climate change

• what are 3 natural causes of climate change?

  • volcanic activity
  • changes in the Earth's orbit
  • variations in heat output from the Sun
• what are some global effects of climate change?

  • glaciers and ice caps melting
  • artic sea ice is less extensive than the past
  • low lying islands under threat from sea - levels rising
  • sea levels may rise by 1m in 2100
• how can proof be found for climate change through ice cores?


  • layers of snow and sediment trap and preserve evidence of the global temp at the time
  • scientists can study the oxygen in the ocean sediment or water molecules in ice to calculate temperature
  • accurately dated
• how can volcanic activity cause climate change?


  • volcanic ash can block out the sun - temporarily reducing temp of the earth
  • fine droplets from the conversion of sulphur dioxide to sulphuric acid act like mirrors reflecting radiation from the sun - long term
• how can solar output affect climate change?


  • Sun has sunspots - dark patches that appear on the surface of the sun
  • sunspot output at a maximum - sun gives off more heat + large explosions occur on the surface of the sun resulting in solar flares
  • Sunspot output at a minimum - solar output is reduced - lead to lower temperatures on Earth
• what are the three cycles of the Earth?

  • Eccentricity
  • Precession
  • Axial tilt
• what is eccentricity?


  • The path of the Earth as it orbit the Sun - orbit is not fixed
  • Changes from mildly elliptical to circular
  • complete cycle occurs every 100,000 years
• what is precession


  • natural 'wobble'
  • complete cycle 26,000 years
  • Accounts for certain regions of the world e.g Northern Norway experiencing very long days and very long nights at certain times of year
• what is axial tilt?


  Earth spins on its axis causing night and day

  Over a period of 41,000 years it moves back and forth between 21.5 degrees and 24.5 degrees
• How do the earth cycles affect climate change?


  • scientists believe they affect the timings and seasons of the Earth's climate
• what ways have humans increased the amount of nitrous oxides in the atmosphere?


  • sewage treatment
  • agricultural fertilisers
  • car exhausts
  • power stations producing electricity
• how have humans increased the amount of methane in the atmosphere?


  • rice farming
  • burning biomass for energy
  • farm livestock
  • decaying organic matter in landfill sites and compost tips
• how have humans affected the amount of CO2 in the atmosphere


  • car exhausts
  • deforestation and the burning of wood
  • burning fossil fuels in industry and power stations to produce electricity
• what is the greenhouse effect?


  • The atmosphere allows most of the heat from the Sun to pass through it to warm up the Earth's surface
  • The Earth give off heat in the form of long wave radiation, greenhouse gases are able to absorb it
  • The greenhouse effect keeps the earth warm
• what is carbon capture?

  • Uses technology to capture C02 produced from the use of fossil fuels in electricity generation and industrial processes
  • carbon gas is compressed and transported by a pipeline to an injection well
  • injected into the ground to be stored in suitable geological reservoirs
• what was the Kyoto Protocol 2005

  • over 170 countries agreed to reduce carbon emissions by an average of 5.2 per cent below their 1990 levels by 2012
  • USA and Australia refused to sign the treaty
• What happened in Copenhagen 2009?


  • World leaders met
  • Pledged to reduce emissions with financial support for developing nations to help them cope with the impacts of climate change
  • no legally binding agreement
• what was the Paris agreement 2015?


  • 195 countries legally binding global climate deal
  • 2017, USA withdrew
  • To keep global temperature increase below 2 degrees and limited to 1.5 degrees above pre-industrial levels
  • to review progress every 5 years
  • Achieve a balance between sources and sinks of greenhouse gases in the second half of the century
  • $100billion a year to support climate change by 2020
• how does planting trees reduce climate change?

  • trees are carbon sinks - remove CO2 from the atmosphere by photosynthesis
  • release moisture into the atmosphere
  • Has a cooling effect by producing a cloud, reducing solar radiation
• what are alternate sources of energy to carbon?


  • hydro - electricity
  • nuclear power
  • solar, wind and tides
• how can farmers react to climate change?


  • new irrigation systems
  • drought - resistant strains of crops
  • new cropping patterns introduced
  • educating farmers in water harvesting techniques
  • shade trees planted to protect seedlings from sunshine
• how are they managing sea levels in the Maldives?


  • artificial islands up to 3m high - people most at risk can be relocated
  • houses built on stilts
  • sea walls 3m high around the capital Male with sandbags used elsewhere
  • Restoration of coastal mangrove forests
• how are they managing water supply in the Himalayas?


  • Artificial glacier project
  • Water is collected in winter through diversion canals and embankments and freezes
  • When it melts in spring it will provide water for local villages
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