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Showing posts from June, 2018

Ozone Cheats Found

In May of this year scientists reported that atmospheric levels of one of the most important ozone depleting gases, CFC-11, were not declining as quickly as they should be.  Modelling showed that new sources of CFC-11 out of east Asia were required to explain this worrying finding, and that these sources were large: 13 gigagrams per year of extra CFC-11 since 2012.  This was in apparent contravention of the Montreal Protocol, an international treaty ratified by all nations.  As I wrote at the time, possible sources included clandestine production of the banned compound and leaky stockpiles of old material. Reports soon emerged that leaking fridges were probably accounting for some of the emissions increases, and now an investigative piece by the New York Times has reported that factories in rural China are still manufacturing CFC-11 and releasing it to the atmosphere in the production of polyurethane foam.

These new reports are consistent with the initial scientific findings of increa…

Clean Coal on the Ropes

Clean coal is a seductive proposition for arresting climate change.  It means we could continue to burn coal for power as usual and use carbon capture and storage (CCS) to remove carbon dioxide from the flue gas and bury it underground.  Carbon capture is actually a mature technology, widely used in natural gas processing, where gas is bubbled through a liquid amine mixture which chemically binds to carbon dioxide, letting the desired gas pass through.  The amine solvent is then heated to liberate relatively pure carbon dioxide.
Companies and governments invested in coal have devoted massive resources to try and adapt carbon capture technology for coal fired power, with the typical approach being to bolt on a conventional amine solvent plant to an existing power station.  This approach has, however, failed to succeed.  The Boundary Dam project, a flagship effort aiming to demonstrate that CCS is feasible on an industrial scale, was plagued by budget overruns during construction, and