• human activities have minimal impact on climate
  • warming is caused by natural phenomena
    • natural factors aren't enough to explain warming
• human activities are causing global warming
  • greenhouse gases cause global warming
  • greenhouse gas levels are rising sharply
    • CO2 measurements are not reliable
      • CO2 levels are measured by hundreds of stations
  • greenhouse gases increases are due to human activity
    • human CO2 emissions are negligible
      • Human emissions are not balanced by natural absorptions
    • CO2 is coming from natural sources (e.g. ocean)
      • CO2 is due to the burning of fossil fuels
  • the scientific community has broad consensus on this