CO2 is a Vital Gas of Life

C4 plants, sugarcane, as seen from the air in Mauritius, Africa, 2011:0625. Photo: Hansueli Krapf (CC BY-SA 3.0)

Some people talk about CO₂ as if it were a toxic pollutant. Nothing could be further from the truth. CO₂ is a vital gas of life. Without it, all life (plants and animals) would die.

CO₂ is not carbon, it’s not soot, it’s not carbon monoxide (poisonous) and it’s not a pollutant. Here are some facts about the various levels of CO₂ that we’ve had in our atmosphere.

• At 0.00 ppm CO₂, all life dies.
• Below 150 ppm, all C3 species start to die. This is nearly 99% of our food crop species, leaving only pineapple, sugarcane, corn (maize) and a few other rarely used crops for all your meals. No more coffee, no more wheat toast and jam, no more orange juice, and no more chocolate.
• Below 800 ppm (2x today’s level), plants worldwide freaked out enough to evolve C4 species to cope with the CO₂ starvation.
• The average (normal) CO₂ level for the last 600 million years has been about 2,300 ppm (nearly 6x today’s level).
• The International Space Station typically has 5,000 ppm CO₂ for its astronauts.
• NASA’s recommended CO₂ maximum for long-term space missions is 7,000 ppm.
• Naval submarines typically have up to 10,000 ppm CO₂.
• NASA’s recommended CO₂ maximum for all space missions is 20,000 ppm.

Not Dangerous to Sea Life

Contrary to the modern hysteria, CO₂ is not a danger to sea life. Some have claimed that shellfish will no longer be able to make their shells with CO₂ levels higher than 400 ppm. This is nonsense. Shellfish evolved at a time when CO₂ in the atmosphere was between 4,500 and 7,000 ppm—far higher than today. Amazingly, life adapts to changes in the environment, sometimes within a generation or two. At the rate CO₂ is increasing, this will give hundreds of generations a chance to adapt.