Across
- 2. – the world around us: air, land, water, and living things
- 4. – use something again instead of throwing it away
- 5. – the variety of animals and plants on Earth
- 7. – when animals or plants disappear forever
- 9. warming – when the Earth becomes hotter
- 10. – too many people living in one place
Down
- 1. – keep something safe
- 3. – cutting down too many trees
- 6. – dirtying the air, water, or land
- 8. change – big changes in weather over a long time