How do flux estimates from CarbonTracker 2013 compare with previous releases?

The tables below summarize the estimated surface fluxes for combined natural sources and fossil fuel burning from the current CarbonTracker release (CT2013) and the previous releases (CT2011_oi, CT2010, CT2009, CT2008, and CT2007B). The uncertainty in the estimates is the one standard deviation from the filter estimate. Units are PgC yr-1 (1015 gC yr-1, or billion metric ton C yr-1, or 3.7 billion metric ton CO2 yr-1). Note that 2000 is excluded from long-term means as we consider it a "spin-up" year for our analysis.