World temperatures are rising because of human activity, and climate change is now threatening every aspect of human life. Under this circumstance, carbon neutrality has been adopted as a feasible and effective way to mitigate negative impacts of climate change because it can reduce total greenhouse gas emissions.

Indoor air quality continues rising in importance as a public health issue in multiple industry sectors. Considering the current situation, more attention needs to be given into facilities such as hospitals and nursing homes in order to reduce the spread of COVID-19 through airborne transmission. Research indicates the coronavirus could remain in the air for more than eight minutes after talking. So, the indoor air quality should be frequently monitored and optimized, especially in times of change.