Environment - Natural World

1. Desertification is when land turns to desert, meaning that little, or no, food can be grown.

2. Desertification is caused by lower rainfall and higher temperatures because of deforestation.

3. Animals overgrazing may also lead to desertification, as they remove the vegetation and leave the soil exposed.

4. One of the main causes of desertification is too many people living in an area.

5. A direct result of desertification is an increase in the number of dust and sand storms and floods.

6. These remove topsoil and soil nutrients needed for food production and plant growth that leads to a reduction in carbon dioxide.

7. The world’s population is increasing so there is pressure to produce more and more food.

8. Intensive farming means using chemicals and technology to get the most out of the land.

9. The soil can become less fertile due to overuse, so more artificial fertiliser is used.

10. When the fertiliser is washed away by rain, it can pollute the rivers.

11. It is now common to rely on just one type of crop.

12. This can lead to crop failures and poor harvests because pests and disease thrive in an environment full of one particular plant.

13. This means that farmers have to use more pesticides to protect the crop.

14. The removal of hedges to create larger areas to farm has led to soil erosion and the loss of habitat for wildlife.

15. Soil erosion is when soil is blown away by the wind or washed away by the rain.

16. Plants and trees bind the soil together and stop this happening.

17. Soil erosion occurs in areas with steep slopes or where trees or hedges have been cut down.

18. Soil erosion also occurs in droughts, when vegetation grows poorly, and in overpopulated rural areas.

19. Soil erosion removes the topsoil which is rich in nutrients.

20. Planting trees to bind the soil together and provide windbreaks can help to prevent it

21. Developing irrigation schemes in areas of drought also helps.

22. Keeping the soil as rich in nutrients as possible and rotating crops

23. If soil erosion is allowed to continue, it can result in the formation of deserts.

24. The demand for fresh water is growing as the population of the world rises.

25. Water is needed for household use, agriculture and industry.

26. The more water that humans use, the less there is available for marshes, wetlands and rivers and the species they support.

27. Two-thirds of the world’s population lives in areas receiving only one quarter of the world’s annual rainfall.

28. Many countries in the developing world get 90% of their water during the monsoon period.

29. The rest of the time they have virtually none.

30. The monsoon rains run off too quickly for efficient use.

31. Pollution of rivers and lakes further reduces the available freshwater supplies.

32. Some countries are now facing severe water shortages.

33. Volcanic eruptions send huge clouds of sulphur dioxide gas into the atmosphere.

34. These can lower the temperature and cause global cooling.

35. Eruptions can have a severe effect on the weather, which can lead to crop failures and unseasonal conditions.

36. Volcanic gases can destroy ozone.