Biosphere Basics

What is the Biosphere?

The biosphere is the combination of all ecosystems on Earth. Essentially, the biosphere is the zone on Earth where life is possible.

The biosphere covers all of Earth’s surfaces, extending from the ocean floor through the first layer of Earth’s atmosphere. While the biosphere measures about 12 miles (20 kilometers) wide, the majority of life exists in the range between ~1640 feet (500 meters) below Earth’s surface to 3.75 miles (6 kilometers) above sea level.

The biosphere overlaps and is inherently intertwined with three other geophysical spheres on Earth: Atmosphere, or Earth’s air (Module 2), Hydrosphere, or Earth’s water (Module 3), and Lithosphere, or Earth’s crust (Module 4).

What We'll Explore In This Module

This module will cover the basics of ecosystems to provide foundational knowledge for understanding how humans interact with, impact, and are impacted by other species throughout Earth's biosphere. We will first discuss systems: what they are, and what different types exist. We will then discuss the key role solar energy plays as the foundation of Earth's ecosystems, before discussing the cycling of energy and nutrients throughout ecosystems via food chains/food webs. We will learn about communities and habitats, including how species are spatially distributed on Earth's surface and how species interact. Finally, we will discuss the important role of biodiversity within Earth's biosphere.

The information contained in this module will be tested during the Biosphere Readiness Assessment Quiz during Week 3.