Biogeochemical Cycles

The Earth recycles everything. Important elements like carbon, nitrogen, oxygen, and water move through the air, land, water, and living things in giant loops. These loops are called biogeochemical cycles. Bio means life, geo means Earth, and chemical means the substances involved.

How the Cycles Work

In each cycle, an element moves from one place to another. It might start in the air, get absorbed by a plant, eaten by an animal, and then returned to the soil when the animal dies. The element is never created or destroyed. It just keeps moving from place to place in an endless loop.

Why These Cycles Matter

Biogeochemical cycles keep the Earth healthy. The water cycle gives us fresh water. The carbon cycle balances carbon dioxide in the air. The nitrogen cycle gives plants nutrients to grow. When humans disrupt these cycles, such as by burning fossil fuels, it can cause problems like climate change.

Fun Facts

• The water molecules you drink today may have once been part of a dinosaur's body.
• Carbon atoms cycle through the environment and could be billions of years old.
• All biogeochemical cycles are connected. A change in one cycle can affect the others.

Did You Know?

The atoms in your body have been recycled through biogeochemical cycles for billions of years. The carbon in your body was once part of ancient rocks, ocean water, and even other living creatures!