Comment on “Extreme Level of CO₂ Accumulation Into the Atmosphere due to the Unequal Global Carbon Emission and Sequestration” by M. F. Hossain

Abstract

Rising atmospheric concentrations of carbon dioxide (CO₂) and other greenhouse gases are driving modern climate change and, therefore, are having substantial and sustained impacts on natural ecosystems and human populations. In a recent article in this journal, M. F. Hossain (2022. Water, Air, and Soil Pollution. 233:105) calculated how anthropogenic activity has perturbed the global carbon cycle, forecast future increases in atmospheric CO₂ concentrations, and discussed possible health consequences from rising CO₂ levels. However, Hossain’s article gave an inaccurate representation of how human actions have altered the global carbon cycle. He substantially underestimated the magnitude of anthropogenic disturbances in terms of CO₂ emissions from fossil fuel combustion and land use change and also underestimated the role of land and ocean processes in removing some of the emitted CO₂ from the atmosphere. At the same time, he overestimated the rate at which atmospheric CO₂ levels are increasing, resulting in a highly improbable forecast for atmospheric CO₂ concentrations later in this century. He also exaggerated the health impacts from exposure to those CO₂ levels as being severe and deadly, when our current understanding suggests that the direct effects are uncertain but likely minor. Because each of the major components of Hossain (2022) contains substantial and fundamental flaws, I warn readers to be skeptical before incorporating its findings into their understanding of carbon cycling, climate change, and human health.