Climate change discourse is filled with negative stories: every day the media is telling us about melting ice, starving polar bears and dying coral reefs. Sometimes these stories can obscure climate action’s successes stories, even though science has come up with a number of amazing solutions to adapt to and mitigate global warming. In addition to enthusiastic but purely theoretical ideas of putting huge “sunglasses” around Earth to shade the tropics or wrapping Greenland in reflective blanket, other technological solutions are already in place and tested for effectiveness. One example is Carbon Capture and Storage (CCS), a self-explanatory negative emission method where “negative” is actually positive and refers to the removal of carbon from the atmosphere. Carbon is captured from the atmosphere and ejected into a storage site, usually a highly permeable rock.
Previously, the potential of CCS has been questioned due to its high costs, time extent before carbon solidifies into rock, and risks associated with trapped CO2 leakage. The estimated costs of CCS ranged between $50 to $100 per ton of CO2 sequestered and expect to take hundreds or even thousands of years for captured carbon to solidify. Scientists also feared that fissures in the rock layers could allow some carbon dioxide to escape.
However, a study published in Science in 2016 by Matter and others (2016) on the success of their CarbFix Project brought the CCS discussion back to the table. An Iceland-based research team has successfully sequestered atmospheric carbon dioxide by injecting it into basaltic rocks; it took for the injected CO2 less than two years to mineralize, way faster than the scientists expected. By using this mechanism, the technology allows not only reduce the amount of carbon dioxide in the atmosphere, but permanently sequester it in the rock, a geological weathering at extremely accelerated pace.
Source: Matter et al. (2016). https://doi.org/10.1126/science.aad8132
Further, this novel project addressed the problem of where to store the captured gas and minimize the risk of leakage. As Science Magazine (Kintisch, 2016) reports, previous CCS “used formations of sedimentary rock, often sandstone harboring briny groundwater or depleted oil wells, because industry has long experience in working with them”. By contrast, CarbFix researchers injected CO2 into underground layers of volcanic rocks known as basalt, and carbon dioxide reacts relatively quickly with this type of rock to create carbonate rocks. Unlike sandstone, the basalt contains metals that react with CO2, forming carbonate minerals such as calcite—a process known as carbonation (Kintisch, 2016). The geology of Iceland played a key part in success of this project: basalt is found all across the island.
The scientists are now exploring similar possibilities with vastly greater storage potential beneath the oceans off the U.S. coasts, and they are experimenting with a type of rock found in abundance in Earth’s mantle that could be used to go the next step and begin taking CO2 out of the environment (Morford, 2016). In 2017, CarbFix teamed up with Swiss startup Climeworks to scale up the CarbFix approach on a global level; the team set itself the goal of capturing one per cent of global CO2 emissions by 2025. The same year, Climeworks switched on a first carbon capturing plant in Switzerland.
This technology has received support from many governments in Europe and North America. CarbFix project was originally encouraged by Iceland’s President who sought to make his country the leading example of clean energy. On the other side of the ocean, the US 2018 budget bill included an increased number of energy tax for the development of renewable energy, a separate measure would greatly expand a tax credit for companies that capture carbon dioxide from power plants or other polluting facilities and pump it underground (Sanger-Katz, 2018).
Despite the allure of this technology, it comes with drawbacks. Some scientists fear that negative emissions might not work as effectively as advertised, or have serious side effects that. The CarbFix project, for example, sequestered only about as much carbon as a typical U.S. family produces in a year (Grossman, 2017). Further, CCS was criticized as “politically-appealing panacea that postpones the need for rapid and immediate mitigation and justifies further use of fossil fuels (Anderson & Peters, 2016).”
Certainly, CCS is not the ultimate solution to climate change; we still need to significantly reduce the greenhouse gases emission, on individual, national and global levels. However, it illustrates the potential of technology to mitigate climate change and offers a glimpse of hope in the depressing discourse around climate change. We need to change our actions to reduce the effects of climate change, but we also need to change the way we present the issue. The rhetoric of irreversible catastrophic warming is not very conducive to motivating people to act; blind hope that we will miraculously escape climate change’s consequences is just as ineffective. As Dr. Greg Asner, a lead scientists at Stanford’s Carnegie Airborne Observatory, put it, “we need to change this negative media story and turn it into a positive one. But we need to do so not just by simply basing it on hope, but basing it on the science and conservation-based hope.”
Anderson, K., & Peters, G. (2016). The trouble with negative emissions. Science, 354(6309), 182. https://doi.org/10.1126/science.aah4567
Grossman, D. (5 May 2017). Pros and cons on ‘negative emissions’ prospects. Yale Climate Connections. Retrieved from: https://www.yaleclimateconnections.org/2017/05/pros-and-cons-on-negative-emissions-prospects/
Kintisch, E. (10 June 2016). Underground injections turn carbon dioxide to stone. Science Magazine. Retrieved from: htttp://www.sciencemag.org/news/2016/06/underground-injections-turn-carbon-dioxide-stone
Matter, J. M., Stute, M., Snæbjörnsdottir, S. Ó., Oelkers, E. H., Gislason, S. R., Aradottir, E. S., … Broecker, W. S. (2016). Rapid carbon mineralization for permanent disposal of anthropogenic carbon dioxide emissions. Science, 352(6291), 1312. https://doi.org/10.1126/science.aad8132
Morford, S. (25 Oct 2016). Turning CO2 to stone. PHYS. Retrieved from: https://phys.org/news/2016-10-co2-stone.html#jCp
Sanger-Katz, M., Plumer, B., Green, E.L., Tankersley, J. (8 Feb 2018). What’s Hidden in the Senate Spending Bill? The New York Times. Retrieved from: https://www.nytimes.com/2018/02/08/us/politics/senate-spending-bill-taxes-medicare.html