greenhouse gases - c13

• What is often true about media reports on global warming?

  They are often biased or over-simplified
• What are the main greenhouse gases in our atmosphere?

  Carbon dioxide, methane, and water vapour
• Why is CO₂ crucial for life on Earth?


  Earth would be -19°C without it
• What percentage of the sun's energy is reflected back into space?


  Almost 30%
• What type of radiation do greenhouse gases allow to pass through?


  Short wave radiation (e.g. ultraviolet)
• How does Earth cool itself?


  By emitting long wave infrared radiation
• What do greenhouse gases do to infrared radiation?


  They absorb it
• What effect does absorbed radiation have on molecules?


  It makes bonds in molecules vibrate and stretch more
• What happens to long wave radiation in the atmosphere?


  Some is trapped, increasing the temperature
• How does the proportion of greenhouse gases affect energy absorption?

  The higher the proportion, the more energy is absorbed
• How has CO₂ release changed in the last century?


  It has greatly increased
• What is a major reason for the increase in CO₂ levels?


  More fossil fuels are used to make electricity, heat homes, and run cars
• What happens to carbon locked in fossil fuels when burned?


  It is released as CO₂
• What is the chemical reaction for propane combustion?


  $C_3H_8 +$$5O_2 \rightarrow 3CO_2 +$$4H_2O$
• Where is methane released from?


  Swamps, rice fields, grazing cattle, and landfill sites
• Which greenhouse gas has had the biggest increase?


  Carbon dioxide
• What effect are living organisms experiencing due to greenhouse gases?

  They are experiencing an enhanced greenhouse effect
• What are the key points about greenhouse gases and their effects?

  • Greenhouse gases include CO₂, methane, and water vapour.
  • They absorb infrared radiation and trap heat in the atmosphere.
  • Increased levels of greenhouse gases lead to higher temperatures.
  • CO₂ levels have significantly increased due to fossil fuel combustion.
  • Methane is released from various sources, including agriculture and landfills.