7.1 Ecological Footprints Read the lesson title aloud to students.

Learning Objectives Explain how the ecological footprints of typical Americans compare to the global average. Describe the Anthropocene. Click to reveal each of the learning objectives. Make sure students understand that at the end of the presentation, they should be able to explain the concept of an ecological footprint and identify the role of ecology in a sustainable future.

Our Changing Ecological Footprints Ecological footprint: the total area of healthy land and water ecosystems needed to provide the resources you use. Explain to students that to preserve ecosystem functions, each of us and our governments must recognize that long-term survival of our species depends on resource bases that are limited. Some cities and states and some countries are learning to address local ecological challenges through local actions. Tell students: Ecological science can help us understand our ecological impact and shape our future. Although science doesn’t have all the answers, ecological research can play an important role in helping us toward a sustainable future. Explain that ecologists often use a concept called an ecological footprint to help us understand our impact. An ecological footprint is the total area of functioning land and water ecosystems needed to provide the resources an individual or population uses and to absorb the wastes that individual or population generates. Ecological footprints include resources such as energy, food, water, and shelter, and wastes such as sewage and greenhouse gases. Tell students that the food they eat, the miles they travel, and the electricity they use all contribute to their—and the population’s—ecological footprint. Call on students to identify items representing uses of resources in the analogy, such as the boat, airplane, electric plant, and planted fields. Ask students to describe how the natural resources used for each item shown contribute to the community’s ecological footprint.

National and Global Ecological Footprints The average American has an ecological footprint over four times larger than the global average. Tell students that there is no single, universally accepted formula for calculating ecological footprints. Explain that although determining absolute ecological footprints is difficult, footprints can help make useful comparisons among populations, as shown in this illustration. To determine a country’s ecological footprint, researchers calculate the footprint for a typical citizen and multiply that by the size of the population. Tell students that according to one calculation, the average American has an ecological footprint over four times larger than the global average. Each average American uses almost twice the resources used by an average person in England, more than twice the resources used by an average person in Japan, and almost six times the resources used by an average person in China. Direct students to examine the map shown. Tell them that this world map shows each country in proportion to its ecological footprint. Tell students: The United States has an ecological footprint about twice the world’s average. By contrast, the African nation of Zambia has a footprint a little over one-fourth the global average. Click to highlight Zambia. Tell students to compare each country’s footprint size to its actual size on the smaller map below. Click to point out this comparison for the United States. Make sure students understand the color key and why the continents are shaped as they are. Ask: Why is North America so much larger than South America on this map? Answer: Areas that have larger relative footprints are shown to be bigger than areas that have smaller footprints. Tell students to compare the ecological footprints of regions and countries with the lesson opener image of Earth from space. (Return to slide 1 if necessary.) Ask: What do you notice about the areas with the largest ecological deficits? Answer: These areas—United States, Western Europe, South Korea, and Japan—are also the areas with the densest lights as seen from space, which makes sense because those areas are the most developed. Ask: How have you contributed to your ecological footprint today? Answer: waking up to a clock radio, turning on lights, using water to take a shower, flushing the toilet, preparing food for breakfast, wearing manufactured clothing, talking on a rechargeable cell phone, riding in a car to school, listening to music on a battery-powered MP3 player, sitting in a heated classroom

The Age of Humans The Great Acceleration Started during the 1950s Tell students that during the “Great Acceleration” nearly everything people did impacted global systems. In order to feed a growing population, we burned more fossil fuels, farmed more land enriched with fertilizers, and caught more fish. Medical and technological advances saved more lives and people lived longer. Explain to students that scientists now refer to this time as the Anthropocene, or “Age of Humans.”

Anthromes: Human-Altered Biomes Human-altered biomes are referred to as anthromes. Anthromes are globally significant ecological patterns created by long-term interactions between humans and ecosystems. Have students compare the land biomes map found in chapter 3, lesson 3 to the Anthromes map shown on this slide or in this lesson. Have them compare the categories of the biomes and the anthromes. Explain that anthromes are not “bad,” they are just a new way to classify areas based on human impact. Find your state in both maps and compare the differences. Have students identify the anthromes in your state.