Ecology
Endangered species
Affecting the environment
Wildlife
Rule of nature
100

Very close to the point at which something new, often something exciting or dangerous, is about to begin

On the brink of 

100

Used especially of plants and animals which are danger of being made extinct 

Endangered 

100

The act or process of causing something 

Pollution 

100

The natural surroundings in which a plant or animal usually lives 

Habitat

100

To control something by the use of rules

Regulate

200

The cutting down or burning of trees 

Deforestation 

200

The making extinct of something 

Extinction 

200

A chemical substance that is used to kill pests 

Pesticide 

200

To kill it destroy completely 

Wipe out 

200

To change something completely so that it's the opposite of what it was 

Reverse 

300

The relationship between human, animal and plant life 

Ecology 

300

No longer existing 

Extinct 

300

To cause something to be dirty 

Pollute

300

On a large scale, affecting a great many people or things 

Wholesale 

300

To destroy somewhere completely 

Lay waste to

400

Relating to ecology or to the environment 

Ecological 

400

The gradual development, especially of living things 

Evolution 

400

Poisonous substance 

Toxin

400

To continue to live or exist 

Survive

400

A group into which animals or plants are divided 

Soecies

500

All the living creatures and plants in a particular area 

Ecosystem 

500

Connected with evolution 

Evolutionary 

500

Animals, birds and insects which live in their natural surroundings 

Wildlife 

500

The act or state of surviving 

Survival 

500

Official rule

Regulation