The rapid development of nanotechnology has created a variety of carbon nanomaterials (CNMs), such as cylindric carbon nanotubes, two-dimensional graphene, spherical fullerenes, leading to revolutionary progress in biology, medicine, chemistry, and physics. CNMs are inevitably released into the environment during production, transportation, and use, which raises questions about the ecological safety and health risks of CNMs. Recently, environmentalists and researchers have suggested exploring the possibility that microbial biodegradation technology could be a reliable and efficient method for the removal of CNMs from the environment, because several types of microbes have been found to successfully degrade CNMs. However, we do not agree with this opinion at this point because this technology is immature, and is still very much at the experimental stage. Most importantly, environmental CNMs are highly stable, where the carbon is often difficult to extract and use by microbes. (C) 2019 Elsevier Ltd. All rights reserved.