The big climate news this week has been a surprise agreement between the Obama Administration and China to work together in curbing carbon emissions, but some think it's already too late for such measures to make a dent in global warming. That's led to a revival of interest in a more radical solution: Geoengineering, in which massive measures would be used to alter the planet and mitigate the effects of human burning of fossil fuels.
One such geoengineering solution, featured in a recent articles in the New York Times and the online publications Grist and Inhabitat, would utilize olivine minerals, a group of abundant green-tinted silicates that are formed from the cooling of magma after volcanic eruptions.
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In additional to having once been a favorite gemstone of the ancient Egyptians, olivine has another quality that intrigues geoengineering proponents: When left out in the open and combined with moisture under natural conditions, olivine absorbs carbon dioxide from the atmosphere and forms magnesium carbonate and silicic acid, which stores the carbon.
The mineral has been doing this on its own for billions of years, but Dutch geogchemist Olaf Schuiling advocates speeding up the process by crushing the rocks and spreading them on fields and beaches, and using them in everything from walking paths to sandboxes. Sprinkle enough olivine around, he says, and eventually it will remove enough C02 to slow the rise in temperature.
"Let the earth help us to save the Earth," Schuiling told the Times. He also advocates sprinkling it over the world's oceans, which would not only cause carbon absorption but also help to alter the waters' alkalinity and mitigate ocean acidification NEWS: Strange Visitors Appear in Warming Pacific
That may sound a lot easier than compelling utility companies to switch to renewable energy, or convincing consumers to stop buying fuel-hungry massive SUVs. But critics say that geoengineering with olivine may have some serious downsides, too.
A 2013 article on the Institute of Physics website notes that would take about 40 billion tons of olivine spread over the world's oceans to offset humans' current global C02 emissions, and that the energy required to produce that much ground rock would put back 30 percent of the carbon into the atmosphere. Peter Kohler, a scientist at the Alfred Wegener Institute for Polar and Marine Research in Germany who led the study on which the calculation is based, called olivine mining dispersal an"inefficient" solution to climate change. A January 2014 Nature article notes that grinding up that much rock might also create a lot of dust, which would be injurious to humans' respiratory health.
Nevertheless, Schuiling's idea of using olivine is gaining adherents. The National Academy of Sciences has been studying various geoengineering solutions to climate change and is scheduled to release a report this year.