Technology Review - Published By MIT
Log in to My.TechnologyReview.com | Register
Advertisement
« Back 1 2 [3]

Tuesday, February 13, 2007

Cooling the Planet

Continued from page 2

By Mark Williams

smaller text tool iconmedium text tool iconlarger text tool icon

On the one hand, such folks do have a point inasmuch as any global modification to the environment that went wrong would be a cure worse than the disease. On the other hand, it seems increasingly unlikely that a global agreement on emissions caps will be enacted anytime soon. The IPCC report claims that there is a high likelihood that Earth's climate has already moved past the point of no return and that sea levels will continue rising for millennia. Simultaneously, billions of people in China and India are arriving at the First World banquet table: according to the International Energy Agency, in two years China will pass the United States as the largest source of carbon emissions. "The political impossibility of what I call the prohibitionist agenda--that is, carbon prohibitionism--brings a kind of hallucinogenic quality to the global-warming discussion," says Benford. "No economist I know believes that global carbon emissions can be restrained within a century to even the level we have now. Every economist knows that the timescale for changing energy infrastructure is at least half a century to a century, just because of replacement costs. Economists are scientists too, and ignoring them isn't just blind: it's perverse."

Benford has a proposal that possesses the advantages of being both one of the simplest planet-cooling technologies so far suggested and being initially testable in a local context. He suggests suspension of tiny, harmless particles (sized at one-third of a micron) at about 80,000 feet up in the stratosphere. These particles could be composed of diatomaceous earth. "That's silicon dioxide, which is chemically inert, cheap as earth, and readily crushable to the size we want," Benford says. This could initially be tested, he says, over the Arctic, where warming is already considerable and where few human beings live. Arctic atmospheric circulation patterns would mostly confine the deployed particles around the North Pole. An initial experiment could occur north of 70 degrees latitude, over the Arctic Sea and outside national boundaries. "The fact that such an experiment is reversible is just as important as the fact that it's regional," says Benford.

Is Benford's proposal realistic? According to Ken Caldeira, a leading climate scientist at Stanford University and the Carnegie Institution's Department of Global Ecology, "It appears as if any small particle would do the trick in the necessary quantities. I've done a number of computer simulations of what the climate response would be of reflecting sunlight, and all of them indicate that it would work quite well." He adds, "I wouldn't look to these geoengineering schemes as part of normal policy response, but if bad things start to happen quickly, then people will demand something be done quickly."

Given that our social systems would crash without the economic growth that depends on the existing energy infrastructure that we have, Benford personally believes that governments can't be counted on to develop and deploy alternatives: "Anybody who thinks governments are suddenly going to leap into action is dreaming." Benford says that one of the advantages of his scheme is that it could be implemented unilaterally by private parties. "Applying these technologies in the Arctic zone or even over the whole planet would be so cheap that many private parties could do it on their own. That's really a dangerous idea because it suggests the primary actor in this drama will not be the nation-state anymore. You could do this for a hundred million bucks a year. You could do the whole planet for a couple of billion. That's amazingly cheap."

« Back 1 2 [3]

Comments

  • How mirrors can light up the world
    akay on 02/13/2007 at 1:19 AM
    Posts:
    4
    Avg Rating:
    5/5
    Mirrors to solve global warming are a good idea, however, down on earth, not up in the sky:

    Each square metre of desert receives sunlight equivalent to 1.5 barrels of oil annually, corresponding to a layer of oil 9 inch deep! The technology to tap this never ebbing well exists and is economically viable:
    http://www.ases.org/climatechange/

    Solar energy can be converted into electricity with 13 % efficiency by concentrating solar power plants (CSP) at a cost of $ 3-5 per Watt. CSP plants in California have been working reliably for 20 years.
    http://www.trec-uk.org.uk/articles/gdn_061127_ber_27_15216508.pdf

