climate change

• evidence of climate change

  .fossil records have found fluctuating temperatures and trapped oxygen molecules can tell temperature from that exact time

  . shrinking glaciers and melting ice highlight global warming

  .rising sea levels are caused by thermal expansion, glaciers melting causing islands to be in danger of flooding

  .seasonal changes show that bird migration is advancing as they are having to relocate to find appropriate temperatures
• natural causes of climate change

  orbital changes: eccentricity is every 100,000 years when Orit changes to oval so we get closer to the sun. axial tilt is every 41,000 years the tilt moves between 21.5º to 24,5º. precession is over 26,000 years when axis wobbles from one extreme to another

  solar activity: sunspots increase then decrease causing reduced surface temperatures

  volcanic activity: ash blocks out sun reducing temps ad sulfur dioxide reflects sun away from earth
• greenhouse effect keeps earth naturally warm as greenhouse gases e.f CO2trap heat in atmosphere allowing short term radiation into earth and trapping longer wavelength radiation
• human impacts on greenhouse effect

  CO2 which is released via the burning of fossil fuels contributes 60% of warming caused by greenhouse gases. deforestation causes less CO2 to be absorbed and farming causes more methane.
• managing climate change

  alternative energy -renewable resources don't burn fossil fuels

  carbon capture- technology that captures CO2 so it doesn't get released into atmosphere

  planting trees- they absorb CO2 via photosynthesis

  international agreements- e.g pars agreements where it aimed to keep global within 1.5ºC of industrial levels
• adaptations due to climate change

  agriculture- learn to cope with extreme weathers, store water and use efficient irrigation systems, plant trees to shade seedlings

  rising sea levels- construction of sea walls, mangrove forests restored, houses on stilts and construction of artificial island