Washington: Emerging techniques to strip the atmosphere of carbon dioxide (CO2) and store it away to stabilise climate may become unavoidable, as our planet tips into a state of potentially dangerous warming.
Researchers from Columbia University's Earth Institute argue that upfront costs of directly taking carbon out of the air will be expensive, but such technology may become more affordable as it develops and is more widely used.
The techniques would address sources of CO2 that other types of carbon capture and storage cannot, and have the potential to even lower the amount of CO2 in the air—significant because the world may already have crossed beyond the point where the climate can be stabilised by just limiting emissions, the journal Proceedings of the National Academy of Sciences reports.
"The field of carbon sequestration, the field of capture and storage as a community is too timid when it comes to new ideas," said Klaus Lackner, director of the Lenfest Center for Sustainable Energy at Columbia, who led the study.
"You cannot rule out new technology simply because the current implementation is too expensive," he said.
Lackner and his colleagues at the Lenfest Centre of the Earth Institute summarise the technical and financial obstacles facing direct air capture of carbon in the review paper.
Lackner has been working on the problem for more than a decade, and he founded a company in 2004 to work toward commercialising the techniques, according to an Earth Institute statement.
Various methods are being developed to extract CO2 directly from stationary sources such as coal-fired power facilities and steel and cement manufacturing plants, storing the CO2 underground or using it for other purposes, such as feeding algae farms to produce biofuel.
But these systems do not address the problem of emissions from mobile sources such as cars, trucks and airplanes.
CO2 in the atmosphere, building up from humans' burning of fossil fuels and other activities, has led to warmer average temperatures across the globe, melting ice sheets and glaciers, raising sea levels and producing more frequent extreme weather events.
Nine of the 10 warmest years in the modern meteorological record since 1880, have occurred since 2000; the first six months of 2012 were the 11th warmest on record, based on land and ocean surface temperature measurements, according to the National Oceanic and Atmospheric Administration and the National Climatic Data Center.
CO2 can linger in the atmosphere for hundreds of years; to stabilise and possibly reduce it will take concerted, long-term efforts across the globe —including the replacement of fossil fuels as an energy source.
But the authors contend that is not likely to happen fast enough.
That's where carbon capture and storage comes in. These emerging technologies have the potential to nearly eliminate CO2 emissions from fossil fuel plants.