    With the amount of money spent in the “2nd oil war” (some $ 378 billion) one could trigger the construction of 300 GW of CSP plants, assuming $ 2 invested by private companies for each $ injected by the government. On a desert area of  7500 km2 (1.5% of the Great Basin) these would generate clean electricity equivalent to 3,000,000 barrels of oil per day, more than imported from the entire Persian Gulf region!
    http://www.ez2c.de/ml/solar_land_area/

    This would not only make us independent from Iraqi oil, but also save us and our children from climate disaster and radioactive waste as long as sun shines on earth. As a valuable by-product concentrated solar power can provide desalinated water to desert regions. Last, not least the construction of millions of mirrors from glass and steel would create countless jobs e.g. in the suffering automobile industry.

    The fever of mother earth cannot be remedied by chilling, but only by eliminating its causes! Man has conquered space and landed on the moon. Now we need an Apollo Program for earth, to save our spaceship before its climatisation runs out of control. If America shows the way to go, other countries like China will follow. But who knows, maybe China will show US the way? They are already ahead in the photovoltaic module market:
    http://www.renewableenergyaccess.com/rea/news/story?id=44457

    http://www.trec-uk.org.uk/index.htm
    http://www.energylan.sandia.gov/sunlab/index.html
    http://www.solarpaces.org/News/Projects/USA.htm

    Rate this comment: 12345
  • Cooling the planet
    deejay on 02/13/2007 at 1:52 AM
    Posts:
    22
    Avg Rating:
    3/5
    Hey, great ideas!!

    We've messed up the planet, and now instead of addressing the root cause, let's go and mess up space as well, by putting in the 'shadow'.

    This will assist us in doubling the amount of carbon dioxide, so that we can simply suffocate!! JKust tink about it, this will definitely solve the problem since, as Mr Bush says, its just us humans who caused it.
    Rate this comment: 12345
    • Re: Cooling the planet
      mkogrady on 02/13/2007 at 11:50 AM
      Posts:
      64
      Avg Rating:
      3/5
      The Cloud idea may not be so bad if the cloud itself is multi purposed. Why limit this to a shade device - what would happen if you made it our of thin folm solar materials that generate gazillions of watts of power for space based systems to use (telescopes, deep space radar and other goodies), and also provide a little Air Conditioning for the planet we live on. If there is a way to pipe the power to ground based collection systems, then we get power AND shade for the planet - not too shabby huh? The ROI model gets better, and can be sold to the general public a little easier if my thinking is right!
      Rate this comment: 12345
      • Re: Cooling the planet
        rluna on 02/15/2007 at 12:32 PM
        Posts:
        8
        If we send the energy back to earth, then heat waste from its use with heat up the earth.
        Rate this comment: 12345
  • attack the supply side
    dmorton on 02/13/2007 at 2:01 AM
    Posts:
    1
    Oil is the crack cocaine of industrialised societies. Just like in the war on drugs, we need to attack the supply-side.

    What we really need is a microbe that turns the oil in oilfields into something much less usefull and accessible. Either that, or a sustained bombing program on energy infrastructure.

    You tree-spikers out there better put your noggins to use spiking oilfields instead.
    Rate this comment: 12345
    • Re: attack the supply side
      rluna on 02/15/2007 at 12:40 PM
      Posts:
      8
      Or you can start a revolution or a war in a country that produces oil. That will scare investors causing an increase in the price of oil. An increase in the price oil has two opposite effects. First, oil companies are more profitable and as such more powerful. Second, increase in price causes a decrease in long run demand.
      Rate this comment: 12345
      • Re: attack the supply side
        Layne on 03/01/2007 at 3:08 AM
        Posts:
        2
        ...Or, instead of blaming McDonalds for fat people being fat, we can blame the fat people for making themselves fat, and hold them accountable. 

        In this case, that means the evil consumers of oil and meat (which is causing more greenhouse gas effect than petrol).

