Understanding Environmental Chemistry

The chemistry of our environment consists of several elements, mostly oxygen, nitrogen, water vapor and carbon dioxide. The interplay of all of these chemicals has a major impact on life on Earth for animals, plants, and humans. An excess or deficiency of any of the vital atmospheric elements can have far-reaching effects on the environment as a whole. Here is a basic guide to understanding environmental chemistry.

Understanding environmental chemistry: The atmosphere

The basic elements of environmental chemistry are nitrogen and oxygen. We often think of the atmosphere as being comprised mostly of oxygen, but it is only 21% oxygen. 78% of the atmosphere consists of nitrogen, with water vapor, carbon dioxide, and several other elements making up the last one percent. Nitrogen, which comprises most of our environmental atmosphere, is generally nonreactive on its own. It must be converted by an organic compound like an amino acid before it can react with most other chemicals.

Understanding environmental chemistry: Oxygen

Even though it is only 21% of the air, oxygen is crucial for life. Humans and plants both depend on oxygen being present in the environment. Obviously, humans need oxygen in order to breathe. Plants rely on carbon dioxide created from the breathing of humans and animals. Oxygen is also vital to the decaying process of organic matter, which introduces more carbon dioxide into the atmosphere. Without carbon dioxide, the photosynthesis process cannot convert water and nutrients into energy.

Understanding environmental chemistry: The water cycle

The water level of the environment is always in flux. Water evaporates when it warms, turning into vapor and rising into the atmosphere. The water vapor then condenses and falls back to the ground as rain or snow. Moving bodies of water such as rivers or streams bring this precipitation back to the ocean, where the environmental water cycle begins again.

Understanding environmental chemistry: Greenhouse gases and climate change

Of course, no discussion of environmental chemistry would be complete without mentioning the harmful effects of humans on the atmosphere. Most people have heard of "greenhouse gases" by now, but what exactly does this mean? A greenhouse gas is not poisonous when breathed in, but it can reflect the Earth's heat back down onto itself instead of letting it escape into space. Over time, this trapped heat leads to climate change and environmental disaster. Carbon dioxide is a good example of a greenhouse gas. In normal amounts, it is beneficial, even vital, to plant life and human survival on this planet. However, it causes significant problems when there is more carbon dioxide in the atmosphere than the plants can process.