what percent of the atmosphere is carbon dioxide

Carbon dioxide makes up about 0.04% of the Earths atmosphere. While this may seem like a small amount, it plays a significant role in global warming because of its ability to absorb heat emitted from the Earth's surface. Of the remaining 1% of the atmosphere, the main molecules that can absorb infrared radiation are CO2 and water vapor. The concentration of carbon dioxide in Earth's atmosphere is currently at nearly 412 parts per million (ppm) and rising, representing a 47% increase since the beginning of the Industrial Age, when the concentration was near 280 ppm. Humans have contributed about one-third of the CO2 in the atmosphere since 1850.