Which gas makes up about 0.036% of the Earth's atmosphere?

Carbon dioxide makes up about 0.036% of the Earth's atmosphere, a figure that highlights its relatively minor yet crucial role in environmental processes. This gas is vital for photosynthesis, allowing plants to convert carbon dioxide and sunlight into energy. While its concentration is small, changes in the levels of carbon dioxide can significantly impact climate and global temperatures.

In comparison, oxygen constitutes roughly 21% of the atmosphere and is essential for the respiration of most living organisms. Nitrogen dominates the atmosphere, comprising about 78%, and acts primarily as an inert filler. Hydrogen is present in trace amounts and does not play a significant role in the atmosphere's overall composition. Understanding the specific roles and concentrations of these gases helps clarify their importance in Earth’s systems and the delicate balance of the environment.