Unit 4

• Environment


  Any living or non-living factor that has an influence on living organisms
• The term environment usually refers to an organism's surroundings
• We can talk about the classroom environment, which means all the living and non-living things that are in the classroom
• Humans have had the ability to change the natural environment for thousands of years
• The environment in nearly every ecosystem has been changed by human activities
• Human activities that affect the environment

  • Air pollution and global warming
  • Agriculture
  • Industry and urbanisation
  • Human population growth
  • Poaching
• Burning of fossil fuels such as coal and oil


  Contributes largely to global warming, which is speeding up climate change
• Global average temperatures have increased by 0.6 °C over the last 100 years
• A change in average temperatures


  Will change habitats and affect rainfall patterns
• Many species will be unable to survive in these new conditions
• In order to grow crops to feed the growing population, more and more land has to be cultivated
• Natural habitats are destroyed in the process of agriculture
• Water is needed for irrigation, which threatens freshwater habitats
• Use of fertilisers in agriculture can pollute water bodies and damage the soil
• As towns and cities develop around industries, natural vegetation must be cleared to build factories, roads, houses, and amenities
• These actions destroy the habitats of plants and animals
• Pollution from factories can damage habitats
• Many frog and fish species are unable to live in polluted water
• Many human activities resulting from the population explosion are harming the environment
• Humans are using more and more energy, land, water, and other natural resources
• Increased population growth leads to more pollution of the water, air, and land
• Poaching is the illegal catching and killing of animals
• Heavy poaching can lead to the extinction or collapse of certain species of animals
• In South Africa, abalone (perlemoen) are almost extinct owing to poaching
• Both white and black rhinos are poached for their horns
• As a result, these two species are now also facing extinction
• Poaching


  The illegal catching and killing of animals
• Extinction


  The death of all individuals of a species