Geography

Geography

1. Climate and Change

   • Weather and Climate
     • Climate- Average atmospheric conditions over many years
       • Polar, Tropical,Temperature
     • Weather- Average atmospheric conditions on a day-to-day basis
       • Precipitation, Temperate, Anticyclones
     • Line graph represents temperature (continuous data)
     • Bars represent rainfall (discontinuous data) (mm)
     • Fluctuate- Goes up and down
     • Describing a graph- Trends, Examples, Anomalies (TEA)
   • Global Warming
     • Greenhouse effect
       • Ultraviolet sunlight reaches earth's atmosphere
       • Most UV light reaches earth's surface
       • Some UV light reflected back to space
       • UV light heats ground
       • Ground gives off Infrared heat
       • Infrared absorbed by greenhouse gases
         • Humans adding nitrous oxide,CH4,etc.increasing these increases amount of trapped heat
           • How humans are increasing the TGE
       • Greenhouse gases transmit heat back to earth
     • What is climate change and is it natural?
       • Greenhouse gases
         • Methane (Ch4)
         • CarbonDioxide (CO2)
         • Nitrogen oxide (NO2)
         • Water vapour (clouds=water droplets+clouds interfere with sunlight as they block the sunlight and give off heat
       • Orbital change
         • Shifts from circular to elliptical over 100,000 years (Geological change), meaning sometimes earth's closer to sun, sometimes further away
         • Earth's axis at 23 1/2 degrees, then 22 1/2 then 21 over 41,000 years
         • circular to elliptical change lines up with temp. on a graph
         • Earth wobbles towards /away from sun over 23,000 years. Elliptical change creates Ice age as further from sun so snow doesn't melt properly
       • Sun spots
         • Sun has spots so more spots=more heat=warmer on earth but less spots=less heat=earth isn't as warm
       • Volcanic activity
         • big eruption, particles sulphur dioxide ash, hydrochloric acid released into traposphere (first layer of atmosphere+less stable) and rise to stratosphere (second layer, more stable)
         • These particles block the sunlight once they rise to the stratosphere
         • SO2. Ash, HCl are aerosols meaning they reflect sunlight,so more heat is reflected back to earth
   • Different time periods
     • Long term- Geological change (100,000 years ago)
     • Medium term- 100s and 1000s of years ago (Historical change)
     • Shorts term- 100s of years ago (Recent change)
   • How has human activity affected recent climate change?
     • Increases amount of CO2 made by humans
       • Deforestation
         • Trees are a CO2 sink meaning it absorbs CO2 but less trees=less CO2 absorbed
       • Burning fossil fuels
         • Releases CO2 into atmosphere
       • Driving fuels
         • Releases CO2 into atmosphere from petrol
     • 77% of greenhouse gases produced by humans is CO2
       • CO2 increases temperature
       • Methane(CH4) is 14% of greenhouse gases,but is 21% more powerful than CO2
         • Methane produced by cows(mostly burps).Humans breed them so more cows=more methane
           • Bacteria in cows' stomachs(they have 4)produce methane and not CO2 as they have no O2 to breathe in
         • Odourless gas
         • Also comes from rice fields as bacteria in soil has no O2 to breathe in as H2O used for water acts as a barrier so since they can't breathe in O2 and release CO2 they produce methane
       • Nitrous oxide is 8% of greenhouse gases produced by humans,but it's x250 more powerful than CO2
         • Comes from chemical fertilizers and burning fossil fuels
           • Chemical fertilizers contain nitrogen+since needs to be in liquid form,it's combined with O2,making it nitrous oxide
   • Climate change=the effect
     • The Greenhouse Effect=the process

2. Ecosystems

   • How is climate linked to ecosystems?
     • Ecosystem-Community of trees,plants,animals,insects living in a particular environment
     • Biome-Ecosystem covering a large area of the Earth's surface.It can be land or water
       • E.g.Temperate rainforests,tropical rainforests,tundra &ice,desert,grassands