6.7c shifting climates

• current evidence of shifting climates

  • hot desert expansion
  • poleward movement of stormy wet weather in the mid latitudes
  • tropical rainforest becoming savannah grasslands
• Amazonia role

  • key element in offsetting anthropogenic carbon emissions
  • tipping point - change becomes self sustaining when pushed beyond a certain threshold
• Drought in Amazonia

  • more frequent and severe
  • due to global warming, changing position of ITCZ and increasingly intense El Nino events
  • deforestation exacerbating
  • die-back
• Amazonia is:

  • declining as a carbon store
  • less sequestration from atmosphere - exacerbating enhanced greenhouse effect
  • diminished role in hydrological cycle
• Afforestation

  • afforestation is a solution but a mature tree is a much larger carbon store than a newly plants tree
  • die-back affects younger trees first - less resilience
• Peatlands

  • temperatures warm - drying out peatlands
  • drier peat, catches fire
  • releases CO2 and methane into atmosphere
• management of peatland

  by 2018, 95% of peatlands have some degree of protection - largely due to UK Peatland Strategy