What Do We Think About Climate Change

Feature: On stupid ideas to "cool the planet"

November, 2009

Sometimes people get so excited about the idea of enhanced greenhouse they rush to propose "cures". Have a look at this one:

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



One day, this could all be trees … a recent scientific paper claims that turning deserts into forests is the best way forward. Photograph: Guido Cozzi/Corbis

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."

The scheme could cost $1.9tn a year, he says. "When that's compared to figures like estimates of $800bn per year for CCS, our plan looks like a loser. But CCS can address only about 20% of the problem at the $800bn price. Mine addresses the whole thing. And CCS would involve a network of dangerous high-pressure pipelines coursing through the most developed neighbourhoods of our civilisations, compared to relatively benign water aqueducts in what are presently virtually uninhabited deserts." (David Adam, The Guardian, Nov. 4, 2009)

The above is based on this Irrigated afforestation of the Sahara and Australian Outback to end global warming in Climatic Change -- it's open access so you can download the .pdf and view the supplemental movies.

Sounds great, doesn't it? Most everyone loves trees and who wouldn't like to see the deserts bloom again? But could it work? Or, more importantly, would it work as advertised?

In short, no. Their stated calculation is that "the forested deserts could draw down around 8bn tonnes of carbon a year, about the same as emitted from fossil fuels and deforestation today", so it couldn't reduce enhanced greenhouse effect, only slow its growth (just ignore all the energy requirement for that amount of desalination, earthworks and construction...).

Worse, it's inappropriately based on regional simulations performed with GISS ModelE, with its listed global shortcomings:

Principal Model Deficiencies

ModelE [2006] compares the atmospheric model climatology with observations. Model shortcomings include ~25% regional deficiency of summer stratus cloud cover off the west coast of the continents with resulting excessive absorption of solar radiation by as much as 50 W/m2, deficiency in absorbed solar radiation and net radiation over other tropical regions by typically 20 W/m2, sea level pressure too high by 4-8 hPa in the winter in the Arctic and 2-4 hPa too low in all seasons in the tropics, ~20% deficiency of rainfall over the Amazon basin, ~25% deficiency in summer cloud cover in the western United States and central Asia with a corresponding ~5°C excessive summer warmth in these regions. In addition to the inaccuracies in the simulated climatology, another shortcoming of the atmospheric model for climate change studies is the absence of a gravity wave representation, as noted above, which may affect the nature of interactions between the troposphere and stratosphere. The stratospheric variability is less than observed, as shown by analysis of the present 20-layer 4°x5° atmospheric model by J. Perlwitz [personal communication]. In a 50-year control run Perlwitz finds that the interannual variability of seasonal mean temperature in the stratosphere maximizes in the region of the subpolar jet streams at realistic values, but the model produces only six sudden stratospheric warmings (SSWs) in 50 years, compared with about one every two years in the real world. ... Climate simulations for 1880-2003 with GISS modelE -- Hansen et al. 2007, in press. (that link is stale but the deficiencies remain current from the most recent listing viewed)

As yet there is exactly zero evidence running regional simulations in GCMs has any prognostic value whatsoever. And yes, I'm cheating to some extent since models are renowned for being unable to accurately reproduce cloud formation and precipitation, being less accurate than a table of random numbers at regional scales, so I knew before opening the document they had next to no chance of getting the numbers close to real world values.

You've seen Earth's energy budget before, just for a change we've given you a more colorful version of Kiehl and Trenberth, just remember these numbers are averaged across all latitudes:

Radiation budget from Kiele and Trenberth

Very pretty, you say, but what's that got to do with a scheme to forest the Sahara? A fair bit really, let's look at a couple more pretty pictures before we break down a few numbers. Firstly, let's consider albedo -- the amount of incoming solar shortwave radiation (ISR) reflected back to space:

NASA images courtesy Takmeng Wong and the CERES Science Team at NASA Langley Research Center

Observant readers will immediately note that the bright Sahara, Sahel and Saudi Arabian Peninsula reflect a staggering amount of solar radiation back to space. Oceans and forested areas, not so much and in fact these regions have very low albedo compared with deserts and particularly thick, low cloud and ice and snow fields in summer season.

