Natural Resource A material found in nature that people use. (These resources can be processed, but occur naturally.) They help us meet our needs. Sand Coal Trees Renewable Resource A material that, with careful planning, can be replaced or replenished after use. Trees Nonrenewable Resource A material that cannot be replaced after use. Coal Pollute To harm Earth’s land, air, or water by making it dirty. Mineral Something that comes from the Earth and is removed by mining. Limestone Diamond Gold Fossil Fuel Fuel formed in the earth from ancient plant and animal remains. Oil Coal Natural Gas Erosion The wearing away of soil by water and wind. Runoff When the water runs across hard surfaces collecting oil, dirt, and pollutants. It can then flow into a river and pollute the water. Conserve To keep something from becoming damaged or lost.