eye. The mere idea that we can stop the Earth from warming or cooling, or for that matter stopping the Earth from claiming what is hers is as vain as vain can be. Arizona was once under the ocean. Washington and Oregon were once part of the Asian continent and you think we are going to keep our precious beach houses safe?? :lol: :lol: :lol: :lol: :lol:

 

[spinningmagnets]

In ancient times, major cities were built on a large fresh-water river. The location was near where large ocean-going vessels could reach, cargo was unloaded and put onto roads, or smaller boats that could go up-river where its shallower.

Rome was originally built in such a place, but then a volcano/earthquake-inspired tidal wave destroyed the entire city. The survivors re-built the city 7 miles farther up the Tiber river at its present location.

What do we do? When New Orleans sinks, we build levees so that houses are 15 feet below sea level...what could possibly go wrong?

In St George Utah, the weather is the same as Las Vegas (brutally hot summers). Before electricity, houses were built with a basement (10-feet down the ground is cool, even in summer) and the houses had wide eaves that shaded the walls and windows of the entire house (no grass lawns either, it is a desert), but now?...

During the housing boom of 2004/05 developers wanted to minimize costs and maximize interior square footage. So, no eaves (at all) and no digging basements because rooms are cheaper above ground. Newly-arrived retirees can barely hear each other over the constant hum of enormous air-conditioning units. And there's a fight over an expensive project to bring more water from far away to keep the golf courses green...

 

[julesa]

Sigh. In ancient history sea level rise wasn't a big deal, because we didn't have centuries of infrastructure built right at sea level.

The Earth really doesn't care where we've built our crap. Centuries are but the blink of an eye. The mere idea that we can stop the Earth from warming or cooling, or for that matter stopping the Earth from claiming what is hers is as vain as vain can be. Arizona was once under the ocean. Washington and Oregon were once part of the Asian continent and you think we are going to keep our precious beach houses safe?? :lol: :lol: :lol: :lol: :lol:

I don't care much about beach houses, but I bet the people who live in them do. It's a matter of time. You're talking about changes that happen over millions of years. I'm talking about what's happened in the past hundred years and what will happen in the next hundred years. Laugh all you want, but I think it's a shame so much human effort will be destroyed. All that being said, irrigating the Sahara sounds pretty far-fetched too.

 

[thomas]

Why turn it green when you can build huge sun powered steam turbines to provide electricity for a large part of the world?

http://www.desertec.org/en/

 

[EMF]

[youtube]TxCQHn-w0Bw[/youtube]

 

[MitchJi]

Hi DM,

Ever look at the energy cost of desalination? Takes a lot of fossil fuel.

The desalination and pumping could be done with energy generated with Solar Thermal. No shortage of Sun in either the Sahara or Australia and no shortage of water in the oceans. So its definitely possible.

It might be good (aside from CO2 issues) to make some significant portions of those deserts agriculturally productive and use a significant portion of the Sahara for Solar Thermal electricity generation.

 

[liveforphysics]

Rain forest, and wetland areas are the largest greenhouse gas producers on the planet.

For atmospheric impact,
1 Methane = 21 C02.

Rainforests and wetlands are at equilibrium with rate of growth vs rate of decay (duh). However, the rotting biomass on the forest floor that was created by drawing CO2 from the atmosphere evolves ~1/6th of that carbon sinked biomass into Methane gas, which is 21times more damaging than the CO2 it absorbed to begin with. Wetlands function in a similar manor.



All of human carbon release is small vs rainforest and wetlands.

But, arid forests (like proposed) are fine carbon sinks. Marine algae's are an even more amazing carbon sink, and you don't have to water them But they do need to be harvested, or they quickly also reach growth/decay equilibrium, and become part of the problem, like wetlands.


Turning desert into arid forest seems like a winner to me if it can be done in a passive way. Active teraforming is so energy/resource intensive.

Best Wishes,
-Luke

 

[liveforphysics]

Another fun bit of trivia. The total greenhouse gas influence of 532million cars in the world is only 89% of the impact of the 1.5 billion cattle in the world. And either of these is minor when compared with the rainforest/wetlands methane.


Best Wishes,
-Luke

 

[dogman dan]

It allways amuses me too, to see how people all worried about global warming allways want to have a compost pile. Let's take sequestered co2 and make some methane with it! I see those people riding bikes too, for a half hours recreation, but not to take the place of the car.

I'm pretty pessimistic about GW though, human nature is to keep screwing up the enviroment till somebody with a gun, or economic reasons stop it. Around here, the illegal household trash dumping issue just won't go away. Why drive the extra 3 miles to the trash collection dump? It's cultural, and related to how things are still done in Mexico. You'd think a mere littering problem would be solved by now, but nope. The trash will have magazines with the address labels removed, so you know they planned it, and know better.

I agree, the Sahara would be a great place to do solar thermal, like the huge greenhouse attached to a chimney, and the power could be used to desalinate water to grow tomatoes in the greenhouses. The tomatoes would only cost about $20 each. If desalinating water to grow a crop would work economically we'd be doing it here. About half of NM is a basin with no outlet to the sea, similar to the one at Salt Lake City, bonnevile etc. A few billion years worth of salty water is undeground there. Solar power desalinating water for humans to drink is still a good idea, It's just that only people sitting on lots of oil or other money can afford desalination. For irrigation, you need really cheap water.