Another point to note is the usual Mercator Projection trap for the unwary embedded in the above projections: distortion of scale. Polar regions and Greenland do not really reflect the vast amount of ISR the casual viewer could expect from the above graphics, more realistic area representation is found in Sinusoidal:

or Mollweide projections:

Relative areas compared - Equatorial aspect
Mercator Greenland
Africa
Mollweide
and Earth Greenland
Africa

You can read all about the wonderful world of Cartographical Map Projections on Carlos A. Furuti's site. The table at right comes from there and gives you an idea of scale distortion involved. Rather than being larger than the Sahara Greenland is in fact smaller than the Saudi Peninsula.

OK, that's one small problem because, referring to Kiehl and Trenberth above, Earth's average surface albedo is listed as a mere 30 Watts per meter squared (W/m2) or about 8.8%, which is fair enough because seven-tenths of the planet's surface is water and that has very low albedo. The Sahara though is one bright desert, easily topping the average 15-40% albedo for arid regions while evergreen forests range from a lowly 5-15%. Even if the irrigated forests encouraged 40% cloud cover (the global average) and these clouds were perfect 100% reflectors there still couldn't be a decrease in absorbed ISR. I average it like this:

700 W/m2 * 0.4 (near-perfect reflection from 40% cloud) = 280 W/m2 averaged over the whole area +
300 W/m2 * 0.6 (unclouded balance of region) * 0.3 (approximate ratio of forest:desert albedo) = 54 for a
net average of 334 W/m2. No improvement there over the native desert state indicated by CERES.

Just to run the global average numbers so there's no doubt, clouds, dust and other aerosols and atmospheric scattering combined account for about 77 W/m2 or 22.5% ISR while the CERES graphics show the Sahara as reflecting roughly 5 times that. Moreover, irrigation and forestation will inevitably reduce the dust sourced from the Sahara and Central Australia that is part of the listed atmospheric albedo and which supplies iron to the iron-starved oceans, feeding the algal blooms that draw down atmospheric carbon dioxide and providing the basis for the oceanic food chain.

No cooling there for their trifling annual price tag of $1,900,000,000,000 (1.9 trillion dollars) and some potential downsides beginning to appear (just imagine if someone wanted to deliberately discolor the Arctic summer sea ice and Greenland, which together amount to similar albedo as the Sahara).

Update: my use of K&T 1997 for energy balance calculations may be more problematic than first realized. I see no reason to doubt this communication in one of the released CRU e-mails:

... http://junkscience.com/FOIA/mail/1255523796.txt

On Oct 14, 2009, at 10:17 AM, Kevin Trenberth wrote:

Hi Tom
How come you do not agree with a statement that says we are no where close to knowing where energy is going or whether clouds are changing to make the planet brighter. We are not close to balancing the energy budget. The fact that we can not account for what is happening in the climate system makes any consideration of geoengineering quite hopeless as we will never be able to tell if it is successful or not! It is a travesty!
Kevin [em added]

That's this Kevin Trenberth: http://www.cgd.ucar.edu/cas/trenbert.html of Kiehl & Trenberth (1997) energy balance fame, with subsequent revisions.

Obviously that could seriously upset my calculations but apart from understating the potential percentage increase in local greenhouse effect there's no apparent problem (it could easily increase local GHE by 150% by moistening the atmosphere, although the IPCC's +3 °C for 2xCO2 still appears overstatement by a factor of 4). The CERES data should not be affected by Trenberth's admission that we can not model energy balance since that is empirical data, not modeled make-believe. Either way holding atmospheric carbon dioxide steady, as they claim their proposal could do, and increasing the proportion of wet tropical atmosphere is no way to reduce net greenhouse effect. :End update

What's that? You like forests better than deserts and think addressing global warming is urgent? Well we think vegetated regions are nicer too but hang on, we haven't finished the temperature calculations from this little fantasy just yet. They write blithely of towering 100m Eucalyptus grandis -- in sand dune country?

Sorry guys, simply not compatible with the relatively shallow soil moistening proposed, these tall (and thirsty) trees have a deep reach. Below is more what you could achieve:

Forest savanna as could be established in the Sahara.

