To Combat Global Warming, Carbon Dioxide is Turned Into Stone

                Scientists have found a quick way – but not a cheap one – to turn heat-trapping carbon dioxide gas into harmless rock. Experts say the results of a two-year, $10 million experiment called CarbFix, conducted about 540m deep in the rocks of Iceland, offer new hope for an effective weapon to help fight man-made global warming. When an international team of scientists pumped a carbon dioxide and water mix into underground basalt rocks, basic chemistry took over. The acidic mixture dissolved the rocks’ calcium magnesium and formed limestone, a permanent natural jail for the heat-trapping gas.

                Scientists, who had done this before in the lab, thought the process could take thousands or even hundreds of years. But after just two years, 95% of the gas, was captured and converted. One of the methods to battle climate change, in addition to reducing fossil fuel emissions, is to capture carbon dioxide from the air or powerplants. Carbon capture is not the silver bullet, but it can contribute significantly to reducing carbon dioxide emissions.

                Carbon capture however can be expensive – especially the capturing part. Once the gas is grabbed from the air, storage is another issue. It can be stored underground, injected in depleted oil wells, but there are concerns about monitoring it and preventing it from escaping. Injecting it into basalt and letting nature take its course can solve that problem. But at $17 per tonne of carbon dioxide, it can cost a couple times more than injecting it into old wells. There’s basalt all over the world, in places like the Pacific Northwest, India and South America. But even more promising is the ocean floor, which is full of basalt and a good place to store the carbon dioxide.