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Scientists to NASA: We Need A Reliable Way to Track Global Emissions

By Keith Johnson

Forget all the haggling with China, India, and parts of the U.S. Congress - the real obstacle to a global climate-change treaty might be accurately measuring greenhouse-gas emissions in the first place.

That's the warning from the National Academy of Science's National Research Council to the head of NASA. The upshot? Without a sophisticated satellite that can track global emissions, it will be hard to know what everybody is really up to: "[C]urrent methods for estimating greenhouse gas emissions have limitations for monitoring a climate treaty."

NASA had such a sophisticated satellite - the Orbiting Carbon Observatory - which failed to reach orbit in February. The space agency is considering trying again - thus the letter from the NAS pointing out just how useful such satellites can be.

While the original satellite would have only flown for two years, and covered a small swathe of the earth, it could have provided accurate baseline information against which to measure global progress reducing emissions. Now, there's not even that much. Which complicates the whole climate fight, to say the least:

National emission inventories, required under the United Nations Framework Convention on Climate Change, are self-reported and are not required regularly for all countries. Verification requires checking these self-reported emissions estimates. However, independent data against which to verify the statistics used to estimate CO2 emissions, such as fossil fuel consumption, are not available. Existing instruments and methods for remote monitoring of atmospheric CO2 are not able, with useful accuracy, to distinguish fossil fuel emissions from natural fluxes or to verify trends in fossil fuel emissions, such as reductions against a baseline […] The existing atmospheric CO2 sampling network of ground stations, aircraft, and satellites is not well designed for estimation of emissions from large local sources distributed around the globe.

Whether or not NASA takes the message to heart, the scientists are hoping the Obama administration will: The letter was copied to both chief climate negotiator Todd Stern and presidential science adviser John Holdren.