For fighting GW, I think step one is to go to biofuel, such as algea to stop using fossil fuel in cars, and houses. Solar and wind too of course. The the fossil fuel we do burn like coal has to get some kind of CO2 scrubber on the stack. Once we get emisions of CO2 closer to neutral, then we have to attack stuff like the cow farts. But like I said, I'm pessimistic, more likey war, either shooting or merely economic will be seen as more important.

 

[liveforphysics]

India has roughly ~350 million cows, and they aren't used for food. The India cows standing around equals the green house gas polution of about 1/4th of all the vehicles in the USA. I'm not saying India is the problem, just interesting food for thought.

The greatest and most feasable impact humans could make on reducing greenhouse gas production on the planet would be to slash and burn the worlds rainforests, and then divert water and/or drain wetlands.

Burning the rainforest has the initial impact of a release of bio-sinked carbon, but this release is offset in roughly 3 years by the huge reduction in methane production. By 10-15 years after burning the rain forests (depending on high/low biomass estimations), it would offset the production of greenhouse gasses by a greater extent than all of the fossil fuel burning that has been done in the history of human kind.


However, I happen to really like the rainforest, and would rather just enjoy the natural slow climate change process in which ever direction it wants to go (we are currently on a downward temp trend).

Best Wishes,
-Luke

 

[ElectricEd]

Earlier this year a friend said to me "with the floods in far North Queensland causing the flooding of the inland and filling up Lake Eyre, I bet we have a wet Spring in Victoria this year."
Guess what? For September so far I have had 205.7mm measured with my rain gauge which is nearly three times greater than anything in the last 5 years.
All of the evaporation from the Lake Eyre basin has to go somewhere. The low pressure zones rotate clockwise down here in Oz, so any moisture picked up in the Northen part of the low gets carried down to the South East dumping rain on Victoria with warm blustery storms and a bit of thunder and lightning.

Here in Victoria our dumb, know nothing, good for nothing Premier and his water minister are building a desal plant that is going to need another WET LIGNITE COAL fired power station just to run it.
So, a proposal. (Putting aside the very big ecological issues for a moment). Lake Eyre is a salt basin that is 49 ft below sea level. It covers about 1/6 of the continent of Australia, how much of this is below sea level must be an enormous area.
Cut an aqueduct from the Spencer Gulf in South Australia and flood the basin with sea water. As Lake Eyre is a salt lake, sea water would actually dilute the salt content somewhat.
If my friend's theory is true, then this would ensure an increased rainfall over the South Eastern states where much of the Australian food bowl is located.
For irrigating the the surrounding land for trees, a system of desalinating aqueducts could be used...
A cross section of the aqueduct.
I apologise for not knowing who the inventor is and being able to credit him/her. The aqueduct works by running saltwater along the middle, the heat from the sun causes the water to evaporate which condenses on the film and runs down into gutters on the side which carry the fresh water to discharge points.
As Lake Eyre is below sea level, no pumping would be required for the main salt water supply, only for the fresh water take-off pumps which would be run by solar electricity. The economics might put the kibosh onto it regarding kilometres of channel/litres of fresh water, but I reckon the capital cost must be a lot less than a conventional desal plant and associated power station.

Now back to the ecological issues:
Unique flora and fauna around the basin.
The Great Artesian aquifer underneath.
Mound springs developed over millions of years.
Migratory birds.

Miscellaneous:
Enormous geothermal potential 4-5Km below.
Gas and mineral deposits.

Very few things are simple "no-brainers" but if the environmental and miscellaneous problems could be catered for (and I can't say how), this must come close.

Comments anyone?

 

[spinningmagnets]

This is such a large and complex subject, but since you mentioned India, I'd like to add something about unpredictable human reactions. India is often discussed as a world "community" failure to help the starving poor. The 350-M cows mentioned wander farms and eat as much as they want. Due to the local religion, they are "sacred".

If not for wandering cows eating as much as they like, the farms of India would be a net exporter of crops. How about family planning and sterilization?

There is an enormous underclass of families in India that are born, live, and die in the gutter. Either starving to death from malnutrition, or constantly teetering on the brink. Many children die. At one point the UN funded (read: USA dollars) free voluntary vasectomy sterilizations and tried to encourage a "one child" policy. Hoped to reduce starvation and poverty, and increase child survival.

Didn't work...nobody wanted it. why? Polls showed the poor all felt the same. In order to have one or two children to survive into adulthood so that there would be someone to care for them when they are old, they wanted to have many children. They believe in re-incarnation, and a childs suffering and death "in this life" is simply fate.

Cows burp methane a LOT. They eat grass and grains which go into their first stomach. It is half chewed, and enzymes help break down the food further. Later they regurgitate their "cud", and chew on it some more, then swallow it into the second part. Decaying warm wet grass makes a lot of burping methane....350-Million cows.

T-shirt for a Hindu EMO rebellious teenager (black fingernails and a nose ring, working at a vegetarian pizza shop): "I didn't believe in reincarnation in my previous life,...and I don't believe in it now"!