Across
- 4. – something that is worth a lot or very important
- 5. fuel – energy sources like coal, oil, and gas formed from ancient plants
- 8. warming – the Earth’s temperature getting higher because of pollution
- 11. – the act of sending gases or smoke into the air
- 13. – not harmful to the environment
- 14. – when a species disappears completely from the earth
- 15. growth – when the number of people in an area increases
Down
- 1. gas – a gas that traps heat in the atmosphere, like CO₂
- 2. change – long-term change in the Earth’s temperature and weather
- 3. – cutting down too many trees in a forest
- 6. – a group of animals or plants that are similar and can reproduce
- 7. – reusing materials instead of throwing them away
- 9. – farm animals like cows, pigs, and sheep
- 10. – the habit of buying and using lots of goods and products
- 12. – harmful substances in the air, water, or soil