        (Sorry, I'm a newbie here, and not sure how serious or tongue-in-cheek the previous answers were.  Mine's serious.)
        Rate this comment: 12345
  • planetcooling with water
    Innovator-FS on 02/13/2007 at 5:05 AM
    Posts:
    1
    We are sitting on the solution! No need to go into the sky (which is tremendously costly).
    Why not cool the planet with water: abundantly available.
    Use sunlight to desalinate water. Huge amounts to be pumped into the desert zones of the planet:
    1. transfer sunlight into sweet water instead of reflection into the atmosphere
    2. tap water that comes anyway available from melting icecaps and glaciers (reduce rising of the sealevel?)
    3. develop plantlife in hughe areas to adsorb CO2
    4. help the people to extend the agricultural areal
    5. evaporation creates more clouds which reflect sunlight
    All necessary technology is freely available, we can start immediately at large and small scale.
    There are no still unknown risks to the planet and people when the system fails or hampers somewhere. (I rather not breath nanoparticles from the sky).
    Rate this comment: 12345
    • Replanet with water
      rluna on 02/15/2007 at 12:47 PM
      Posts:
      8
      what do we do with the brine that will be produced from the desalination. How will we power these desalination plants? I am going to guess oil. The increase in population will create more waste, maybe? This might also be the most expensive project proposed, desalination is expensive. The longest to show any results, deserts have horrible soil, and biomes take decades to go through ecological succession. It is my favorite, desserts would look nice with more vegetation.
      Rate this comment: 12345
  • A&B
    gabrielg01 on 02/13/2007 at 5:58 AM
    Posts:
    270
    Avg Rating:
    3/5
    A) I thought we could actively remove CO2 from the atmosphere. It could be stored underground. It would only take a few billion dollars to restore the CO2 balance - the Iraq war budget would definitely do.

    B) If you are still obsessed with mirrors, then you don't necessarily need a very large one. The further away you put it, the larger the shade will be - just make sure it is really a high quality mirror, so it reflects the energy and it does not get melted. And if you're still at it, then deflect that energy toward a cold planet, to aid in terraforming - Mars should do. Give Mars a 2nd Sun.
    Rate this comment: 12345
  • cooling the planet
    concerned1 on 02/13/2007 at 8:20 AM
    Posts:
    2
    Avg Rating:
    3/5
    What about "terra preta". Seems logical to me.
    Check this out: http://www.news.cornell.edu/stories/Feb06/AAAS.terra.preta.ssl.html
    Rate this comment: 12345
  • "Nuclear" winter the "cure" for Global Warming?
    nekote on 02/13/2007 at 8:43 AM
    Posts:
    98
    Avg Rating:
    3/5
    Loading the atmosphere with 1/3 micron particles of diatomaceous earth / silicon dioxide.

    A man-made non-radioactive version of the feared Nuclear winter?

    Tiny particles in the atmosphere are usually called pollution.
    And aren't very helpful when breathed into the lungs.
    Any likely effects on LEO satellites or space launches / re-entries?
    Rate this comment: 12345
    • Re:
      chipengineer on 02/18/2007 at 11:32 AM
      Posts:
      2
      These particles in the stratosphere would not cause any health issues. When they do eventually come down, they will be in rain drops or snow flakes.

      >Any likely effects on LEO satellites or space launches / re-entries?

      No effect on LEO satellites; the particles are not that high.

      I'm not as sure about re-entries, but the particle density is very small. More certainly, no manned re-entries are even done at the proposed high latitudes.
      Rate this comment: 12345
  • Easier way to reflect sunlight
    mbmurphy777 on 02/13/2007 at 10:45 AM
    Posts:
    14
    Avg Rating:
    5/5
    Much easier ways:

    Injecting sulfur based microparticles into the stratosphere

    http://ergosphere.blogspot.com/2006/04/braking-before-environment-crash.html#links

    http://www.springer-sbm.com/index.php?id=291&backPID=132&L=0&tx_tnc_news=2646

    It'd be hard to get agreement on this type of intervention, but it is worth looking into.

