Environmental chemistry

Atmospheric chemistry, ozone depletion, the greenhouse effect, and pollutants

What is environmental chemistry?

Environmental chemistry studies the chemical processes happening in the air, water, and soil around us — including how pollutants move through the environment, how natural systems break them down (or fail to), and how human activity changes the chemistry of the planet.

The atmosphere's chemistry

The air around us is a mixture of gases in constant chemical motion. Sunlight drives chemical reactions high in the atmosphere, including the formation of the ozone layer, which absorbs harmful ultraviolet radiation from the Sun and protects life on Earth's surface. Lower in the atmosphere, pollutants released by vehicles and industry can react with sunlight and other chemicals to form smog, and greenhouse gases like carbon dioxide trap heat, warming the planet's surface.

Water chemistry

Water is an unusually good solvent, which means it readily dissolves and carries a huge range of substances — both beneficial nutrients and harmful pollutants. Understanding water chemistry is essential for making drinking water safe, treating wastewater before it's released back into the environment, and tracking how pollutants move through rivers, lakes, and groundwater.

Pollutants and how they break down

Not all pollutants behave the same way once released into the environment. Some break down relatively quickly into harmless substances through natural chemical or biological processes; others persist for a very long time, sometimes building up in the environment or in living organisms as they move up the food chain. Understanding a pollutant's specific chemistry — how it reacts, how long it lasts, and where it accumulates — is essential for assessing its real-world risk and for designing effective cleanup methods.

Why environmental chemistry matters

Environmental chemistry provides the scientific foundation for setting safe pollution limits, designing water and air treatment systems, cleaning up contaminated sites, and understanding and addressing large-scale environmental challenges like ozone depletion and climate change.