Energy Technologies

In 1900, coal accounted for about half of the global energy consumed. As extraction, refinement, and transportation technologies allowed for widespread use, petroleum, also known as crude oil, and natural gas joined coal in fueling industrial output and helped increase productivity. Research in the 1930s and 1940s that led to the atomic bomb also led to the first use of nuclear power plants to generate electricity for factories and homes.

Fossil fuels—coal, petroleum, and natural gas—are nonrenewable resources. Once they have been used up, the supply is permanently depleted. Fossil fuels have contributed to air pollution and to the cloak of greenhouse gases, especially carbon dioxide, that allow sunlight through the Earth’s atmosphere but block the escape of Earth’s heat. Nuclear power, while considered a clean energy, has its own dangers. Accidents at nuclear plants have caused serious problems with leaked radiation, and storing nuclear waste has hazardous consequences.

Technologies continue to be developed to combat the emission of carbon dioxide and other greenhouse gases as well as minimize harm from nuclear power. The building of nuclear power plants declined starting in the 1980s, and nuclear power accounts for only about 5 percent of global energy consumption. Renewable resources, such as wind and solar power, are beginning to supply energy to both industries and homes, but they too represent only 5 percent of global energy output. (Connect: Analyze the role of various energy sources in the first and second industrial revolutions and in the 21st century. See Topic 5.5.)