Smithsonian National Museum of Natural History

Over-Reaction

At any given moment, many chemical compounds form, break apart, and reform in the air we breathe. Most of these atmospheric reactions occur naturally, often triggered by the sun, but human activity also influences them. While our ocean of air appears so vast that what we put into it seems inconsequential, chemical interactions among a tiny fraction of all the molecules in the air have the potential to undermine the delicate balance of life on Earth.

Life has always affected the atmosphere, but ever since people began to settle down and work the soil, they’ve played increasingly larger parts in atmospheric change. Take a look at the impact people have had on the atmosphere.