THE ENVIRONMENT

1. Use of renewable resources

1.1. sun

1.2. wind

1.3. heat of the earth

2. PROBLEMS

2.1. Pollution

2.1.1. Air pollution

2.1.2. Water pollution

2.1.3. Light pollution

2.1.4. By waste

2.2. Global warming

2.3. Growing population

2.4. Endangered species

3. Solutions

3.1. Recycling

3.2. Green transport