One thing about desert atmospheres that most people can agree on is that they tend to be rather dry and short on cloud cover, which is why they lack much of the greenhouse effect responsible for reducing nocturnal cooling and keeping minimum temperatures from plunging overnight in moister regions. It is theoretically possible for carbon dioxide (CO2) to capture almost 40% of outgoing longwave radiation (OLR) although this is based on a bit of a trick -- it relies on a theoretical nitrogen (N2), oxygen (O2) and carbon dioxide (CO2) atmosphere and a total absence of all other greenhouse gases. In the real world CO2 is thought to account for about 5% of tropospheric greenhouse effect while water vapor and clouds account for 95% (S.M. Freidenreich and V. Ramaswamy, “Solar Radiation Absorption by Carbon Dioxide, Overlap with Water, and a Parameterization for General Circulation Models,” Journal of Geophysical Research 98 (1993):7255-7264.).

In the Sahara then we have greenhouse effect from CO2 plus a lower than global average contribution from water vapor and clouds, all delivering relatively low net greenhouse effect and these guys want to irrigate and forest areas totaling roughly 10 million kilometers squared (10,000,000 Km2), moistening the desert air with increased evapotranspiration and consequently significantly increasing regional greenhouse effect.

Referring back to the energy budget above and using global average figures, CO2 probably delivers at minimum 324 x 0.05 = 16.2 W/m2 downwelling longwave radiation (DLR) and could possibly manage 40% or 324 x 0.4 = 129.6 W/m2 in a totally dry atmosphere. Theoretically OLR capture by water in its various forms could be increased in the desert from its current relatively low level to 95% or 307.8 W/m2, which means reducing some of CO2's listed effect but still delivers a 60% net increase in total greenhouse effect. Hot desert air can have high absolute humidity (and does by the Mediterranean Coast, for example) but across the regions targeted for forestation this is more the exception than the rule.

Exactly how much greenhouse increase is involved? That's difficult to say since basic data is missing but given the increase in potential cloud cover and moisture availability it could be 60% or 205 W/m2 (it would be silly to assume less than 40% or about 130 W/m2). Over approximately 10 million Km2 that equates to about 4 W/m2 over the whole planet. In turn that is the same as the IPCC's guesstimated increased forcing for a doubling of atmospheric carbon dioxide, which will allegedly yield +3 °C global warming, just as could be expected from this über expensive cooling scheme (the lower bound estimate of 40% would equate to 1.8 °C global warming). Not exactly as advertised, is it?

It's all very well for us to hypothesize and guesstimate on this but is there any support for irrigation-driven warming in the literature?

Yes, in fact there is. John Christy and Bill Norris have published on the topic. Here's a link to the UAH press release: "Irrigation most likely to blame for Central California warming" and you'll find a .pdf of their paper here.

Irrigating deserts might be desirable for any number of reasons but cooling the planet should not be one of them. And this doesn't even consider the energy and engineering costs of their little scheme, which they cost at about a buck a gallon of gas -- based on information from Wikipedia, no less...

If enhanced greenhouse is really a problem (and we see no evidence that it might be) then increasing net global greenhouse effect and warming the planet by moistening the atmosphere in the dry regions of the highly irradiated 0-30 degree latitude band is no way to cool the world, is it? In fact reducing something by making it larger is about the stupidest method proposed yet and they only want to spend 1.9 trillion dollars every year for the foreseeable future to do so.

Environmental remediation is pretty cool but planetary air conditioning is not the reason to do it. "Cooling" the planet by heating it is a really stupid idea.

PlayStation® climatology... Sheesh!

http://junkscience.com/Greenhouse/stupid.html

 

junk science eh

aptly named

also a really good example of agnotology

 

So I gather that you support the spending of trillions to plant the Sahara desert in order to achieve reduced albedo right?

Boston, do you get paid to talk through your hat, or do you do it just for sport?

 

well you got the article from a site called Junk Science which is a denier media outlet designed to proliferate agnitology, so immediately there arise questions as to the accuracy of the reporting ( same article also suggests giant mirrors in space ). The reported suggestion was made by a cellular biologist I think and taken up by a couple of climate modelers to see if it would work. It doesn't mention that not a single move has been made to actually plant the desert or that anyone has even remotely taken this seriously in the public sector or in any government entity. Basically it was a study that some other scientist suggests equals the oil and gas industries inflated annual costs of sequestering the industries current level of CO2 pollution.


