UNIT 5 GLOBAL WARMING

the cutting down of trees in a large area, or the destruction of forests by people

that can be replaced naturally without being used up

a substance that pollutes

a substance that was formed millions of years ago from dead animals or plants.

gases or other substances that are sent into the atmosphere

to let a substance flow out

a black rock that is found under the ground and is burnt to produce heat

a situation in which different things are equal

the increase in the earth’s temperature because of certain gases in the atmosphere.

materials that are not needed and are thrown away