Causes of climate change

• Climate


  The average conditions of the atmosphere in a large region over decades or more, including clouds, precipitation, temperature, humidity, atmospheric pressure, solar radiation, and wind
• Climate


  • Can refer to large and small regions - BC has a range of different climate zones
  • Each region has certain types of plants, animals, ecosystems, and resources
• Climate


  The weather of a place averaged over a period of time, including normal weather and the range of weather extremes
• Weather


  The day-to-day state of the atmosphere, and its short-term variation in minutes to weeks

  
• Determining the past climate

  1. Studying fossils and sediments

  2. Gathering information about ice

  
• Ice cores are used to determine what types and amounts of gases existed in the atmosphere when the ice was formed
• Geologic evidence shows that, throughout its history, Earth has undergone major climatic changes, including ice ages and periods of warming
• Scientists draw conclusions about current climatic changes by observing present climate and by comparing their observations with evidence of past climates

  
• What effects climate


  • Composition of Earth's atmosphere
  • Earth's tilt, axis of rotation, and orbit around Sun
  • The water cycle
  • Ocean currents
  • The carbon cycle
  • Catastrophic events

  
• Climate change


  Changes in long-term weather patterns in certain regions that affect the redistribution of thermal energy around Earth
• Global warming


  An increase in Earth's average global temperature, which is one aspect of climate change

  
• Greenhouse effect


  The ability of the atmosphere to absorb and emit more thermal energy as greenhouse gases increase

  
• Global warming potential (GWP)


  The ability of a substance to warm the atmosphere by absorbing and emitting thermal energy

  
• General circulation models (GCMs)

  Computer models designed to study climate, taking into account multiple factors such as changes in greenhouse gas concentrations, ocean currents, winds, surface temperatures, and albedo

  
• The albedo at Earth's surface affects the amount of solar radiation that a region receives

  
• GCMs can determine both past and present climate, and some models predict a temperature rise of 6°C in northern regions and a sea level rise of almost 88 cm within the next 100 years

  
• Climate change is more extreme in developing countries
• How the Sun heats the Earth

  1. Sun's rays radiate heat towards the Earth

  2. Rays reflect off the surface of the Earth, with some heat trapped by the atmosphere and some reflected back into space

  3. Light surfaces on Earth absorb heat

  4. Dark surfaces on Earth absorb heat

  
• There are more greenhouse gases in the Earth's atmosphere than ever before, and these gases trap more heat in the atmosphere

  
• In Earth's history, there was usually 220-228ppm of CO2, but due to human emissions, there is currently 415ppm

  
• Temperatures have risen approximately 1 degree Celsius since industrial times
• What Canada is doing about climate change

  • Investing in energy-efficient housing, model codes for new and existing buildings
  • Investing in clean transportation, more electric vehicle charging stations, developing stringent vehicle standards, cleaner fuels
  • Investing in clean electricity, pricing industrial emissions, reducing methane in the oil and gas sector
  • Supporting clean agriculture and bioproducts, conserving more nature for carbon sequestration, reforestation, reducing waste including plastic pollution
  • Phasing out coal-fired electricity, increasing investment in renewable energy, increasing investment in smart grids