Changes in Climate

Changes in Climate

ESS. 15 Fluid Eart. The student knows that interactions among Earth's five subsystems influence habitability. 

Types of Energy Resources

There are two basic types of energy resources. Like other natural resources, energy resources are either nonrenewable or renewable.

Nonrenewable resources are natural resources that either cannot be replaced at all or cannot be replaced as quickly as they are used.

Fossil fuels—coal, oil, and natural gas—are the major nonrenewable energy resources used today. They form from the partially decomposed remains of once-living organisms. Fossil fuels take millions of years to form, far too long to be replaced as quickly as we use them. The use of fossil fuels also has adverse effects on the environment.

When fossil fuels are burned, they release pollutants into the atmosphere that can harm human health and the health of ecosystems. The burning of fossil fuels also releases carbon dioxide and other greenhouse gases, which are causing global temperatures to rise.

Renewable resources are natural resources that either are virtually limitless or can be replaced as quickly as they are used. The sun will continue to provide us with solar energy for billions of years.

Flowing water and wind will always be abundant. Sources of biomass energy, such as trees, can be replaced relatively quickly. Unlike the use of fossil fuels, the use of most renewable energy resources does not produce pollutants or carbon dioxide. However, some renewable energy resources can cause environmental problems. For example, damming streams to capture energy from flowing water can harm ecosystems. Some renewable energy resources are currently expensive to use. Some are needed for other uses in addition to energy. For example, trees are needed for lumber in addition to fuel.