Global Warming & Climate Change

• Global warming


  The increase in the Earth's average surface temperature due to the greenhouse effect
• Climate change


  The long-term changes in weather patterns across the entire planet
• Greenhouse effect


  1. Sun's heat energy passes through atmosphere

  2. Some energy absorbed by Earth's surface

  3. Most energy re-emitted as longer wavelength radiation

  4. Greenhouse gases absorb and re-emit this energy in random directions

  5. Heat energy stays close to Earth
• Greenhouse gases


  • Carbon dioxide
  • Methane
  • Water vapor
• Increasing greenhouse gas concentrations

  Stronger greenhouse effect and global warming
• Causes of increasing carbon dioxide levels

  • Burning of fossil fuels
  • Deforestation
• Causes of increasing methane levels

  • Emissions from farm animals
  • Decomposition of waste
• Earth's temperature records show steady increase over hundreds of years
• Consequences of global warming are hard to model due to many variables
• Global warming


  Leads to climate change
• Consequences of climate change

  • More common and severe droughts, hurricanes, floods
  • Sea level rise due to ice melt and water expansion
  • Impacts on biodiversity and species survival