Human population disrupts chemical cycles

Nutrient enrichment: when a nutrient cycle is disrupted and nutrients are taken away from one part of the biosphere and added to another where they build up excessively. It is especially dangerous if the material is toxic.

Acid precipitation: rain, snow, or fog with a pH below 5.6. Burning wood and fossil fuels lets sulfur oxides and nitrogen oxides out in into the atmosphere and they react with water to form sulfuric and nitric acid.

Biological magnification: toxins become more concentrated in higher levels of the food web.

Greenhouse effect: Earth absorbs heat due to gases, such as carbon dioxide and water vapor, which absorb infrared radiation and reflect it back to Earth.

Global warming is caused by burning fossil fuels, which increases the amount of carbon dioxide levels in the atmosphere.

The ozone layer protects us from harmful UV rays. It is a very thin layer that is being destroyed due to chlorine compounds such as CFCs. Many of these chemicals are no longer used.