guardian.co.uk: Forests in the desert: the answer to climate change?

[OKIsItJustMe]

http://www.guardian.co.uk/technology/2009/nov/04/forests-desert-answer-climate-change

Forests in the desert: the answer to climate change?

Climate change could be cancelled out in a staggeringly ambitious plan to plant the Sahara desert and Australian outback with trees

David Adam
guardian.co.uk, Wednesday 4 November 2009 18.35 GMT

Some talk of hoisting mirrors into space to reflect sunlight, while others want to cloud the high atmosphere with millions of tonnes of shiny sulphur dust. Now, scientists could have dreamed up the most ambitious geoengineering plan to deal with climate change yet: converting the parched Sahara desert to a lush forest. The scale of the ambition is matched only by the promised rewards – the scientists behind the plan say it could "end global warming".

The scheme has been thought up by Leonard Ornstein, a cell biologist at the Mount Sinai School of Medicine in New York, together with Igor Aleinov and David Rind, climate modellers at Nasa. The trio have outlined their plan in a new paper published in the Journal of Climatic Change, and they modestly conclude it "probably provides the best, near-term route to complete control of greenhouse gas induced global warming".

Under the scheme, planted fields of fast growing trees such as eucalyptus would cover the deserts of the Sahara and Australian outback, watered by seawater treated by a string of coastal desalination plants and channelled through a vast irrigation network. The new blanket of tree cover would bring its own weather system and rainfall, while soaking up carbon dioxide from the world's atmosphere. The team's calculations suggest the forested deserts could draw down around 8bn tonnes of carbon a year, about the same as emitted from fossil fuels and deforestation today. Sounds expensive? The researchers say it could be more economic than planned global investment in carbon capture and storage technology (CCS).

"The costs are enormous but the scale of the problem is enormous," says Ornstein, who is best known for pioneering a cell biology technique called polyacrylamide gel electrophoresis in the 1950s. "It's a serious suggestion in that I believe it is the most promising and practical option in terms of current technology to solve the biggest parts of the problem."

…

[rockymountaindem]

1. That sounds interesting

Of course the political hurdles will probably be insurmountable.

[Ozymanithrax]

2. How do you convince all those countires to change the ecosystem of thsoe regions.

Who pays for it?

[XemaSab]

3. Here's exactly how that scheme is going to go:

Plant eucalyptus. Watch raging bushfire destroy all your trees.

Rinse, repeat.

[OKIsItJustMe]

4. … Rinse, repeat.

OK, so, let’s say that happens, and we have many many square miles of charred eucalyptus trunks.
That standing charcoal represents carbon which is no longer in the air. (No?)

[XemaSab]

5. Eucalyptus burns to the ground.

Sure, you'll have some sequestered carbon in the roots, but you'll also have thousands of acres of nothing, as well as a lot of dead animals, destroyed equipment and wasted money.

Also, where is the energy for desalination going to come from? :shrug:

[OKIsItJustMe]

6. I had the same question regarding the desalination

However it seemed such an obvious question that (although I could not retrieve the original paper) I trusted the authors to have addressed it.

[kristopher]

9. Here you go - it's open access.

http://www.springerlink.com/content/55436u2122u77525/

[OKIsItJustMe]

12. Thanks, and yes (as I suspected) they address it

…

The ‘CO2 footprint cost’ is about equal to the CO2 footprint of the power sources used to desalinate and distribute the irrigation water needed to support it. The energy to pump water from sea level, to an elevation of about 450 m (the average elevation of the Sahara), with 50% hydraulic and electrical efficiency, is 2.46 kWh/m³ . Our above estimate for the power consumed for RO desalination (1.58 kWh/m³ ) plus this additional amount for pumping for distribution totals 4.04 kWh/m³ . The CO2 footprints of coal and natural gas (without Carbon Capture and Sequestration, CCS) and nuclear power are respectively about 0.7, 0.4 and 0.0033 kg CO2 per kilowatt hour (Wikipedia 2009c). Thus, the total mitigation provided by irrigated aff orestation might be diminished by CO2 footprints of about 38% with coal power, 22% with gas and 1.8% with nuclear power.

…

[depakid]

18. Solar thermal and wind

http://www.water-technology.net/projects/perth/

http://anz.theoildrum.com/node/3926

[kristopher]

21. Interesting information, thanks. nt

[malakai2]

7. What's the reflectance of the remaining char?

Also, how much water vapor would a continental eucalyptus forest transpire?

