Enhanced Greenhouse Effect (Edexcel IGCSE Biology: Double Science)

• The greenhouse effect describes the following process:
  • the Sun emits rays that enter the Earth’s atmosphere
  • heat bounces back from the Earth’s surface
  • some heat is reflected back out into space
  • some heat is absorbed by greenhouse gases and is trapped within the Earth’s atmosphere – this is normal

• The enhanced greenhouse effect happens when increasing levels of greenhouse gases from human activities cause the Earth's average temperature to rise above normal, leading to global warming

How the greenhouse effect works

The consequences of global warming

• The consequences of global warming due to an enhanced greenhouse effect include:
  • Ocean temperatures increasing, causing melting of polar ice caps / rising sea levels / flooding / coral bleaching
  • Increasing temperatures causing extreme weather like super storms, flooding, droughts
  • Changes in or loss of habitats due to these extreme weather events
  • Decreases in biodiversity as food chains are disrupted and extinction rates increase
  • Increases in migration of species to new places, including increased spread of pests and disease