Estimating US fossil fuel CO <sub>2</sub> emissions from measurements of <sup>14</sup> C in atmospheric CO <sub>2</sub>
Sourish Basu, Scott J. Lehman, J. B. Miller, A. E. Andrews, Colm Sweeney, K. R. Gurney, Xiaomei Xu, John Southon, Pieter P. Tans
Abstract
accounting, even after adjustments for emissions that might be sensed by the atmospheric network, but which are not included in inventory totals. It is also larger ([Formula: see text]) than a similarly adjusted total from the US Environmental Protection Agency (EPA), but overlaps EPA's reported upper 95% confidence limit. In contrast, the atmosphere-derived estimate is within [Formula: see text] of the adjusted 2010 annual total and nine of 12 adjusted monthly totals aggregated from the latest version of the high-resolution, US-specific "Vulcan" emission data product. Derived emissions appear to be robust to a range of assumed prior emissions and other parameters of the inversion framework. While we cannot rule out a possible bias from assumed prior Net Ecosystem Exchange over North America, we show that this can be overcome with additional [Formula: see text] measurements. These results indicate the strong potential for quantification of US emissions and their multiyear trends from atmospheric observations.