I might also mention that there is a plan to dump iron filings in the ocean and hope is encourages more algae growth. Course the guys who dreamed up that one were also planing on dumping these millions of pounds of Iron filings in one of the most environmentally sensitive areas of the ocean and a marine reserve to boot. It certainly looked like it was designed as a media ploy by the oil and gas industry PR machine. Didn't fool anyone with that one either.

deal is your just prevaricating and yes its kinda fun to dissect what the deniers are actually saying and show it to be exactly that, an intent to deceive. I call it "Find the Flaw" and its actually kinda fun.

The simple reality is that the theory of AGW and its successor Rapid Global Climate Shift are really quite sound and well respected within a huge scientific community so the odds that a denier actually has a valid beef with some aspect of it are seriously small. Means that in general your argument is flawed and its just a mater of finding it.

besides by pointing out the errors in the denialist diatribe the readers become more and more confident that there is a problem and that positive action needs to occur. Its important if we want our kids to enjoy a world anything like we had.

cheers
B

 

Go get 'em, Bos.

I don't have the time, ambition or resources to talk common sense to people; I'm too strung out between work and home. I'll cheerfully appoint you as my proxy...

 

Yeap, just us I thought.
Only for sport.

I tell you I would respect you more if you had a gig going. I say...even if paid in kind. Couple of chicken, case of wine, the occasional piglet.
But for sport?

I think you can do better Boston, but like my mother use to say, you can take the horse to the river but can not make it drink.

 

ya as I said its an educational tool that's kinda fun at times and kinda trying at others

its fun cause some of you guys come up with some really funny stuff and kinda trying cause some deniers get so incensed when the diatribe gets exposed again and again

If you want send a few cases of wine or say some kangaroo meet I'd be much obliged but really its not all that necessarily

 

The idea, obviously conjured up in the capitalist gulag could not work for a few simple reasons.

Firstly, eucalyptus is a water sucker. Whoevr had ever been to Australia would have seen that the soil under the eucalyptus forests is after millions of years still sandy.

Secondly, forests humidify the air. Humidified air (as we all know) retains the heat for longer, thus increasing the air temperature. Whoever lives near the sea, knows that 27 degrees Celsius feels a lot hotter than 35 Celsius in the mountains or in the desert. Because of the water content in the air.

So the geniuses with apparently doctorates to their names are jus a bunch of misguided ignorants. These simple facts are what every nautical officer studies in his first and second year, under the Meteorology subject.

The only solution is to reduce the population of the world. China is the only country actively doing it, albeit in a bit rough way (punitive measures). People being greedy shitheads, should be motivated to have max two kids through tax and other financial incentives, rather than punished for having moe than necessary.

Returning to eucalyptus, there is more to the plant that should disturb us about those cretens having the docotrates and expressing their opinion about possible solutions to global warmings.

Eucalyptus is quite a toxic plant. That is another reason why the soil under its' canopy is not fertile. Eucalyptus is not feeding the soli with necessary nutrients to provide improvement of the soil. And its' oils are insecticides too, destroying the food for birds and other animals that would further enrich the soil with their presence in the habitat.

Bugger, this thread is still alive...

 

And there you have it, in a nutshell.

 

Well, thank you for agreeing with me that this is not a very bright idea, but the reasons you list are not right.
IF... The idea has merit, the political / economical system that implements it is irrelevant, plants do not have any political affiliation.

"Eucalyptus is a water sucker" is a misguided generalisation. There are over 2000 species of eucalyptus and all of them can survive on little water and droughts that last 10 or 20 years. I don't think I need to remind the reader that we have trees growing on a few inches of poor soil above rock and no water. There are probably a few hundred species of eucalyptus that would do well in desert regions, within reason and reasonable establishment care. E. Saligna, Camandulensis or Globulus, the species most known to South America, are clearly not among them. By the way this species when planted in an alien environment that is abundant with water will take all they can since they are geared for drought and expect drought any time. In their natural habitat they flower every 4 or 5 years if that. In humid climate and deep soil they flower every year as if it was the last time.

"After millions of years the soil under the Eucalyptus is still sandy."
And it will still be sandy after another million years, since the mineral composition of soils can only be changed by catastrophic events like landslide, earthquake, floods. A tree can not alter the percentage of clay, loam or sand present and only has a moderate influence in the amount of organic matter that comes and goes for a variety of factors.