    Using sulfur based microparticulates delivered into the stratosphere could mitigate much of the expected warming, until there is a technological breakthrough in energy generation.

    Of course, playing with a complex system like climate can be dangerous (which is why agreement on even a pilot study will be difficult).

    Rate this comment: 12345
  • Mirrors in stationary orbit
    abcarterjr on 02/13/2007 at 3:40 PM
    Posts:
    45
    Avg Rating:
    3/5
    Werner Von Braun & Eberhard Rees gave a talk to my high school physics class outlining a scheme to
    influence Atlantic Hurricanes by heating the ocean
    water in the bight of Africa with reflected solar
    radiation from an orbiting mirror.I say when not used
    for hurricane modulation the mirror could keep an
    isolated part of the Atlantic Ocean warm enough
    to grow floating carbon sequestering biologicals
    or botanicals.
    Rate this comment: 12345
  • Living in Oz
    kitk on 02/14/2007 at 2:17 AM
    Posts:
    50
    Avg Rating:
    2/5
    Reading these comments, and the article, makes me think I should have watched Beavis and Butthead to be better accustomed with all this purile inanity. It is like watching willfull pre-teens on too many stimulants play with loaded guns. The earth is a huge, complicated system that includes the sun itself. Rushing to make some dramatic act--emulating the grade-B actors in a poorly written action film--will ensure little more than waste of money and much destruction of what you intend to save (except for your collective ego).
      We do not have anywhere near the knowledge to safely engineer planet-wide systems that fluctuate in natural cycles we always think are our own doing. Be a Geologist, and think very long-term.
      If you want to cut human CO2 emissions, advocate (and practice) self-control, self-education, less sex and the better raising of the kids we have now. Otherwise, you will just keep handing them all the mess you have made--again.
      Space mirrors are the stuff of Star Trek--at least 100 years down the road and sure to cause huge weather and crop problems if they actually work. So will high-altitude aerosols, along with possible cancer and asthma. Don't play Russian Roulette with the whole planet!
    Rate this comment: 12345
    • Re: Living in Oz
      mbmurphy777 on 02/14/2007 at 11:29 AM
      Posts:
      14
      Avg Rating:
      5/5
      As I noted, the atmosphere is complex.  The advantage of the sulfur aerosols is that they can be titrated (they only stay in position for a few years) slowly and carefully.... and would be a short term solution until newer technologies are able to deliver clean energy.

      Sure, any intervention will have risks, but the risks of runaway climate change are non-negligable.

      Expecting the world to adopt ascetic puritanical conservation is simply unrealistic.  Banking on that strategy in isolation to solve the GHG problems is foolish.

      Of course, the mirrors solution is unworkable, not just from a cost standpoint, but the solar wind would accellerate them out of position almost immediately... they'd essentially just be a huge solar sail afterall.

      Combined with CO2 removal (see terra preta post above), stratospheric aerosols might be reasonable temporizing measures until other breakthroughs are available.
      Rate this comment: 12345
    • Re: Living in Oz
      TMLutas on 02/18/2007 at 5:32 PM
      Posts:
      1
      The Stern report suggested that a $1T yearly investment in climate change would pay off over the next century. The estimated cost of a space elevator (development and deployment) is less than $1T. Deployment of such a system is feasible within the time frame where global warming is actually supposed to show up (as opposed to the fevered imaginings of alarmists who imagine that Katrina was global warming induced). That system drives cost to launch 1kg to $200 which takes the entire "space mirror" concept from impractically expensive to a reasonable expenditure of $20B in lift costs. In short, for less than 1 year of recommended expenditure by Stern, we get a fix that can lower temperatures significantly.

