Across
- 1. One of the layers of the atmosphere
- 3. The best quality coal
- 6. Contamination of air, water and soil
- 7. A secondary pollutant
- 8. Unit of sound intensity
- 10. It is the unwanted sound
- 12. Gradual increase in the temperature of earth's surface
- 13. Another word for poisonous
- 15. Burning of waste at high temperature
- 16. Downward curling of leaves
- 17. Fuels like petroleum, coal and natural gas
- 19. Permanent clearance of forest areas
- 20. Main culprit for ozone layer depletion
Down
- 2. It is commonly known as liquid gold
- 4. Largest contributor to global warming
- 5. It is called black gold
- 9. Combination of Smoke and Fog
- 11. Variety and variability of life on Earth
- 14. Seriously under threat of extinction
- 18. Process of minimizing waste by transforming them into new products