Ever since the Industrial Revolution, the world has been hungry for energy. A hundred years ago, developing technologies relied on fossil fuels—and that reliance has only grown with time. Today, most power plants burn coal, oil, or natural gas; cars run on oceans of gasoline; and people heat their homes with oil or gas. But fossil fuels won’t last forever, and their overuse poses serious environmental problems. We need new technologies to supply our energy without taking such a heavy toll on the planet.
There are lots of reasons to be optimistic about the future. We’re at an exciting and historic crossroads: Conventional power sources such as fossil fuels are making room for carbon-neutral, earth-friendly alternatives. This chapter gives an overview of renewable energy and some of the emerging technologies.
As you’ve no doubt heard, the climate is changing—largely due to human activity. Global warming refers to an average increase in the temperature on the earth’s surface and in the troposphere, the atmosphere’s lowest layer. This warming contributes to climate changes, which can have a host of consequences, like shrinking polar ice caps, rising sea levels, and changes in weather patterns that can affect crops and even drive some species to extinction.
A big cause of global warming are the greenhouses gases that get released when people burn fossil fuels like coal, petroleum, and natural gas. These gases—which ...