      It seems a rather foolish exercise in "moving the goal posts" to imagine catastrophic global warming in the next decade or two. Even the most alarmist of models do not foresee this level of change that soon. So why aim geoengineering solutions as short-term stopgaps?
      Rate this comment: 12345
  • There is hope btw
    rluna on 02/15/2007 at 2:58 PM
    Posts:
    8
    The proposed injection of silicon dioxide (which is sand by the way) would recreate the effects of global dimming. Now for those that are worried about potential pollution and unintended consequences, do not fret more sand will probably not pollute the earth. The name for pulverized sand is called loeses and most of northern china is made from it, some people even make their houses out of it. Second, we would not need to inject excessive amount in to the stratosphere as the sand is expected to last for a least a decade in the air. Lastly, it would fall back to earth at a rate that would be minute when compared to the sand blown into the air by the wind. The "space sand" solution should only be used as an emergency because decreased solar radiation results in decreased evaporation rates and decreased precipitation.
    In my opinion the cheapest and most effective way to stabilize world climate would be to reforest the world. Deforestation is one of the key causes of destitute poverty in the third world. We could kill two birds with one stone. The problem with this approach is that there is no economic incentive to do it.  However, using a combination of government regulators, private contractors, tax incentives, and carbon emission credit trading we could definitely create a workable model. This coupled with dissuading the practice of “slash and burn” for a more effective “char and burn” we could offset the effects of global warming. As for fossil fuels, we all know that as prices continue to rise we will see an increase in alternative fuels, and alternative fuel technology. With the help of government sponsored research and tax incentives, and government infrastructure investments we could be well on our way to an alternative fuel future. However, replacing our carbon based energy and automobile infrastructure in timely manner is not economically feasible. The only way to mitigate the effects of CO2 production is to increase the size of the world’s forest.
    Rate this comment: 12345
  • Feasible method of removing CO2 from atmosphere
    mbmurphy777 on 02/17/2007 at 8:11 PM
    Posts:
    14
    Avg Rating:
    5/5
    An engineer runs some numners:

    http://ergosphere.blogspot.com/2006/11/sustainability-energy-independence-and.html

    Pyrolyze biomass... waste as well as some dedicated energy crops (heat in a restricted O2 atmosphere), run the resultant pyrolysis gases (which contain about 1/2 the energy of the biomass) through a solid oxide fuel cell to convert them to electricity at 50% (already better than the standard 30% for steam turbines and rapidly improving) efficiency.  The rest of the biomass is converted into charcoal (pure carbon) and ash (minerals); the carbon can then be buried (or run through a direct carbon fuel cell to get more electricity).

    If buried, this will have the effect of sequestering the CO2 (charcoal is very stable and non toxic) out of the atmosphere (the biomass pulls it out of the atmosphere and incorporates it into the plant cell wall) allowing us to go carbon negative).  This would be about 30% of the biomass by weight.  The charcoal can even be blended into soil to improve crop yields (by helping soil to hold on to water and nutrients), thus replenishing lost top soil:

    http://www.eprida.com/home/index.php4

    As noted in this essay, the CO2 given off by the SOFC exhaust could be sequestered by algae, creating biodiesel and starch (which can be converted into ethanol).  This could then be used as transportation fuel or heating oil.  Alternatively, this could be fed back into the pyrolysis process to capture even more CO2.

    The biomass pyrolysis scheme noted above could replace a fair portion of fosil fuel consumption for electrical generation (50%, and that number could go up if SOFC efficiencies continue to climb)... thus displacing tons of CO2 production AND at the same time sequester nearly 1/2 billion tons of carbon (the equivalent of approximately 1.5 billion tons per year of CO2).

    It's a good read worth checking out, especially since I think energy independence is as important as GHG emission control!
    Rate this comment: 12345
  • Right up there with ripping out asbestos in the 80s
    evaneco on 02/17/2007 at 11:12 PM
    Posts:
    1
    When we found out asbestos was causing health problems in the 70s, we responded by hystericaly ripping asbestos out of every place we could find it, causing more harm in most cases than if we had simply left it where it was.

