topic 2

• Adaptation


  Initiatives and measures to reduce the vulnerability of human and natural systems to climate change
• Albedo


  The amount of incoming solar energy reflected back into the atmosphere by the earth's surface
• Anthropogenic


  Human related processes and/or impacts
• Enhanced greenhouse effect

  Increasing amount of greenhouse gases in the atmosphere, as a result of human activities, and their impact on atmospheric systems, including global warming

  
• Global warming


  The increase in temperatures around the world that have been noticed since the 1960s, and in particular since the 1980s

  
• Greenhouse effect

  The process by which certain gases allow short-wave radiation from the sun to pass through the atmosphere and heat up the Earth, but trap and increasing proportion of long-wave radiation from the Earth. This radiation leads to a warming of the atmosphere.

  
• Mitigation

  Attempts to reduce the causes of climate change
• Resilience

  The ability of population or a human or natural system to absorb change without having to make a fundamental change.
• Vulnerability

  Degree to which a human or natural system is susceptible to, and unable to cope with, the adverse impacts of climate change.
• Atmosphere is a mixture of solids, liquids, and gases held near to the Earth by gravitational force, up to a height of approx. 80km
• Composition of the atmosphere

  • Nitrogen (78%)
  • Oxygen (21%)
  • Argon (0.9%)
  • Other gases such as CO2, helium, and ozone
  • Water vapour and solids (aerosols) such as dust, ash and soot
• The atmospheric energy balance is an open energy system receiving energy from both the Sun & Earth
• The energy that drives weather & climate comes from the sun
• Earth absorbs most of its energy in the tropical regions vs lose the most at the poles
• Redistribution of energy from lower latitudes to higher latitudes is caused by wind circulation & ocean currents
• Under natural conditions, the balance in the atmospheric energy budget is achieved through radiation, convection, and conduction
• Only 46% of the insolation at the top of the atmosphere actually gets through to the Earth's surface, 31% is reflected back into space, and 19% is absorbed by atmospheric gases
• Incoming (short-wave) solar radiation

  • It is the main energy input, not absorbed by the earth's atmosphere, instead they heat the Earth, in turn, emits long-wave radiation
  • Affected by latitude, season, and cloud cover
• Long-wave radiation

  Radiation of energy from the earth (a cold body) into the atmosphere and, for some of it, eventually into space
• Greenhouse effect

  The process by which certain gases allow short-wave radiation from the Sun to pass through the atmosphere but trap an increasing proportion of outgoing long-wave radiation from the Earth, leading to a warming of the atmosphere

  
• Greenhouse gases

  • Water vapour
  • Carbon dioxide
  • Methane
  • Chlorofluorocarbons (CFCs)
• Water vapour accounts for 95% of the greenhouse gases by volume and 50% of the greenhouse effect
• Carbon dioxide levels have risen from 315 ppm in 1950 to 400 ppm in 2012, expected to reach 600ppm in 2050, due to human activities: burning fossil fuels, deforestation. CO2 accounts for 20% of the greenhouse effect

  
• Methane is the 2nd largest contributor to the greenhouse effect, with increased presence by 1% per annum, emitted by cattle, paddy fields, wetland, bogs trapped in permafrost that is melting
• Chlorofluorocarbons (CFCs) are synthetic chemicals that destroy ozone, increasing at a rate of 6% per annum, and are 10,000 times more efficient at trapping heat than CO2
• Global dimming

  Air pollution having a cooling effect on earth's temperature

  
• Positive feedback

  A change in the Earth's energy balance leads to an amplification of that change
• Negative feedback

  Change in the Earth's balance leading to a reduction or stabilisation of that change
• Enhanced greenhouse effect

  The impact of increasing levels of greenhouse gases in the atmosphere as a result of human activities, often referred to as global warming

  
• Global warming refers to changes in global patterns of rainfall and temperature, sea level, habitats and the incidence of drought, flood and storms, resulting from changes in the Earth's atmosphere, believed to be caused by the enhanced greenhouse effect

  
• Global warming is linked to industrialisation, trade and globalisation