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AGU Fall Meeting: Spying on carbon

At last year’s AGU Fall Meeting, environmentalresearchweb spoke to David Crisp of NASA to find out more about the Orbiting Carbon Observatory (see http://environmentalresearchweb.org/cws/article/research/32196). Since then, progress has been good and the satellite is due for launch sometime after January 30th 2009 from an air force base near Los Angeles.

Speaking at a press briefing, Crisp’s colleague Scott Denning detailed how the observatory will help us find out more about Earth’s carbon sinks. Currently these vary in the amount of carbon they absorb from year to year and nobody knows why. “Some years almost all the fossil carbon enters the atmosphere, some years almost none,” he said. “On average it’s about half.”

This variability adds to the uncertainty of our climate future, especially as we don’t know how land and ocean uptake will change in the long-term. Denning says that by the end of the century it’s estimated that the ocean could be absorbing between 3 billion and 9 billion tonnes of carbon a year. The land, meanwhile, could be taking up as much as 11 billion tonnes or even acting as a source of 6 billion tonnes a year if there are large amounts of forest and ecosystem dieback. So depending on how this plays out, the same levels of human emissions of carbon could lead to atmospheric levels of carbon dioxide that differ by up to 300 parts per million.

What’s more, with the introduction of systems such as the European Carbon Exchange, carbon sinks are becoming a commodity. On November 11th of this year, the price of carbon on the exchange was $102 per tonne. Earth’s carbon sinks currently absorb around 4 billion tonnes of carbon a year: to buy that amount of carbon removal on the exchange (assuming it were available, which it isn’t) would cost $408 billion. As Denning put it, “that’s a lot of money even by bailout standards”.

 

Posted by Liz Kalaugher on December 19, 2008 11:18 PM | Permalink