Human intervention


Published on

this ppt is on the topic human intervention in nature

Published in: Technology, Business
  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Human intervention

  1. 1. Human Intervention
  2. 2. Why Are Trees Important To Us? What Is Deforestation? Its Causes And Effects. Ways To Preserve Forests. Causes And Effects Of Exhaustion Of Fossil Fuels. Ways To Preserve Fossil Fuels.
  3. 3. Why Are Trees Important To Us? Forests are a valuable natural resource. Some of the ways in which forests are beneficial to humans and environment: Forests provide habitat to a large number of plants, animals, birds and insects. Trees release oxygen, which is needed for survival. We obtain useful products such as timber, gum, paper and medicines from forests Roots of trees help to hold the soil in place, preventing land slides and soil erosion. Dead trees and plants decompose to form humus which helps in maintaining soil fertility.
  4. 4. Requirement of wood is one of the main of the main reasons trees are felled for. Wood is used as a fuel, for making furniture, in construction and for making paper, boats, rayon, etc. Overgrazing by animals is also a key factor that contributes to deforestation. Rapid Urbanization and increase I human population have led to conversion of forests to agricultural land. Forests have also been cleared for construction of roads, railway tracks, etc. What Is Deforestation? Its Causes. Rapid Urbanization and increase In human population have led to conversion of forests to agricultural land. Forests have also been cleared for construction of roads, railway tracks, etc.
  5. 5. Effects Of Deforestation Soil Erosion Destruction of the natural habitat of animals and birds Increase in global temperature Reduced rainfall Floods Landslides (in mountainous regions)
  6. 6. Main Effects Of Deforestation Roots of trees help in binding the soil particles together. When trees are destroyed soil is left loose and becomes prone to being eroded by moving water or wind. Forests are natural habitat of many species of animals and birds. Cutting down trees destroy the homes of these species, which poses a threat to their survival.
  7. 7. Main Effects Of Deforestation Due to the destruction of photosynthesis process the balance of oxygen in the air is disturbed. Increase in the concentration of carbon dioxide in the atmosphere may lead to an increase in global temperature. If a large number of trees are destroyed, overall transpiration rate will be greatly reduced. This can make the atmosphere drier lead to reduced rainfall.
  8. 8. Ways to Conserve our forests Some of the ways to conserve our forests are: Trees should be planted on a large scale on available land. Large-scale planting of saplings is called afforestation. When this done on deforested lands, it is called reforestation. More forest reserves and botanical gardens should be established. Allowing animals to graze on the same patch of land for a long period of time should be avoided. Measures should be taken to prevent and control forest fires. Awareness programs should be conducted by people to promote the need to use our forest resources judiciously. Since paper is obtained from wood pulp, recycling of paper will also help conserve trees to some extent.
  9. 9. Consequences of over-extraction of Fossil Fuels Some of the consequences of over extraction of fossil fuels are: Exhaustion of existing reserves Fossil fuels are a major part of the world today. The over-extraction of fossil fuels is slowly depleting the Earth of these resources. An energy crisis in the immediate future is a distinct possibility if the present rate of consumption of fossil fuels is not brought under control.
  10. 10. Consequences of over-extraction of Fossil Fuels Air Pollution When coal and petroleum products are burnt as fuels, they give off carbon dioxide, a greenhouse gas that leads to global warming. They also give off pollutants such as carbon monoxide, nitrogen oxides, and particulate matter such as mineral ash or fly ash, and unburnt hydrocarbons that pollute the air. Some of these gases combine with water vapour in air and form weak acids and fall on Earth as acid rain
  11. 11. Consequences of over-extraction of Fossil Fuels Threat to organisms Coal contains poisonous metals like arsenic and mercury, which are dangerous if released into the environment. If it settles in water and then enters the body of fish and shellfish then it can be harmful to people who eat them.
  12. 12. Ways to conserve Fossil fuels We cannot completely stop the use of fossil fuels. However, cutting down on their use and shifting to renewable energy sources will help us to conserve them as well as safeguard the environment. Some of the renewable sources of energy are discussed below. Wind energy has been used since ancient times to move ships, pump water, and grind corn. These days, huge wind turbines are used to drive generators.
  13. 13. Ways to conserve Fossil Fuels Hydroelectric energy is derived from the water in water bodies such as rivers with the help of dams and generators. Nuclear energy is released by the splitting or merging together of the nuclei of atoms. In nuclear power plants, this energy is utilized to produce heat energy, which is used to make steam for driving generators.
  14. 14. Ways to conserve Fossil Fuels Solar energy is utilized with the help of solar panels and solar cells. Solar panels convert solar energy into heat and light energy while solar cells convert it to electrical energy.
  15. 15. Made by -: VINEET AGGARWAL
  16. 16. THANK YOU