Results show quick CO2 ‘fix’ feasibility – but its future rests in government hands

The CarbFix project is trapping natural CO2 emissions underground as Iceland seeks to offset emissions from other sources. Image credit: Reykjavik Energy

The CarbFix project is trapping natural CO2 emissions underground as Iceland seeks to offset emissions from other sources. Image credit: Reykjavik Energy

Although CO2 can stay in the atmosphere, trapping heat, for thousands of years scientists think they have turned it into rock in just a few months. Juerg Matter from the University of Southampton, UK, and his colleagues in the CarbFix project have injected 170 tons of pure CO2 into the reactive basalt underneath Iceland. Their findings suggest around 85% of it reacted with the rock over the short distance between injection and monitoring boreholes in less than one year.

“We think that was because all that CO2 precipitated out as carbonate minerals in the reservoir,” Juerg, who’s also an adjunct scientist at Lamont-Doherty Earth Observatory in New York, told me. “To really prove it this summer we will drill a borehole into the injection reservoir to retrieve rock core samples.” But the CarbFix team has also emphasised this week that it will take higher carbon prices for this and other carbon capture and storage technology to fulfil their potential.

The latest UN Intergovernmental Panel on Climate Change (IPCC) says the cheapest way to avoid dangerous climate change is to stop using fossil fuels and switch to renewable energy. However time’s running out on that option, and the IPCC report therefore highlights the probable need to suck CO2 from the air. But before we capture CO2 straight out of the air, or even from the chimneys of power stations, we need somewhere to put it. Currently captured CO2 is simply pumped and stored underground as a gas, meaning care is needed to choose reservoirs that won’t leak. “Storage options right now are mainly in depleted gas and oil fields, in sedimentary rocks,” Juerg said.

In the air, CO2 eventually reacts with basalt naturally, but that process is far too slow to balance out what humans are emitting. Since 2007 the CarbFix team has been working to see if they can speed that process up by forcing CO2 underground. Not only would this quickly turn the gas into minerals and prevent leak worries, it would also greatly expand the number of places it could be stored. “The storage potential is just huge, there’s billions of tons of reservoir, because basically all the ocean floor is basalt,” Juerg highlighted. Read the rest of this entry »

Fighting sea rise with mirrors and mock volcanoes

To fight sea level rise it might take pumping suphur dioxide emissions into the atmosphere equivalent to 1991's Mount Pinatubo eruption (shown here) every 18 months. Credit: USGS/Cascades Volcano Observatory

To fight sea level rise it might take pumping suphur dioxide emissions into the atmosphere equivalent to 1991's Mount Pinatubo eruption (shown here) every 18 months. Credit: USGS/Cascades Volcano Observatory

If CO2 emissions can’t be cut, simulating volcanoes could help the 150 million people across the world threatened by rising sea levels, scientists said this week. But the UK, Denmark and China-based researchers who reach these conclusions also warn such ‘geo-engineering’ measures could be dangerous in other ways. “Substituting geo-engineering for greenhouse gas emission control would be to burden future generations with enormous risk,” said Svetlana Jevrejeva of the UK’s National Oceanography Centre.

150 million people worldwide are thought to live within 1 metre of high tide, Jevrejeva’s team notes. In 2007, the Intergovernmental Panel on Climate Change (IPCC) estimated that by 2100 the sea level would rise by 0.18–0.59 metres. However, since then several researchers have suggested a rise of 1-1.5 metres would be more likely. Read the rest of this entry »