Comment on "Recent global decline of CO2 fertilization effects on vegetation photosynthesis".

Wang et al. (Research Articles, 11 December 2020, p. 1295) reported a large decrease in CO2 fertilization effect (CFE) across the globe during the period 1982­2015 and suggested that ecosystem models underestimate the rate of CFE decline. We find that their claims are artifacts of incorrect processing of satellite data and problematic methods for deriving and comparing CFE between satellite data and model simulations.