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Geoengineering wars: Another scientist teases out a surprising effect of global deforestation

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AUSTIN—A new and unpublished analysis of the regional impacts of a hypothetical scheme to mitigate global warming via radical deforestation was unveiled here Sunday at a gathering of science journalists and writers, on the heels of a blogging firestorm about geoengineering and climate change in anticipation of the release of Superfreakonomics: Global Cooling, Patriotic Prostitutes, and Why Suicide Bombers Should Buy Life Insurance.

The book, due out October 20, is the follow-on book by University of Chicago economist Steven D. Levitt and New York Times journalist Stephen J. Dubner, authors of the 2005 bestseller Freakonomics: A Rogue Economist Explores the Hidden Side of Everything.

Related research on the impact of deforestation has previously been detailed by various scientists including Ken Caldeira of the Carnegie Institution of Washington’s Department of Global Ecology in Stanford, Calif. In a 2007 paper in the Proceedings of the National Academy of Sciences, Caldeira used a 3-D climate model to mimic full global deforestation and found that by the year 2100, this approach would lower annual global mean temperatures by 0.5 degree Fahrenheit.

Taking the opposite tack, Caldeira had found in a 2005 paper in Geophysical Research Letters that replacement of all the Earth’s vegetation by forests would result in a 1.3 degrees Celsius increase in mean global temperatures. Alternatively, global replacement with grasslands would result in cooling of 0.4 degree Celsius.

Now, Caldeira is featured, reportedly not in a flattering light, in Superfreakonomics, drawing the attention of blogger and climate expert Joseph Romm who calls the book "error-riddled" and accuses it, in this Climate Progress post, of promoting global cooling myths and sheer nonsense. (Dubner responded in this October 18 blog post, which refers to Romm’s post as a "smear.")

Following up on the same geoengineering theme, Earth and atmospheric scientist Kevin Gurney of Purdue University offered similar details as Caldeira has found to attendees of the Council for the Advancement of Science Writing’s annual meeting of his modeling of what would happen in three latitudinal zones if all Earth’s trees were systematically stripped from land surfaces over time.

Like Caldeira, his modeling shows that at northern latitudes, the absence of trees would expose a lot of snow-covered surfaces that would reflect solar radiation away from Earth, resulting in global cooling in that region.

In the tropics, the opposite effect is found when all trees are stripped, according to Gurney’s model. Removing trees amounts to removing the source of water in the atmosphere, which means no clouds would form there. Clouds reflect solar radiation away from Earth’s surface, so eliminating them would result in global warming in the tropics. In that region, better results will come from efforts to slow down deforestation.

The deforestation results for Earth’s mid-latitudes is "muddled" and "generally a good thing," Gurney said.

The results, currently under review at a scientific journal, have difficult policy implications, Gurney said, whereby the United States could decide to use deforestation as a global warming mitigation effort to its regional advantage at the expense of people living in the tropics and mid-latitudes.

"I’m not suggesting that countries are going to do this but it makes a problem that is hard even harder," Gurney said, adding that it could complicate negotiations for a consensus at the U.N. Climate Summit in Copenhagen in December. "No one’s going to strip away all the trees, but there are strong incentives" domestically and elsewhere to engage in deforestation, he said.

An audience member asked Gurney if planting trees in northern latitudes would work to counter global warming, preventing the exposure of reflective snow. Gurney replied that there is not a lot of room in those latitudes to plant more trees "in a way that will cause a significant albedo effect," he said.

Gurney also detailed his Vulcan and Hestia projects that have modeled daily emissions of the primary climate-driving gas, carbon dioxide, as a result of the burning of fossil fuels, on fine space–time scales, potentially with a resolution of 25 meters. Vulcan focused on U.S. models for cities, whereas Hestia is going global. His "Breath of a Nation" video on YouTube illustrates the U.S. map in a 3-D animation and has been viewed more than 200,000 times.

The maps could be useful for local policy-setting, he said.



