18.3

• Climate


  The average condition of the atmosphere at a certain place over a long period of time
• Climate


  The weather of a specific region averaged over a long period of time
• Causes of climate


  • Sun's solar energy
  • Angular position of Earth relative to Sun
  • Wind and ocean current patterns
  • Bodies of water surrounding an area
  • Altitude of an area
• The Earth's climate system depends entirely on the sun for its energy
• Solar radiation warms the atmosphere and is fundamental to atmospheric composition while the distribution of solar heating across the planet produces global wind patterns and contributes to the formation of clouds, storms and rainfall
• Seasons


  Caused by Earth's tilted axis, with different parts of the Earth receiving the Sun's most direct rays at different times of the year
• Bodies of water


  Can affect the climate of an area, as water heats and cools more slowly than landmasses, creating a more moderate climate with a warmer temperature range in coastal regions
• Altitude


  As elevation increases, the climate becomes harsher with more intense weathering, colder temperatures and stronger winds
• Wind and ocean currents


  Carry moisture, hot and cold air into a climate, affecting weather patterns
• Climate change


  The long-term shift in temperature and weather patterns, which may be natural but since the 1800s has been mainly driven by human activities like burning of fossil fuels
• Ice Age


  A geologic period when thick ice sheets cover vast areas of land
• Global warming


  The period of global temperature increase, caused by the atmosphere trapping more heat due to increasing greenhouse gases
• January 2000 to December 2009 is the warmest decade on record in the past 130 years
• Effects of global warming


  • Drastic changes in weather patterns
  • Stronger typhoons/hurricanes
  • Rain falling in different areas with no definitive pattern
• Weather patterns are shifting, with some areas having less rainfall and suffering droughts, while others experience higher than usual rainfall
• As the Earth warms, rainfall patterns are modified, growing seasons are changed and storms and floods are becoming more severe
• As the world warms, hurricanes and other tropical cyclones should get stronger because warmer water provides more energy to fuel these storms
• Climate change is disrupting weather patterns, leading to extreme weather events, unpredictable water availability, exacerbating water scarcity and contaminating water supplies
• Effects of global warming

  • Ice cap melting
  • Destruction of polar habitats like that of polar bears
  • Rising sea levels leading to coastal erosion and more frequent/intense coastal storms
• Polar bears have now been classified as an endangered species due to ongoing and potential loss of their sea ice habitat resulting from climate change
• Floods are more likely due to the more extreme weather patterns caused by long-term global climate change
• Other effects of global warming


  • Forests more vulnerable to fire and infestations
  • Increased risks of heat stroke and skin cancer from intense heat waves and UV rays
• Greenhouse


  A structure with glass walls, doors, and roof used to grow plants by trapping heat from the sun
• Greenhouse effect


  The process where gases in Earth's atmosphere trap the sun's heat, making Earth much warmer than it would be without an atmosphere
• The greenhouse effect helps maintain a certain temperature level on Earth's surface, making it habitable for living things
• Albedo


  The measure of the reflectivity of a surface, affecting how much heat is absorbed or reflected by the Earth's surface
• Greenhouse gases


  • Carbon dioxide
  • Methane
  • Nitrous oxide
  • Ozone
  • Chlorofluorocarbons
• Carbon dioxide


  Increased levels caused by burning of fossil fuels, cement production, and deforestation, with more produced than consumed
• Methane


  A powerful greenhouse gas produced from fuel production, landfills, mining, and agricultural wastes, with large amounts stored in melting ice caps
• Ozone


  Responsible for blocking harmful ultraviolet radiation, but its depletion is caused by the greenhouse gas CFC
• Chlorofluorocarbons (CFCs)


  Major sources include refrigerators, air conditioners, solvents, aerosols, and plastics, and they destroy the ozone layer
• Nitrous oxide


  A potent greenhouse gas 300 times more powerful than carbon dioxide, produced from burning fossil fuels and agricultural processes, which may also destroy the ozone layer
• Global greenhouse gas emissions come from a variety of sources