Desertification: the process by which land changes into desert, for example because there has been too much farming activity on it or because a lot of trees have been cut down
Noun: Trees help to prevent desertification, as well as providing shade and firewood.
country: an area of land that has its own government, army, etc.
Noun: What is the largest country in Europe?
Air pollution: harmful substances in the air, often consisting of waste from vehicles or industry
Noun: Diesel exhaust is a major contributor to air pollution.
Endangered species: a type of animal or plant that might stop existing because there are only a few of that type alive
Noun: The bald eagle is no longer an endangered species
expanding: to increase in size, number, or importance, or to make something increase in this way
Noun: The air in the balloon expands when heated.
flooding: a situation in which an area is covered with water, especially from rain
Noun: Some roads have been closed because of flooding.
solid waste: Material such as household trash, food waste, yard waste, construction debris, scrap metal and so on.
Noun: Solid waste is disposed of in a landfill.
alternatives: An alternative plan or method is one that you can use if you do not want to use another one
Noun: The opposition parties have so far failed to set out an alternative strategy.
fossil fuel: fuels, such as gas, coal, and oil, that were formed underground from plant and animal remains millions of years ago
Noun: Burning fossil fuels releases harmful gases
effect: the result of a particular influence
Noun: The radiation leak has had a disastrous effect on/upon the environment.
Endangered species: a type of animal or plant that might stop existing because there are only a few of that type alive
Noun: The bald eagle is no longer an endangered species
deserts: a person's worthiness or entitlement to reward or punishment.
Noun: in the desert there is not so much water
untreated sewage: Sewage that has not been processed to remove contaminats.
Noun: The bay was polluted with untreated sewage.
global warming: 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
Noun: The destruction of the rainforests is contributing to global warming.
overfishing: catching too many fish in an area of the sea, so that there are not many fish left there
Noun: low fish stocks caused by overfishing
Coastal flooding: When dry, low-lying land is flooded by seawater
Noun: Coastal flooding will affect millions of people if sea levels rise.
Acid rain: rain that contains large amounts of harmful chemicals as a result of burning substances such as coal and oil
Noun: acid rain is dangerous
Climate change: changes in the world's weather, in particular the fact that it is believed to be getting warmer as a result of human activity increasing the level of carbon dioxide in the atmosphere
Noun: The President called for urgent action on climate change.
planet: an extremely large, round mass of rock and metal, such as Earth, or of gas, such as Jupiter, that moves in a circular path around the sun or another star.
Noun: Might there be intelligent life on other planets?
greenhouse gas: a gas that causes the greenhouse effect, especially carbon dioxide
Noun: greenhouse gases include water vapor, carbon dioxide and methane