Abstract: Atmospheric concentration of CO2 has increased significantly over the past few decades and so have the concerns about the greenhouse effect and global warming. One of the extensively explored aspects is the response of ecosystem components in terms of performance and productivity. A host of information thus generated suggests a positive effect of elevated CO2 on functioning of plants from seed germination through maturation vis-a-vis rhizospheric microbial functions. Amazingly, most (if not all) of the researches deal with plant responses to CO2 at levels twice that of ambient with a view that fossil fuel burning and increased agricultural activity are adding substantially to the atmospheric CO2 . As such, hardly any attention has been paid to the contribution of soil respiration (includes that of microbes and plant roots) to CO2 concentration within the soil matrix as well as above the soil surface. This study presents an analysis of the available literature to demonstrate that by default the plant communities are already functioning at elevated levels of CO2 . Any further increase due to human intervention (especially fossil fuel burning) may not have a significant effect on plant functions and productivity. Hence the potential dangers of elevated CO2 resulting from fossil fuel burning should not be considered as alleviated through increased plant productivity.