Photo courtesy of Eric Golub via Flickr.

Space Mirrors And Sulfur Clouds: How Geoengineering Could Radically Change Our Climate

Photo courtesy of Eric Golub via Flickr.

As global warming seems inevitable at current emission levels, many have looked to radical geoengineering as a solution. However, deliberately altering the world’s climate may do more harm than good.

Geoengineering is defined (pdf) by the Intergovernmental Panel on Climate Change (IPCC) as “a broad set of methods and technologies that aim to deliberately alter the climate system in order to alleviate the impacts of climate change.”

These methods and technologies include massive-scale plans to place giant, sun-reflecting mirrors in space, seeding the oceans with iron to increase carbon-absorbing plankton, and injecting tons of sulfur dioxide particles into the atmosphere, volcano-style, to reflect sunlight.

Broadly, there are two methods of geoengineering, as outlined by the IPCC:

  • Solar Radiation Management (SRM), which modifies the amount of sunlight that reaches Earth

  • Carbon Dioxide Removal (CDR), which uses different methods to reduce the atmospheric concentration of the greenhouse gas CO2

Unforeseen consequences

Although none of these methods obviously have been proven on a large scale yet, they should be effective in reducing global warming.

In fact, leaked documents from the latest IPCC report show that the UN-sponsored body is considering geoengineering as a solution to the climate change.

But as the IPCC and others have noted, while the methods would likely be effective in reducing global warming, they could have unforeseen consequences.

For instance, both SRM and CDR geoengineering would reduce warming, but other effects of climate change such as more extreme weather and increased drought in dry areas would still occur, according to a December 2013 study in the Journal of Geophysical Research.

It also wouldn’t stop ocean acidification, could damage the ozone layers and reduce the potential of solar power in the case of SRM techniques, and be irreversible once completed, writes (pdf) Rutgers University researcher Alan Robock.

Geoengineering on the horizon

Research in this young scientific field could potentially be a violation of the 2010 UN moratorium on research affecting biodiversity, according to the Guardian.

Nevertheless, many programs have already been authorized by, among others, the U.S. Defense Advanced Research Projects Agency (DARPA), the Russian government, and the British universities of Oxford, Sussex and University College London.

The IPCC’s fifth climate assessment report will be released later this year, and it’s expected to include a large chapter on geoengineering – despite calls from green groups to avoid “legitimizing” such projects.

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Ole Skaar