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Compiled historical data sets for Δ14CO2 (top) and δ13CO2 (bottom) from Graven et al. (2017). Annual mean values of Δ14C are provided for three zonal bands representing the Northern Hemisphere (30–90°N), the Tropics (30°S to 30°N), and the Southern Hemisphere (30–90°S). Annual mean, global mean values are provided for δ13C.
