Across 2. the process of damaging the air, water, or land with chemicals or other substances 5. The relation of plants and living creatures to each other and to their environment; the study of this. 6. valuable substances such as wood and oil that exist in a country's land and sea (2 Words) 7. A long period of dry weather 12. The process of treating things that have already been used so that they can be used again. 13. waste food, paper, etc. that you throw away 15. a scientist who studies ecology 19. To add dirty or harmful substances to land, air, water, etc. so that it is no longer pleasant or safe to use. 25. Used water and waste substances that are produced by human bodies, that are carried away from houses and factories through special pipes. 27. Involving the use of natural products and energy in a way that does not harm the environment. (2 Words) 28. The mixture of gases that surrounds the earth. 29. A thick forest in tropical parts of the world that have a lot of rain. 30. That is replaced naturally or controlled carefully and can therefore be used without the risk of finishing it all.

Down 1. designed not to harm the areas in which we live (2 Words) 3. to prevent land, water, or other natural resources from being damaged or destroyed 4. rain that contains harmful chemicals from factory gases and that damages trees, crops and buildings (2 Words) 8. Things that you throw away because you no longer want or need them 9. of a type of plant, animal, etc.) no longer in existence 10. all the plants and living creatures in a particular area considered in relation to their physical environment 11. An area of oil that is floating on the surface of the ocean. (2 Words) 14. (used about groups of animals, plants, etc.) at risk of no longer existing (2 Words) 16. The process where radiation from a planet's atmosphere warms the planet's surface. (3 Words) 17. the act of cutting down or burning the trees in an area 18. changes in the earth's weather, including changes in temperature, wind patterns and rainfall, especially the increase in the temperature of the earth's atmosphere that is caused by the increase of particular gases, especially carbon dioxide (2 Words) 20. a gas breathed out by people and animals from the lungs or produced by burning carbon (2 Words) 21. substance that makes something impure 22. Fuel such as coal or oil, that was formed over millions of years from the remains of animals or plants. (2 Words) 23. Name for the rise in average temperature of the Earth's climate system and its related effects. (2 Words) 24. That cannot be replaced after use. 26. A region of Earth's stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation. (2 Words)