GLOBAL SYSTEMS

5. Period of milder climate between two glacial periods.
8. A substance that can be replaced and is of economic value.
9. Soil that remains bellow the freezing point of water for two or more years.
10. Our living world.
13. Circulation in the Pacific which depends upon conjoint effect of temperature and salinity.
16. Natural fuel formed millions of years ago from the remains of living organisms e.g coal
17. Naturally occurring chemical compound.
18. All the living organisms existing together in a particular area .
20. A layer of gases surrounding the Earth
23. Layer of ice covering extensive tract of land for a long period of time.
24. A measure of the average temperature, humidity, wind, precipitation and meteorological patterns.
25. Gases and other particles released into the atmosphere by burning fuels.

1. Form of light we cannot see but can feel as heat.
2. Colorless, odorless, flammable chemical compound found throughout the earth.
3. The changing of water vapor back into liquid state and forming clouds by using cold temperatures.
4. All the waters on the earths surface.
6. effect The trapping of the sun's warmth.
7. Plants and other organisms convert the suns light to energy.
11. Parts of the radio spectrum with relatively long wavelengths.
12. The clearing of natural trees in forest areas.
14. Outer part of earth, consists of crust and upper mantle.
15. Effects the global climate, warm water in the pacific.
17. the process in which carbon is recycled.
19. A energy type derived from renewable plant and animal materials.
21. Energy that comes from a source which is able to penetrate various materials e.g light, radio microwaves.
22. Nonreactive gas that forms about 78% of the earth's atmosphere.