Biological Effects of Carbon Dioxide Enrichment

Increased CO2 concentrations can also “fertilize” plants by stimulating photosynthesis, which models suggest has contributed to increased vegetation cover and leaf area over the 20 century (Cramer et al., 2001). Increases in the Normalized Difference Vegetation Index, a remote sensing product indicative of leaf area, biomass and potential photosynthesis, have been observed (Zhou et al., 2001), although other causes including climate change itself are also likely to have contributed. Increased vegetative cover and leaf area would decrease surface albedo, which would act to oppose the increase in albedo due to deforestation. The RF due to this process has not been evaluated and there is a very low scientific understanding of these effects.