Human Impact

• Enhanced Greenhouse Effect

  • Increasing CO2 in atmosphere - 270ppm —> 500ppm
  • Build up of greenhouse gases due to human activity
• Atmospheric impacts

  • Rise in Sea levels - 200mil could be displaced by 2050
  • increased storm activity
  • 4bn in water shortage if temp up by 2*
  • 200mil exposed to hunger if temp up by 2*
• Paris Agreement

  • 2015
  • 174 countries signed
  • limit warming to 2*
  • net zero emissions by 2050
  • No country-specific goals
• Urban Climates - Urban heat island

  • Extra heat sources
  • Albedo much lower
  • Heat released slowly at night
  • Trapped radiation
  • dust = increased concentrations of hygroscopic particles
  • relative lack of moisture = reduced relative humidity
  • Greater cloud cover in summer & radiation fog in winter
  • 0.6* warmer average
  • Disrupted air flow - large buildings can produce eddying and canyon effect