8th Class General Science: Ecology and Pollution

General Science Notes for 8th Class (For Islamabad)

Unit 1: Ecology

Control of Pollution

• Pollution is the addition of harmful substances in the environment
• Unjustified use of resources has damaged the environment drastically
• Major pollution causing substances include:
  • Harmful gases and dust from factories
  • Pollutants from power stations and automobiles
  • Sewage from urban areas
  • Use of plastics
• Air and water pollution has badly affected all forms of life
• Conservation efforts can help conserve endangered species

Control of Air Pollution

• Shift to clean energy sources can reduce air pollution and reverse its effect on the environment
• Use of wind power stations and solar energy is replacing coal and oil power stations
• Electrical vehicles are becoming popular day by day

Control of Water Pollution

• Protection of clean water resources is a challenge
• Water conservation, treatment of sewage from homes and industry, and less use of plastic can control water pollution
• This will make more clean water available to keep the ecosystem flourishing

Conservation of Endangered Species

• Plants and animals maintain the health of an ecosystem
• When a species becomes endangered, it is a sign that the ecosystem is out of balance
• Governments, NGOs, local communities, and individuals work together to conserve endangered species
• Awareness campaigns can get more people involved in conservation work

Endangered Species: Pangolin

Blind Indus Dolphin

• Blind Indus dolphin is endemic to river Indus and cannot survive in sea water
• Factors leading to its threat of extinction include:
  • Pollution of river water by human activities
  • Scarcity of feeding material
• The Indus River Dolphin is listed as endangered on the IUCN Red List of Threatened species
• Only about 1100 Indus River Dolphin exist in the world

Conservation of Indus Dolphin

• Steps to help conservation include:
  • Starting a Dolphin Rescue Program
  • Controlling illegal hunting and over-night netting
  • Controlling the use of poisonous pesticides
  • Rescuing dolphins trapped in shallow water
  • Protecting dolphin habitats

Global Warming

• Global warming can cause ice to melt on mountains, increasing sea levels and threatening islands less than one meter above sea level
• Ways to save coastal cities from flooding or being submerged include:
  • Combating global warming
  • Reducing the production of CO2
  • Making more dams
  • Growing more trees