Our climate and weather are changing – both globally and regionally – because of increasing levels of “greenhouse gases” (GHGs) in our atmosphere. Some of these gases occur naturally, but recent increases are resulting from human activity. In our atmosphere, GHGs trap heat, like a greenhouse. While this effect is essential for life, levels of GHGs that far exceed natural levels are causing global temperatures to rise. Regionally and locally, we are experiencing warmer weather and rising sea levels. In the years ahead, we are likely to be affected by more intense storms, droughts and floods.

GHGs include:
 

  • Carbon Dioxide (CO2): This gas is a product of natural processes, such as animal respiration, and human activities that burn fossil fuels and deforest natural areas. While it is an essential component of our atmosphere, human activities are driving the CO2 concentrations in our atmosphere far above natural levels. While much less potent than other greenhouse gases on a per-ton basis, carbon dioxide is the most important greenhouse gas because it is emitted in much greater quantities than the other gases listed below. 
  • Methane (CH4): The primary ingredient of natural gas, methane can leak during production and transmission. It is also a by-product of coal mining and oil drilling operations. Other important sources of methane include livestock and the decay of organic material in landfills and wastewater treatment. In the atmosphere, methane is a potent contributor to global warming.
  • Nitrous Oxide (N2O): This gas is produced by agricultural activities, fossil fuel combustion, and industry. Like methane, nitrous oxide is a potent greenhouse gas. 
  • Fluorinated Gases: These gases – particularly hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride – are synthetic gases that are used widely in refrigeration systems, high-voltage electrical equipment, and semiconductor manufacturing. While leaks from this equipment are likely to be small individually, collectively they contribute significantly to increasing GHG levels in the atmosphere because many of these gases are extremely potent contributors to global warming.