Greenhouse Gases

• A gas that releases and absorbs radiation and keep heat inside the Earth’s atmosphere
• Mainly released by the burning of fossil fuels
• The IPPC has confirmed increased levels of greenhouse gases in the atmosphere
• Water Vapour
• Most common of all greenhouse gases
• Largest contributor to the greenhouse effect
• Carbon Dioxide (CO2)
• Majority released due to fossil fuel use in transportations, heating/cooling, etc,...
• Reduced quantities of carbon sinks due to deforestation reduces the amount of CO2 that can be uptaken by plants
• Released naturally by decaying plant matter
• Stay in atmosphere for 50-200 years average
• Methane (CH4)
• Increased due to agriculture, natural gas distribution, landfills
• Released naturally from wetlands
• 60% is human released
• Stay in atmosphere for 12 years on average
• Nitrous Oxide (N2O)
• Released by fertilizer use, fossil fuel burning, wastewater management
• Stay in the atmosphere for 120 years on average
• Halocarbons (HFCs, PFCs, SF6)
• Most potent and long lasting gas released by human activity
• Lifespan
• HFH: 1-270 years
• PFC: 800-50000 years
• SF6: 3200 years
• Used as a coolant (eg. Air conditioners, refrigerators)

Why are these important?

These gases, mainly released by human activity, contribute to global climate change.  This natural occurrence uses greenhouse gases to trap thermal energy from the Sun inside Earth’s atmosphere.  With an increased amount of these gases, the amount of heat retained in the Earth’s atmosphere is growing.