Climate change

Climate change

1. Global warming

   • Causes of Global Warming
     • Greenhouse effect
       • definitions
         • greenhouse gas + water vapour + dust
           • trap heat
             • keep earth's surface warm
       • causes of greenhouse effect
         • more farming activities
           • rapid grow of population
             • need food
               • grow more rice + rear more livestock
                 • release methane
         • burning of fossil fuels
           • emits carbon dioxide
             • dependent on fossil fuels
               • emission will increase
         • clearing vegetation
           • remove forests
             • need burning
               • release carbon dioxide
                 • fewer trees left
                   • lesser absorption of carbon dioxide

2. Cause of Changing Climate

   • urban development
     • clearing of trees
       • less vegetation
         • more carbon dioxide
           • leads: higher temperatures
             • resulting in: "heat island effect"
               • warmer wet surface
                 • favours formation of clouds and rain
     • concrete buildings
       • absorb + retain heat effectively
     • dense and tall buildings
       • block wind flow
         • prevent cooling
           • lower wind speed
             • higher the temperature
     • busy urban activities
       • e.g. transportation
         • large demand on power
           • meaning: fossil fuels
             • produces: man-made heat, greenhouse gas, dust
       • produce: dust, dirt
         • cause air pollution
           • reduces visibility

3. possible benefits

   • save more energy in cold areas
     • ∵ shoter and warmer winters
   • more energy resources found
     • ∵ melting of ice
   • grow more food
     • ∵ longer growing season
   • water shortage eased
     • ∵ rainfall increases
   • fewer death cases
     • ∵ less severe winters
   • creates shorter shipping routes

4. harmful effects

   • melting ice at the Poles
     • ∵ world getting warmer
       • ice shrinks + gets thin
         • ice melts
           • sea level rises
     • causes seawater to heat up and expand
       • rises in sea level
         • low-lying areas: more flooding
   • more climatic hazards
     • flooding
       • ∵ wet areas: high temperature
         • more evaporation + rain
           • increase ranfall + flooding
     • drought
       • dry areas
         • lower humidity
           • unfavourable weather conditions for cloud and rain
             • more droughts
               • less vegetation
                 • soil erosion + desertification: increase
     • heat waves and wildfires
       • persistent high temperature
         • cause heat waves
           • more droughts happen
             • wildfire: more serious and frequent
     • stronger typhoons and blizzards
       • warm atmosphere
         • more evaporation
           • release more energy
             • make storms powerful
   • spread of disease
     • warmer climare --> extend poleward
       • tropical disease: easily spread
   • extinction of species
     • ∵ frequent change of temperature + rainfall
       • plant's + animal's habitat change
   • disruption of crop yields + food supply