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Climate Change Solar radiation management technologies could cool Earth's climate

Published on October 18th, 2011 | by Silvio Marcacci


Can Geoengineering Combat Climate Change?

Solar radiation management technologies could cool Earth's climate

Editor’s Note: I’m totally in the same boat as Pat Mooney on this topic. We have the solutions we need today to solve global warming (without geoengineering). While some geoengineering solutions  (i.e. painting roofs white) are great, I wouldn’t trust our world leaders to safely or justly implement the larger ones for a second. Geoengineering could an even bigger disaster than global warming (one of the only things I can think of that could be). But it’s worth knowing how things are developing in this field, and these risky “solutions” should actually drive us towards faster installation of clean energy, in my opinion. So, here’s a piece from energyNOW! on geoengineering:

Climate change threatens an increasing list of worst-case scenarios: melting ice caps, rising sea levels, longer droughts, and more violent storms. Climate scientists have largely focused on reducing emissions to counter global warming, but a growing number view geoengineering as the Earth’s last, best line of defense.

However, the concept is controversial and unproven, and it’s unclear if it could work. energyNOW! correspondent Josh Zepps explores geoengineering, from simple measures to complex atmospheric efforts, to find out if it can combat climate change. The full video is available below:

Can Geoengineering Combat Climate Change? from Energy NOW on Vimeo.

Geoengineering, or climate engineering, is the study of manipulating the planet’s climate to counteract global warming’s effects. The potential solutions range from painting roofs white to absorb less heat, to launching trillions of transparent lenses a million miles into space to diffuse or divert sunlight before it reaches Earth.

Regardless of the method, the impact could be more significant than emissions reductions alone. “Geoengineering is the one way that you can potentially actually cool off the entire planet relatively quickly,” said Samuel Thernstrom, policy advisor at Clean Air Task Force. “It’s not clear that emissions can be reduced quickly enough to actually avoid fairly serious scenarios.”

The geoengineering technology most often discussed is imitating volcanic eruptions. This method is based on the 1991 Mount Pinatubo eruption, which spewed a cloud of sulfate particles so large it cooled the Earth by about one degree for a few years. The effect, called solar radiation management, would scatter solar radiation across the atmosphere and back into space.

A promising aspect of this approach is the ability to apply it to specific geographic locations through high-altitude balloons. “Maybe I don’t have to cover the whole globe with that volcanic aerosol,” said Michael MacCracken of the Climate Institute. “Maybe I can imitate a high latitude volcano and just have the sulfate at high latitudes over the Arctic Ocean.”

One of the first real-world geoengineering experiments will test this concept. The Stratospheric Particle Injection for Climate Engineering project (SPICE) is a tethered balloon with a hose more than a dozen miles long to spray reflective particles into the upper atmosphere, and it could begin in Britain as soon as April 2012.

Another way of managing solar radiation is to generate more ocean cloud cover. “If you could make these clouds denser and therefore brighter, they would reflect more sunlight,” said Thernstrom. “That is, at least theoretically, possible by spraying a very fine mist of salt water in the air, particles just the right size to help these clouds form.” Some estimates say 1,000-2,000 wind-powered, remote-controlled, seawater-spraying ships could offset global warming, at least for now.

But the concept is not without critics, who say geoengineering could wreak havoc on our climate. “They could also knock the Asian monsoon off course, having it swing below South Asia, meaning that there’d be famine in South Asia and affect Africa in ways we’re not even quite sure about,” said Pat Mooney, executive director of Canada’s ETC Group.

His concerns helped the United Nations impose a geoengineering moratorium in 2010. To Mooney, the only way to combat global warming is emissions reductions. “Those are real, credible solutions, and its not too late,” he said.

But for geoengineering advocates, having no backup plan at all is the worst option, given global emissions levels. “The whole problem is that we’re already interfering a great deal with the global climate,” said Thernstrom. “We are, in fact, engaged in a vast global geoengineering experiment right now – it’s just one that is entirely unintentional and uncontrolled.”

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About the Author

Silvio is Principal at Marcacci Communications, a full-service clean energy and climate-focused public relations company based in Washington, D.C.

