Table 1 The effects of increasing CO₂ concentrations in the air on human health (after Ikeda et al. 1989; Hathaway et al. 2004; Hansell and Oppenheimer 2004; Hansell et al. 2006; Cantrell and Young 2009)

5

perceptible increase in respiration

6 to 10

shortness of breath, headaches, dizziness, sweating, general restlessness, visual disturbances, tremors

10 to 15

impaired coordination and abrupt muscle contractions, tachycardia

20–30

loss of consciousness and convulsions

>30

can result in death in 1–10 min