Here you are going out on a limb. The (alleged) purpose of planting a forest in a desert is to "cool down the planet". When I have difficulties even typing such blatant moronity of a concept, and when it is true as you say, that planting a forest would not cool down a damn thing, it is not because of the perceived temperature or the heat index, but because water vapour accounts for 96% of the Greenhouse effect that allows life on the planet. That's right, no greenhouse, no life. More water more greenhouse, more heat.
By the way, have you stopped to consider who decides what is the "correct" temperature? Who will turn the dial on the thermostat if we ever build one? Obama? Dolly Parton?

When I agree that China's violations of human rights is nothing to be proud of, your proposed child tax, would make a difference IF humans actually cause warming and IF such warming is in fact deleterious to life on earth. Two 'if' one on top of the other. A lot of IF. I think that is a bit iffy.

This is rather funny. The selection of a tree to reverse desertification or dune fixation has little to do with it's inherent toxicity to humans or other animals. Every plant has an ecosystem that works with it and another that works against it. The choice must be the one that can use the local environment to his own advantage. One particular location or desert may be good for it and another may not be. A lot of plants are toxic for specific reasons, reduce competition for water and avoid insect attacks is not a bad thing if you are stuck in one place for life.

 

One can argue that Boston's biased in his view... and wether its 50/50% view of AGW or not, or 82% consensus or 93% consensus or 97% consensus... or whatever.... (or Troy, Masrapido, (or even) Mark, Guillermo or me...).

Another question that can/ should be asked, why do they fail, getting the message out...? And no doubt, if they believe by their full heart, they should be very conserned by that part of the problem...

http://tigger.uic.edu/~pdoran/012009_Doran_final.pdf

Personally, i think this is worth some consideration...
(I think they're right, as some of you have noticed, but how/ why does the message "drown"?)

Maybe it's as easy as that they try to get a foothold for a political solution on what they see as the problem; they make it easy for the general public to identify the issue with politics.

Since when did we trust a politician...? Generally...?

edit; see also this link, its "rotated": http://www.gallup.com/poll/1615/Environment.aspx

 

interesting point
my take on that 97% is that its a reference to the scientific community specifically engaged in climate research, the public perception is about 60/40 and climbing, at least in this country. Reason its so low (60% really isn't all that great when you consider how overwhelming the data in support of the theory really is) is IMHO based on the agnotology campaign by the oil and gas industry. They likely spend as much money fighting public perception and awareness of the problem as there is total research money if not more.

according to
http://bearmarketnews.wordpress.com...-to-kill-climate-bill-push-offshore-drilling/
they spent roughly 2 billion just lobbying congress last year, which doesn't even remotely cover what they spent on PR and disinformation.

its a huge effort by the oil and gas industry to influence and coerce its way to greater and greater profits

from
http://www.spinwatch.org/-articles-...te-spin/16-internet-activism-vs-qdialogue-prq

 

This is where you start to lose it IMO.

Consider that the industry knows the resources are limited, that selling gas & oil is not a sustainable long term model.
Consider that the G&O industry has the infrastructure of distribution for any fossil fuel replacements.

Is it not just as likely that the industry is looking at what new replacement technology is going to be the best bet to continue their profits? Bio-diesel will come from the same pumps as fossil diesel won't it?

As the price of oil increases, alternatives that provide the same or higher profit margins will become attractive to the industry. When that happens look for competition for the new resource and a race to market with carbon neutral replacements.

Rather than punitive taxes on fossil fuels, whey not tax credits for alternate energy research? Either way the rice at the pump goes up, but at least with a tax credit for research the money would be going to address the problem, not into the general fund.

R

 

there are viable solutions available right now
only reason they are not employed "right now" is because some few mammoth multinationals (otherwise known as the corporate oligarchy) have a stranglehold on the system

for instance

this from a post I made on another site

so the argument has been had and the only logical conclusion is that if we want cost effective fuels we are going to have to provide them ourselves at which point the multinationals will be forced to either abandon there stranglehold on the oil and gas industry or jump on board and provide a the cheaper fuel

feel free to chew on that for a while and then get back to me with the industry spin cause frankly your last was pure industry PR

love
B

 

people think companies and industry sets policies

it's set by a few at the top to maximize their compensation and they won't be around when the consequences of their decisions have to be paid by the rest of us

they will be retired very wealthy, thank you

if the share holders actually had some say in how companies were run then maybe just maybe things would be different but they don't