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  • Anonymous

    Fresh info – just hit the web today…

    “One “geoengineering” proposal for reducing the impact of urban heat islands is to paint roofs worldwide a reflective white. Jacobson’s computer modeling concluded that white roofs did indeed cool urban surfaces. However, they caused a net global warming, largely because they reduced cloudiness slightly by increasing the stability of the air, thereby reducing the vertical transport of moisture and energy to clouds. In Jacobson’s modeling, the reduction in cloudiness allowed more sunlight to reach the surface.

    The increased sunlight reflected back into the atmosphere by white roofs in turn increased absorption of light by dark pollutants such as black carbon, which further increased heating of the atmosphere.

    Jacobson’s study did not examine one potential benefit of white roofs – a reduced demand for electricity to run air conditioning in hot weather. But a recent study done at the National Center for Atmospheric Research showed that the decrease in air conditioning use, which occurs mostly in the summer, might be more than offset by increases in heating during winter months.

    “There does not seem to be a benefit from investing in white roofs,” said Jacobson. “The most important thing is to reduce emissions of the pollutants that contribute to global warming.”"

    Must read article on urban heat islands. Jacobson and his group do some excellent work. They’re the ones who did the 100% renewables in 20 years study and the recent work on the contribution of black carbon/soot to Arctic melting.

    • Anonymous

      Wow, look at that, even the simple, “duh” solution might be the opposite of a solution after all.

  • Anonymous

    Thanks, Silvio!

  • Alden Moffatt

    Geoengineering experiments are already happening on a huge scale. Aluminum oxide is a fuel additive that makes jet fuel more energy fortified. Aluminum oxide is also a Wellsback material and Hughes Aircraft has a patent on stratospheric injection of Wellsbach materials to reduce sunlight. The patent was issued in 1991. Jet trails expand into huge clouds when the jet fuel contains aluminum oxide. Aluminum oxide is being found in extrordinary amounts in some areas where there is no reason for it, including in the snow fields of Mt. Shasta.
    People who have watched these trails for a long time call the expanded contrails Chemtrails. It’s a world wide experiment in full swing. Look up WXmod, radiative forcing, climate change remediation, stratospheric wellsbach injection, cirrus cloud seeding. The name changes often, but it’s all geoengineering.
    We should not be tampering with this cheap technology. Don’t forget, for every action, there is a equal and opposite reaction. This is a Frankenstein project.

    • Anonymous

      Thanks. Have heard about this here & there. Seems to be having some adverse consequences.

  • Anonymous

    I have an unformed opinion on geoengineering.

    I somewhat think it a bad idea to pursue as it might give some the feeling that we can fix the climate problem when it gets bad, thus allowing us to continue doing little or nothing to prevent catastrophic climate change.

    On the other hand I fear that we will do too little, too late. If we don’t start designing life boats now we might not have any available if we really need them.

    Perhaps research into geoengineering with tell those not amply concerned about climate change that 1) there is no way to turn off the bad stuff if we trigger it, or 2) the cost of the best geoengineering solution will be extremely expensive. Either of those outcomes might swing a few more people to the side of taking preventative measures now.

    I’d like to hear more arguments for and against. And I’d like to hear about any possible solutions which are affordable and largely non-destructive.

    • Anonymous

      I’m in a similar boat — you saw my note at the top of the piece. To elaborate, I’m also concerned about what you said. Also, though, painting roofs white (with non-toxic paint) is a basic solution that we should be doing and I’m sure there are numerous more we could come up with.

      The grandiose schemes look ridiculously expensive and/or look like they’d have serious side-effects we don’t want.

      Bottom line: nothing looks like it beats prevention.

      But if we’re going to be so dim, I hope someone with sense could think up some solutions that are not more harmful than helpful.

  • Lee Norton

    To date I have not seen any geoengineering that takes into account the acidification of our oceans. Ocean plankton accounts for about 70% of our oxygen and acidification is/will decimate the plankton’s ability to produce oxygen. 3 billion years ago or so, earth’s climate did not contain oxygen. Mammals (us) need about 20% oxygen to survive and our planet has provided this over millions of years. If the seas die, and they are dying, we will follow from the lack of oxygen. The problem is excess greenhouse gasses in our atmosphere such as CO2, CH4 and other man-made gasses. We must reduce these. We have the technology, we don’t have the political will.

    • Anonymous

      Good points.

      Yes, the ocean is the big topic hardly anyone is talking about.

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