Across
- 5. biomass produced in past ages
- 6. variation in the state of the climate system
- 8. convert waste into new products
- 9. the introduction of substances into a medium that can cause this marine insecure
- 10. environmental indicator
- 11. is the simplest alkane hydrocarbon
- 12. is the disappearance of all members of a species
Down
- 1. internal energy of a body
- 2. energy from natural sources
- 3. caused by overflowing rivers, torrential rains, hurricanes and tidal waves
- 4. is a mixture of organic substances
- 7. natural environment encompasses all living and non-living