Environmental Science

Study of environmental systems and human impact on the natural world.

Basic Concepts

Cycles of Matter and Energy

Nature's Recycling System

Everything in nature is recycled! Water, carbon, nitrogen, and other elements move in cycles through the environment, making life possible.

The Water Cycle

Water evaporates from oceans and lakes, forms clouds, and falls back to Earth as rain or snow. Plants and animals use water, and it returns to rivers and oceans.

The Carbon Cycle

Plants absorb carbon dioxide (\(CO_2\)) from the air during photosynthesis and release oxygen. Animals breathe in oxygen and release \(CO_2\). Decomposers break down dead things, returning carbon to the soil and air.

The Nitrogen Cycle

Nitrogen in the air is converted by bacteria into forms plants can use. Animals eat plants, and nitrogen moves through the food chain. Waste and dead matter are broken down, returning nitrogen to the soil.

Energy Flow

The sun gives energy to plants, which are eaten by animals. Energy flows from one organism to another, but some is always lost as heat.

Why Does This Matter?

These cycles keep our planet healthy and support all life.

Examples

  • Water from melted snow nourishes plants, which are eaten by animals.

  • Dead leaves decompose, enriching soil for new plants.

In a Nutshell

Nature recycles water, carbon, and nutrients, keeping ecosystems running smoothly.

Key Terms

Photosynthesis
The process by which green plants use sunlight to make food from carbon dioxide and water.
Decomposer
An organism, like bacteria or fungi, that breaks down dead material.