Carbon dioxide is a gas consisting of part carbon and parts oxygen. It is one of the most important gases on the because plants use it to produce carbohydrates in a process called photosynthesis. Since humans and animals depend on plants for food, photosynthesis is necessary for the survival of life on earth.
As CO2 builds up in our atmosphere from burning fossil fuels, it has a warming effect that could change the earth’s climate.
Indoor carbon dioxide concentrations are driven by a combination of outdoor CO2, indoor breathing and the ventilation rate of the building. As buildings and homes become more energy-efficient and airtight, this means we have less fresh air.