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U.S.A. 17


This nighttime image of the world was taken from space. It shows where electricity lights up our world and where it does not.

Life on the Grid Remember that grid? T e bright lights on this map show areas where people live on the grid and rely heavily on fossil fuels. In the United States, over 80 percent of our energy comes from fossil fuels. In China, that percentage jumps to 93 percent. Using fossil fuels not only depletes the

planet’s resources. It also releases a lot of carbon dioxide and other materials, which harm the environment. T ey create a layer of gases in the atmosphere. T is layer traps the sun’s energy close to Earth, which warms Earth’s overall climate.




Carbon Footprint As the Earth grows warmer, some environmental problems develop. Sea levels rise and weather patterns change. A country’s carbon footprint summarizes the amount of fossil fuels a country uses. People in countries with larger carbon footprints use more fossil fuels for everyday tasks—from cooking to driving to running factories. Countries with smaller carbon footprints

use energy, too. T e biomass—wood, charcoal, dried plants, and animal dung—that people burn for cooking and heat also releases carbon dioxide. T eir energy use aff ects Earth, too.

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