greenhouse gases

• human activity:

  • carbon dioxide:
  • deforestation -> less carbon dioxide removed through photosynthesis
  • burning fossil fuels releases carbon dioxide
  • methane:
  • more farm animals produce methane through digestion
  • waste from agriculture and landfill sites creates methane through decomposition
• • human activities increases temperature of Earth's atmosphere
  • this leads to climate change
  • evidence for this has been peer-reviewed
  • it is hard to understand the Earth's climate because of bias or oversimplifed models
• global climate change:

  • increase in global temperature leads to melting polar ice caps -> rise in sea levels, coastal erosion
  • change in rainfalls can cause droughts or floods -> change in ability for regions to produce food
  • increase in frequency and severity of storms
  • change in temperature and water available in habitat leads to change in distribution of species
• • greenhouse gases are carbon dioxide, methane and water
• • short wavelength radiation passes through atmosphere and some is reflected
  • short wavelength radiation absorbed by surface, increasing temperature
  • long wavelength radiation re-emitted
  • greenhouse gases absorb and re-emit long wavelength radiation
  • some long wavelength radiation absorbed by greenhouse gases and traps heat in atmosphere
  • temperature of Earth increases