Turning CO2 into rocks

Since experiments began in 2014, it's been scaled up from a pilot project to a permanent solution, cleaning up a third of the plant's carbon emissions. "More importantly, we are a testing ground for a method that can be applied elsewhere, be that a power plant, heavy industries or any other CO2 emitting source", says Dr Aradottir.

The process starts with the capture of waste CO2 from the steam, which is then dissolved into large volumes of water. "We use a giant soda-machine", says Dr Aradottir as she points to the gas separation station, an industrial shed that stands behind the roaring turbines. "Essentially, what happens here is similar to the process in your kitchen, when you are making yourself some sparkling water: we add fizz to the water".

The fizzy liquid is then piped to the injection site - otherworldly, geometric igloo-shaped structure 2km away. There it is pumped 1,000m (3,200ft) beneath the surface. In a matter of months, chemical reactions will solidify the CO2 into rock - thus preventing it from escaping back into the atmosphere for millions of years.

"Before the injection started in CarbFix, the consensus within the scientific community was that it would take decades to thousands of years for the injected CO2 to mineralise", says Prof Gislason explains. "Then we found out that it was already mineralised after 400 days".

Some critics warn high-tech fixes such as this one pose a bigger risk - that of distracting researchers and the public from the pressing need drastically to reduce greenhouse gases levels. In a recent report, the European Academies Science Advisory Council warned that such technologies have "limited realistic potential" if emissions are not reduced. "CarbFix is not a silver bullet. We have to cut emissions and develop renewable energies, and we have to do CCS too," says Prof Gislason. We have to change the way we live, which has proved very hard for people to understand."

Either way, we're probably going to need some way to remove the carbon we've already put in the atmosphere.
http://www.bbc.com/news/world-43789527