    When we found out FREON was harming the ozone layer (FREON being a substitute for ammonia that was killing people a generation earlier), we found many non-ODS substitutes now contribute to global warming.

    So now we gain a rudimentary idea of what are the actual mechanics of climate change and have zero chance of forseeing the potential problems with seeding the upper atmosphere with nanoparticles.

    And you want to do what?
    Rate this comment: 12345
    • Re: Right up there with ripping out asbestos in the 80s
      chipengineer on 02/18/2007 at 11:45 AM
      Posts:
      2
      >...have zero chance of forseeing the potential problems with seeding the upper atmosphere with nanoparticles.

      This experiment has been done naturally countless times - with major volcanic eruptions. The effect is clear in the temperature record, and is one of the better understood effects included in the climate models.
      Rate this comment: 12345
  • Cooling is much much MUCH worse than warming
    TallDave on 02/18/2007 at 5:51 PM
    Posts:
    1
    Maybe we shouldn't rush to the judgement that global warming is a net negative over the long run.  Even the most lurid global warming scenarios proposed don't begin to approach the devastation (massive crop failures, mass starvation, and if glaciation occurs the end of human civilization until the next interglacial) that we KNOW a sudden cooling event would create, and we don't yet know how unlikely those events are -- but we do know the Earth historically spent much of its time in an Ice Age environment that cannot support billions of human lives.

    We'd best do more looking before leaping.  We can always REDUCE solar radiation; increasing it would be vastly more difficult.
    Rate this comment: 12345
  • Cooling by ocean irrigation
    thomasjschum on 02/19/2007 at 10:00 PM
    Posts:
    1
    When the top layer of ocean gets too much warmer than underlying layers, mixing ceases. 
    To get around this we could use wave-action powered pumps to move nutrient-rich deep-ocean water to the surface where the nutrients will support plankton.  The plankton removes carbon and revitalizes the lowest layers of the food chain, sort of a double benefit.  A PDF drawing of this is the first download on my website.
    Website link is http://mysite.verizon.net/vzesfls5/files/
    Rate this comment: 12345
  • Global Cooling as Terrorism
    blunney on 02/20/2007 at 12:48 PM
    Posts:
    13
    Avg Rating:
    3/5
    "Applying these technologies in the Arctic zone or even over the whole planet would be so cheap that many private parties could do it on their own... You could do the whole planet for a couple of billion."

    Makes building nukes seem sort of Rube Goldberg, doesn't it?  All you need is a lot of sand, a lot of energy (to power the crushers and fans), and a pissy attitude - sort of like Iran!

    Seriously, the whole problem is economic in nature.  Two billion people with access to coal who want food, housing, electricity, modern conveniences and transportation NOW aren't going to worry about the consequences in fifty years.

    Today's beach house is tomorrow's beach front.  Mass dislocation and migration costs money and is messy.  Norway starts looking like a desirable address.  Things are going to change - get used to it. 

    The earth's climate isn't static, even if humans only burn our dinner, live in the grass, and chase wildebeests.  Civilization has just recently (like the last 100 years) stopped looking at the ground long enough to see what's happening in the sky.  No way are we wise enough to predict the long term  trends of the climate, much less our own actions.  Neither are we wise enough to admit it.
    Rate this comment: 12345
Advertisement
Advertisement

Current Issue

Technology Review May/June 2008
An Electrifying Startup
A new lithium-ion battery from A123 Systems could help electric cars and hybrids come to dominate the roads.
•  Subscribe
Save 41%
•  Table of Contents
•  MIT News

Magazine Services

Career Resources

MIT Technology Insider

Stories and breaking news from inside MIT about the latest research, innovations, and startups--in a convenient monthly e-newsletter. Subscribe today
Advertisement

More Technology News from Forbes

Advertisement
Advertisement
Advertisement