What is the Biosphere?

This chapter begins the unit that describes what we know and don't know about local and global ecosystems functions, the ways those ecosystems support life, and the ways human activity is affecting local and global environments.

You'll notice that for this unit (and, later, the Evolution Unit) I include some links to a dot com site, something I don't normally do. I made this exception, because I created the site, with the help of master teacher Marta Branch, to offer educational outreach for the film "After Earth." If you visit the home page at lifeafterearthscience.com, you'll see why I'm still excited about that project. You'll also see Untamed Science star Danni Washington join Jaden Smith to explain why certain aspects of global ecology are so important. (A Spanish-language version is in the works; I'll let you know when it's up and running.)

Lifeafterearthscience presents a "curated collection" of images and animations that bring global ecology to life for students. While you're there, be certain to check out the lesson plans Marta assembled. Some work with various chapters in this unit, others work with chapters in the Evolution unit, and some work with both units. The project arose, incidentally, because parts of the film were shot at the La Selva Biological Station of the Organization for Tropical Studies (OTS) in Costa Rica, where I co-direct an inquiry-based, professional development course for teachers.

Chapter 3 lays the groundwork for the unit by introducing important global processes and cycles. It can be hard to imagine how processes like primary production Ð which we think of as happening locally in plant leavesÐ could have global impact. Well, check out this animation from the Goddard Space Flight Center Scientific Visualization Service. It uses satellite data to demonstrate visually how primary productivity varies through the seasons, and how increases and decreases in primary production affect the CO2 concentration of the atmosphere within a few months! This animation could be entitled "Watching Earth breathe."

Why the Biosphere Matters

Earth is a living planet on which all forms of life are linked to one another, and to land, water, and air. Through those links, energy flows and matter cycles in paterns that support life, including human society. We know enough about these patterns to realize that they are changing, due to human activity, in ways we don't always understand. Our challenge is to study our impact on the biosphere and plan for a healthy future.