Water, Carbon & Climate

• How do water , carbon & climate sustain life?

  . Carbon is a fundamental building block

  . All organisms need water

  . Plants form base of food chain and use photosynthesis (requiring &) to make biomass

  . Water present in atmosphere as water vapour and carbon as $CO_2$ & $CH_4$: GGs = natural greenhouse affect = habitable earth
• Interactions between Water , Carbon & Climate :

  . carbon combines with water in atmosphere = chemical weathering (C removed from atmosphere )

  . water needed for photosynthesis to remove C from atmosphere

  . amount of CO2 affects global temp = affects evaporation = affects precipitation
• Human influences on Climate Change :

  . 40% more $CO_2$ in atmosphere than 1750

  . UN organisation : Intergovernmental Panel on Climate Change set up to share knowledge

  . states countries need to reduce emissions by human activities to prevent global warming
• Impacts of Climate Change:

  1. Precipitation patterns change = water shortages = conflict ⚠️
  2. Extreme weather events 🌪️ more frequent (LICs less prepared = worse impact)
  3. Agricultural productivity ⬇️ = food shortages 🥕
  4. Sea level rise = flooded coastal/low lying areas
  5. Species geographical range changes as climates do = new species damage ecosystems & extinction
  6. Plankton numbers decrease due to temp increase = disrupts marine food chains
• impacts of climate change can be mitigated by reducing carbon flows to atmosphere on different scales
• mitigation :


  reducing the severity of/ harmfulness
• Individual mitigation :

  . less cars or fuel efficient / electric 🚙

  . energy efficient homes ( insulation + double glazing )
• Regional / National mitigation :

  . GOVS reduce reliance on FF to power homes by increasing availability & decreasing cost 💲of renewable energy

  . aforestation to increase C uptake by biosphere

  . increase development sustainability (green space & transport)

  . invest in carbon capture & storage
• Global 🌎 Mitigation :

  . work together to reduce emissions

  eg : Kyoto Protocol 1997 & Paris Agreement 2015 - international treaties to control GG , ppt countries agree to keep in limits

  . International Carbon trading schemes : business/countries given limit on emissions

  produce less = sell credits