1. subconscious
1.1. Religion
1.1.1. belief
2. Animals
2.1. web of life
2.1.1. herd
2.2. biodiversity
2.2.1. balance
2.3. collectivization
2.3.1. maternal instinct
2.3.1.1. idealistic
2.4. exotics
2.4.1. trade
2.4.1.1. mortality
2.5. extinction
2.5.1. endagered
2.5.1.1. otter
2.6. food chain
2.6.1. predator
2.7. research
2.7.1. application
2.7.1.1. anastomosis
2.8. spontaneous
2.8.1. instinct
2.8.1.1. sentiment
3. Global warming
3.1. climate
3.1.1. atmosphere
3.1.1.1. temperature
3.1.1.1.1. onaon layer
3.2. ozone depletion
3.2.1. Trioxygen
3.2.1.1. molecule
3.3. Polar Regions
3.3.1. dissolve
4. energy
4.1. carbon dioxide
4.1.1. melt
4.1.1.1. glacier
4.2. Eco-friendly energy
4.2.1. climate
4.2.1.1. Greenhouse gas
4.2.1.1.1. carbon dioxide
4.2.1.1.2. methane
4.2.1.2. Fossil fuel
4.2.1.2.1. unleaded petrol
4.2.1.3. ozone layer
4.3. limited energy
4.4. deplete
4.5. enlightened
4.5.1. Revolution
4.5.1.1. free will
5. Waste
5.1. decomposition
5.1.1. microorganism
5.2. disposal
5.2.1. air polluion
5.2.1.1. water pollution
5.2.1.1.1. land pollution
5.3. landfill
5.4. overspending
5.4.1. scrap
6. Ocean
6.1. Pacific plastic land
6.1.1. marin community
6.1.1.1. aquatic ecosystem
6.1.2. microplastic
6.2. Blanching
6.2.1. oceanic acidification
6.2.1.1. declining populations
7. recycle
7.1. radioactive materials
7.1.1. compound
7.2. Recycling reform
7.2.1. utility
8. Water
8.1. water deficit
8.1.1. Water Stress
8.1.1.1. South Africa
8.1.1.2. Egypt
8.2. hydroelectric power
8.2.1. a power plant
8.2.1.1. thermal power
8.2.1.2. tidal power
8.2.1.3. nuclear energy
9. Forest
9.1. deforestation
9.1.1. habitat destruction
9.2. rainforest
9.3. tree species richness
9.3.1. oak
9.4. overgrown
9.4.1. overgrowth
10. Food
10.1. agriculture chemicals
10.1.1. worm
10.1.2. insecticide
10.2. catch quota
10.3. food of the future
10.3.1. grasshopper
10.3.2. cricket
10.3.3. insect
10.4. slow food
10.5. cereal
10.5.1. barley
10.6. greens
10.6.1. lettuce
10.6.2. perilla leaf