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  1. 1. Michael Hanlon 8:07 pm 10/19/2009

    See, I told you over at the "burning Bunnies" blog what the swedish order is to combat global warming:
    .1)Make the bullet.
    .2Drive to the site needing thinning.
    .3)Drink some hot coffee.
    .4)Make the gunpoder to propel the bullet.
    .5)Freeze(??) the carcass.
    .6)Ship the carcass.
    ,7)Thaw the carcass.
    .8)Drive off the water from the carcass.
    .9)Mix the remaining carbon with oxygen from a tree.
    .10)Cut down the tree.
    And someone already has this plan on their drawing board?Take that board away and buy him a new one. They’re cheap now that everyone’s gone digital, except of course for those idiot economists.

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  2. 2. jonderry 12:16 am 10/20/2009

    We’ve destroyed the environment so much that we need to destroy it some more to make it better?

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  3. 3. Shoshin 8:45 am 10/20/2009

    The point of this article is to show how ridiculous geo-engineering models can be. I’d like to know if any of these so-called "geo-engineering" schemes are actually proposed by real live Professional Engineers and not pseudo-wannabe engineers who are actually climatologists, economists or others of that ilk.

    The reason being, that in most jurisdictions, a Professional Engineer assumes legal liability for his or her actions. If the bridge falls down, their lives are ruined. For other "psuedo-engineers" such as research scientists, no such legal liability exists. They can be wrong and slink away.

    Maybe such a legal liability should exist. If you are claiming to be a climate expert, should not some liability be shouldered as well? After all, if you go to a brain surgeon and later find out that he’s really a tree surgeon who only wanted to be a brain surgeon, there are legal ramifications. Why not the same standard in the Climate Sciences? They are proposing massive costly projects using taxpayer funds; shouldn’t someone’s head be on the block if they are wrong?

    What would climate models look like if the the people constructing and promoting them them faced a real legal resonsibility for how closely their results reflect natures actions? I suspect a lot more sober thought would go into them. They way it is right now, the system is perverse; the more histrionic and alarmist the claim, the larger and more grandiose the proposed solution, the more attention and funding it attracts. That needs to stop if we have any hope of reclaiming the scientific process.

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  4. 4. rockjohny 2:40 pm 10/20/2009

    Makes me think that Satan has a few scientists by the nads…that’s absolutely NUTS lol. Trees, no matter where they are, help contribute to cloud formation that all helps reflect radiation back into space. But then some dumbass with a doctorate could project that clouds are bad because they insulate the earth at night therefore all trees should be cut down. "And he shall bring to ruin those ruining the Earth"….(at least they won’t finish their mission).

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  5. 5. Michael Hanlon 6:46 pm 10/20/2009

    If only facts and the truth were allowed to commerce, what of all our magazines and radio talk shows and yuotub and "Investigative Journalism" stories on cable and dish? We wouldn’t know that the balloon with the boy was lacking a ?? Boy!

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  6. 6. eco-steve 6:52 pm 10/20/2009

    Shoshin : Take a look at to see at least one example of efficient geo-engineering.

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  7. 7. alandaglish 4:18 am 10/21/2009

    It seems to be a given that all the doomsayers seem to need a lot more money to study the problem further and verify their models. When they can predict the weather more than a day in advance with better than 50% accuracy I will start to believe that a model of the earth a hundred years in the future stands a better than zero % chance of being correct. Hav’nt these peple heard of chaos theory. Perhaps the best way forward would be to eliminate all the butterflys, thus protecting the USA from major storms.

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  8. 8. Michael Cook 10:30 am 10/21/2009

    The best way to stop deforestation is for nations to get rich, especially rich enough that they don’t have to cut firewood just to cook or stay warm. The USA has more trees more places now then it did 100 years ago or 200 years ago, back when wildfires burned for months totally unchecked.

    In fact, even New York City has millions and millions of trees–something like 20% of their available area.

    jonderry whined about how egregiously humans have ruined the planet. Hey, fool, wait until the Yellowstone magma dome blows any year now. Probably 70-80% of all species on Earth will go extinct from starvation after the food chain is completely buried by falling ash and we plunge into a volcanic ice age for a couple centuries.

