Space: Science & Technology / 2021 / Article / Fig 4

Review Article

Biosphere 2’s Lessons about Living on Earth and in Space

Figure 4

Atmospheric CO2 levels and summer/winter incident light inside Biosphere 2. The Bar graph shows December 1991 sunlight vs. June 1992 sunlight. During this short day length winter period, CO2 was between 2100 ppm and 3700 ppm, while in the longer day length summer month, concentrations ranged from 800 ppm to 1700 ppm [10].