The increase in atmospheric CO2 in the coming decades is nothing compared to how much CO2 increases in a closed room - for example a bedroom that you spend 8 hours in[1]. The paper you linked even notes this (exerpt below). This kind of alarmism just gives more ammunition to folks who want to entirely dismiss CO2 as a problem, but sure, let's keep ringing that bell.

> For example, The National Human Activity Pattern Survey (NHAPS) found that Americans spent an average of 87% of their time in enclosed buildings and ~ 6% of their time in enclosed vehicles in 1992–1994 (Klepeis et al., 2001). This has potentially increased since the COVID-19 pandemic (Young et al., 2024), with many people working-from-home in environments with poor mechanical air-ventilation (Nazaroff, 2021). The proportion of time spent in indoor, CO2 enriched environments could also contribute to the changes in blood chemistry noted in the NHANES data and is an important consideration in interpreting changes over time, and forecasts for the future.

[1] https://www.sciencedirect.com/science/article/pii/S036013232...