Scientists believe that solidified lava and magma could perhaps safely store large amounts of the greenhouse gas carbon dioxide and help combat global warming. Basalt, the “bubbly” black rock that is formed when lava cools, has the chemical potential to help take up carbon. So, does peridotite, the greenish-black rock formed when magma cools deep in the Earths mantle. Magnesium or calcium ions in the rock lock up the carbon dioxide in the form of a stable, solid carbonate like chalk or the Tums tablet you might pop in your mouth after a rich meal. Earth scientist Juerg Matter, who led a pilot study that injected carbon dioxide deep into the basalt rock that makes up much of Iceland, says his results are promising. While the scientific literature and experimental laboratory data have long suggested that mineralisation of carbon dioxide takes hundreds or thousands of years to occur, Matter says his project showed that within less than two years, all the CO2 his team injected into the rock was mineralised. The project is now expanding, with support from several European research institutes, and similar experiments are underway in other parts of the world. The feasibility and cost of this method of capturing and storing carbon are still uncertain. But scientists know one thing for sure: Basalt is ubiquitous. It covers large areas of India, the Pacific Northwest and Iceland. In fact, basalt covers more of the Earths surface than any other type of rock. So, in a twist of fate, there is a chance that someday ancient hot lava might just help our world cool down.
Public Radio International, 3 June 2018 ; http://www.pri.org