4. Earth’s atmosphere contains about 78% nitrogen, 21% oxygen and less than 1% other gasses, including only .0400% CO2.
Earth's atmosphere consists of approximately 78% nitrogen, 21% oxygen, a varying 0 to 4% of water vapor at any one place and a small, 0.0400%, amount of CO2 and a few other trace gasses. The amount of CO2 in Earth's atmosphere is very small but that small amount delivers a huge impact on the plant and animal kingdoms. By simply increasing this small amount of CO2 almost twofold, thousands of peer reviewed studies indicate that the result would be a tremendous "greening" of Earth as well as most individual ecosystems and habitats. To actually reduce CO2 levels as some extremists groups propose, would be catastrophic to the hundreds of millions of people (and animals) currently living on the edge of starvation.