The study investigates the impact of ambient carbon dioxide (CO₂) concentration on the aerostability and infection risk of SARS-CoV-2. It finds that a moderate increase in atmospheric CO₂ levels (e.g., from 500 ppm to 800 ppm) significantly enhances the aerostability of SARS-CoV-2, leading to a substantial increase in the overall risk of COVID-19 transmission. The research uses the Controlled Electrodynamic Levitation and Extraction of Bioaerosol onto a Substrate (CELEBS) technique to systematically explore the effects of environmental factors such as CO₂ concentration and relative humidity (RH) on the aerostability of SARS-CoV-2 variants. The results show that the BA.2 Omicron variant is more aerostable than the Delta variant, and that the aerostability is influenced by the pH of the aerosol droplets, which is affected by the CO₂ concentration. The study also demonstrates that the Wells-Riley model, which is commonly used to estimate the risk of indoor transmission, can be improved by incorporating the effects of CO₂ concentration and RH. The findings highlight the importance of maintaining low CO₂ concentrations and improving ventilation in indoor environments to mitigate the risk of respiratory disease transmission.The study investigates the impact of ambient carbon dioxide (CO₂) concentration on the aerostability and infection risk of SARS-CoV-2. It finds that a moderate increase in atmospheric CO₂ levels (e.g., from 500 ppm to 800 ppm) significantly enhances the aerostability of SARS-CoV-2, leading to a substantial increase in the overall risk of COVID-19 transmission. The research uses the Controlled Electrodynamic Levitation and Extraction of Bioaerosol onto a Substrate (CELEBS) technique to systematically explore the effects of environmental factors such as CO₂ concentration and relative humidity (RH) on the aerostability of SARS-CoV-2 variants. The results show that the BA.2 Omicron variant is more aerostable than the Delta variant, and that the aerostability is influenced by the pH of the aerosol droplets, which is affected by the CO₂ concentration. The study also demonstrates that the Wells-Riley model, which is commonly used to estimate the risk of indoor transmission, can be improved by incorporating the effects of CO₂ concentration and RH. The findings highlight the importance of maintaining low CO₂ concentrations and improving ventilation in indoor environments to mitigate the risk of respiratory disease transmission.