It is a mixture of solid particles and gases in the air.
air pollution
10
A gradual increase in world temperatures caused by gases such as carbon dioxide that are collecting in the air around the earth and stopping heat escaping into space
Global Warming
15
A long period when there is little or no rain
Drought.
15
Able to decay naturally and in a way that is not harmful
Biodegradable
15
The process of getting rid of large amounts of rubbish by burying it, or a place where rubbish is buried
Landfill
15
Substances that are used in or produced by a reaction involving changes to atoms or molecules and are harmful for health.
Toxic Chemicals
15
Relating to products, systems, etc. that use as little electricity, gas, etc. as possible
energy-saving
15
Not harmful to the environment
Environmentally-friendly.
15
Things such as minerals, forests, coal, etc. that exist in a place and can be used by people