    Humans have barely scratched this planet. Pull your head out of your human-hating dogma hole. If you want real planet destruction you have to look at what nature does to itself. I saw Mt. St. Helens and its work firsthand 30 years ago–enormous destruction, deer, elk, and bears turned into crispy critters by the thousands, dead fish which couldn’t even float to the surface because water surfaces everywhere were covered over with blown down charred logs. Sulfpherous air, acid rain everywhere, toxic minerals ripped out of the Earth to pollute the streams, this is the power of vulcanism.

    St. Helens eruption in 1980 was only a tiny, tiny, tiny part of what the Yellowstone event will be, or maybe a tenth of what the coming Mt. Rainier event will be, and yes, there are other supervolcanos in the world as big as Yellowstone that could go at any time, not to mention the asteroid the size of the Mt. Rushmore monument that could come racing out of the asteroid belt with virtually no warning.

    Man does less than nothing compared to the really big and totally natural forces of destruction. Get real.

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  9. 9. Shoshin 11:15 am 10/21/2009


    You sound like an infomercial, constantly pushing biochar, but just out of polite curiosity, I will examine it.

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  10. 10. alandaglish 2:31 pm 10/21/2009

    Has anyone considered that we humans have a greater need for trees than we have for a .5 degreeF(Farenheight??) change in temperature 100 years hence?

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  11. 11. Sez Me 11:09 pm 10/21/2009

    @Michael Cook,

    Ahhhhh! So refreshing!. A breeze of sanity blows away some of the dust from "The Church of Global Warming Is All Caused by Man". Bravo Sir; bravo I say!!!

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  12. 12. way2ec 2:03 am 10/23/2009

    Let’s see if I can play Global Warming Predictions. We deforest only where there is snow so that we get the reflection thing going… and then we burn all the trees to make lots of clouds to block the light and thus lower temperatures, and those clouds reflect sunlight as well, but wait… don’t I have to calculate the rest of the impacts these actions might cause? Nah, these are scientists at work, not ecologists. Now for my next trick, the smoke and MIRRORS calculations. No, really, they are already trying to calculate cow farts in these models, so please, Dorothy, ignore the man behind the curtain.

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  13. 13. Wit'sEnd 11:18 am 10/23/2009

    If we don’t stop burning fossil and biofuels, all the trees will be dead from lethal levels of ozone and peroxyacetyl nitrates in the atmosphere.

    These toxic emissions are well-known to damage vegetation, interfering with the ability to photosynthesize and produce chlorophyll.

    The symptoms of this have been readily observable this past growing season on the foliage of all species of trees as well as annual plants, including crops.

    The forests on the eastern seaboard of the US are on the brink of ecosystem collapse and mass extinction. photos and links to scientific research at

    Are we going to wait for wide-spread crop failure and famine to figure out that we much switch to clean, green, renewable energy?

    Given the almost unanimous denial of what is perfectly obvious to anyone who cares to see, I guess so!

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  14. 14. eco-steve 6:37 pm 04/12/2010

    Shoshin : If I keep plugging biomass pyrolysis, it is because it has never received any government or private funding or support. Yet it has managed to provide the only economical process capable of eliminating CO2 from the air. Small farmers the world over can afford pyrolysis units, so they will inverse climate change while earning money, whereas politicians will deserve no merit at all.

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  15. 15. Nachthawk 4:46 pm 04/17/2010

    We have a few options.
    1) Warm with trees which increase precipitation, and thus vegetation.
    2) Warm without trees which will lead to desertification.
    3) Spend billions on other "geoengineering" VOODOO tricks, and still need to replant trees.

    How about cleaning up Chinas and Indias enormous pollution problems. Their brown clouds shade the ocean and reduce evaporation affecting rainfall amounts to the east, in addition to affecting the monsoon seasons.
    By-the-way, almost all of the eastern and southeastern U.S. was forested when European man arrived. Southern forests were cleared for tobacco and cotton plantations as well as homesteads. Additionally, entire forests were cut down in Wyoming and other areas to build the railroads. We don’t have more trees now.

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