[XemaSab]

8. I'm not the person to ask

I just think that the idea of spending buckets of money and energy on greening the deserts of Africa and Australia is a silly one. :P

[happyslug]

10. The latest effort to divert water to the Qattara Depression and the Dead sea?

One plan that has been kicked around for at least 100 years has been to divert water from the Mediterranean Sea to the Qattara Depression. The difference between the two is only 50 miles and the water drop of about 133 meter (or about 400 feet) (which can be used for electricity generation) is The plan always assumes that most of the water will evaporate away, thus the water is always flowing through the pipes from the Mediterranean Sea. The Qattara Depression is one of the hottest places on earth (if NOT the Hottest, temperatures have been reported as high as

For more on the Qattara Depression:
http://en.wikipedia.org/wiki/Qattara_Depression

A list if such plans:
http://www.unu.edu/unupress/unupbooks/80858e/80858E0a.htm

One of the side affects of these two plans is increased evaporation of water around both the Dead Sea and the Qattara Depression, this will produce increased rain in both area. The down sides are minimal given the lack of any type of life in both areas (Life exists on the margins of both areas but NOT in Qattara Depression itself do to the extreme heat, and while the Dead Sea has some life, its shrinkage do to the various efforts to divert water for agriculture in the area has made it even more salty and hostile to what life exists in the sea).

Another advantage is the dust storms on the middle east, most start in the Sahara and then blow east ward till their hit the Himalayas. Our troops have seen severe cases on this every summer, as does the whole middle east. The increase rain would reduce these storms by a considerable degree.

Now the Atlas Mountains of the Western Sahara are all above sea level so cutting a ditch (or drilling a tunnel) is NOT a variable option for that part of any plan to increase rain in the Sahara (many of the Dust Storms start in the Atlas Mountains so the Dust Storms will continue if the Qattara Depression is filled in by salt water, but it will provide a huge area where additional sand will NOT be picked up thus reducing the size of each storm). In such areas the best choice may be to pump the sea water to some contained area and leave it evaporate. The Sahara is in the transitional area of the plant between the west to east movement of Weather in the Northern Hemisphere AND the almost no movement of weather fronts in the tropics. Thus part of the year it acts like the Tropics and all weather stays local, other parts of the year it act more tempered and you see an West to East flow of weather (This West to East flow provides what little water hits the Sahara and is the source of most of the Water for the Niger River).

List of dry land below sea level:
http://geology.com/below-sea-level/

El Azizia, Libya, which is next to the Qattara Depression has held the record for the highest world temperature ever recorded (this is AIR temperature record, where the thermometer is at least five feet off the ground, to avoid being affected by ground temperatures which can be even higher, AND in the shade, so that direct sunlight does NOT cause the thermometer to record to high a number) at 136 degree Fahrenheit.

List of highest tempertures:
http://hypertextbook.com/facts/2000/MichaelLevin.shtml
http://wmo.asu.edu/world-highest-temperature

[Nederland]

14. There's an odd plug for military benefits in there...

Another advantage is the dust storms on the middle east, most start in the Sahara and then blow east ward till their hit the Himalayas. Our troops have seen severe cases on this every summer, as does the whole middle east. The increase rain would reduce these storms by a considerable degree.

No comment, I just found it odd...

[happyslug]

16. Here is happens, the biggest advocates of Federal Funding for nighttime basketball are the police

The biggest advocates that prisoners should have access to television and the net are the prison guards. Why? For a similar reason as inner city police back evening basketball funding, it is a more cost effective way to do their job.. Prison guards want to minimize tensions in the prisons, if the prisoners have something to do (watch television or go on the net) it minimized tension and thus minimize problems for the guards (and give the guards another privilege they can take away from the prisoners if they cause any problems). Police think the same way, getting inner city youth something to do (i.e. nighttime basketball) gives the teens something to do other then get into fights (and other criminal activities).

Yes, sounds odd, but it is one of the advantages of doing things right.

[excess_3]

11. the people of North Africa won't cooperate

the equipment will be stolen or nationalized

[OKIsItJustMe]

13. Because they really like living in a desert

That's why the African http://www.greenbeltmovement.org/">greenbelt movement has been such an abject failure.

[The2ndWheel]

15. That's not stopping climate change

That's changing the climate.

"complete control of"

Now we're getting somewhere.

[OKIsItJustMe]

17. Applying the brakes in a runaway car is a way of taking control

If you were in a runaway car, what course of action do you think would be best? (Sitting back and “letting Nature take it’s course?”)

[excess_3]

19. water vapor is the biggest greenhouse gas

the TOTAL effect of turning the Sahara
into a watered garden, is not predictable.

climate models can't explain today's climate,
the models certainly can't predict
the future.

[kristopher]

22. If you had cancer...

and you consulted 100 doctors, and 99 of them recommended the same course of treatment, would you reject their advice by saying that their models can't predict the future.

Stop being a jerk.

[excess_3]

23. (suppose) do the doctors exxagerate?

climate models can't explain
today's temperature

unless you 'input' today's temperature
..........................

surprise, these people have their hand out

[kristopher]

24. No they don't

Stop being a jerk.

[The2ndWheel]

20. It would be an option

No crazier than most.

#1, I wouldn't build something that could get out of control to such an extent.

#2, I don't know that we want to put any brakes on anything. We want unlimited energy, so that we can think that we can do whatever we want.