Earth’s life support systems

• Global management strategies to reduce carbon footprints

  • encourage car free zones, family member limits, new national and local laws and legislations
  • Implement Kyoto protocol and Cop28 aims more severely to improve sustainability
  • Carbon capture and storage techniques: condense carbon to a liquid and store underground.
  • > pre combustion capture - generates renewable energy
  • > post combustion capture - absorber columns absorb co2 through heated steam and is collected for geosequestration underground
  • > these can be incorporated into infrastructures to reduce companies carbon footprints
• > positive feedback loops: build on actions that have happened within the system, exacerbating the effects of a disequilibrium

  > negative feedback loops: counteracts any changes made to the system, maintaining a stable equilibrium
• Water cycle: water extraction

  > Water confined between impermeable rock layers with and sedimentary rocks above is placed under artesian pressure.

  
• Changes occurring within the carbon cycle : Use of fossil fuels

  > between 2019 - 2023 : fossil fuels accounted for 80% of global energy consumption

  > 10 billion tonnes of co2 was released into the atmosphere

  > anthropogenic emissions equated to 2000 GT

  they impact the size of the stores: atmosphere, biosphere and hydrosphere
• Changes occurring within the carbon cycle : Sequestration of waste carbon (solution)

  Carbon, capture and storage techniques (css)

  1. co2 is separated from power station emissions
  2. co2 is compressed and transported by pipe line to storage areas
  3. it is injected into porous rock underground and stored permanently reducing emissions by 80-90%

  effectiveness of CSS is limited by:

  • uses large amounts of energy
  • needs to be near porous and impermeable rock strata
  • big capital costs: Drax and Peterhead power station, North Yorkshire spending £400k on a css prototype.
• Methods used to monitor short term changes in the water & carbon cycle (pt.1)

  >Artic sea ice: NASA's earth absorbing system (EOS)

  • satellites monitor sea growth and retreat
  • carbon - shows photosynthetic activity
  • water - shows levels of sea level rise and sources of store transfers

  > Ice caps and glaciers: satellite tech estimates mass, balance and height of ice sheets and glaciers with laser technology.

  • shows volume and extent of ice changes
• Methods used to monitor short term changes in the water & carbon cycle (pt.2) 


  > Sea surface temperatures (SSTs)

  • Radiometers measure wave band of radiation emitted from ocean surface
  • records changes in global SSTs and areas of upwelling and downwelling (carbon)
  • temperature changes could give indication to rates of evaporation (water)

  > Water vapour : NOAA polar orbiters

  • measures cloud liquid water and total precipitable water
  • records long term trends in cloud cover and water vapour in atmosphere
• Methods used to monitor short term changes in the water & carbon cycle (pt.3)

  > Deforestation: ESA albedo images from various satellites measure the reflectivity of the earth's surface and land use changes

  
  

  > Primary production in oceans: NASAs AQUA programme

  • measures net primary production (NPP) in oceans and on land

  > Atmospheric co2: NASAs Orbiting Carbon Observatory 2

  • measures global atmospheric co2 and effectiveness of absorption of co2 by plants
• How do human activities cause changes in the water cycle stores?

  > Rapid population growth increases demand for water for irrigation, agriculture and public supply resulting in shortages of water in rivers and aquifers

  > quality of fresh water declines due to pollution and industrial uses

  • over pumping in Dhaka has caused groundwater levels to drop more than 200 feet over the last 50 years

  > urbanisation and deforestation has reduced infiltration rates, reducing through flow and reducing the water table

  Also lead to increased evaporation rates leading to more water in the atmosphere
• How do human activities cause changes in the carbon cycle stores?

  > Exploitation of coal, gas and oil removes billions of carbon from geological store to atmosphere

  > deforestation transfers 1 billion tones of carbon to the atmosphere annually

  > 2.5 million tonnes of carbon is absorbed by oceans and the biosphere each, however this storage has reduced due to decline of trees, soil erosion and increase in ocean acidity

  > carbon stores in wetlands are drained for cultivation and developments, releasing carbon and later dry out, becoming oxidised
• Management strategies of the water cycle - Forestry 


  > UNs world bank and WWF work with government to protect forests

  UNs REED conservation project fund over 50 partner countries in Africa, Asia and South America, including Brazil:

  • ARPA project successfully protects 128 million acres of Amazon out of 150 million goal
  • deforested land decreased from 16 million in 1990s to 10 million in 2020
  • this project stabilises the regional water cycle, supports indigenous communities and conserves wildlife and biodiversity
• Management strategies of the water cycle - Water allocation

  Government allocate water to priority areas that need the resources

  • 70% is withdrawn for agriculture and 90% is for public consumption
  • Results in water scarcity-US Colorado Basin
  • water wastage occurs through evaporation and seepages from over-irrigating crops
  • to reduce this:

  >mulching, drip irrigation and zero soil disturbance to reduce evaporation

  >terracing and contour ploughing to reduce runoff

  >better water harvesting with storage ponds and reservoirs

  >recycling of waste water from agriculture and urban populations
• Management strategies of the carbon cycle - Agricultural practices

  Over cultivation and overgrazing leads to soil erosion and carbon release

  management:

  • growing crops without ploughing the soil conserves soils organic contents, reducing oxidation and erosion by wind and water
  • polyculture : growing annual crops interspersed with trees which provides ground cover, protecting soils from intense sunlight and erosion
  • avoiding use of heavy farm machinery on wet soils which leads to compaction erosion
  • using anaerobic containments with manure prevents methane being released by surface runoff
• Management strategies of the carbon cycle - international agreements

  > Kyoto protocol (1997): rich countries agreed to legally binding reductions in carbon emissions

  > Cop28: transition away from fossil fuel uses and cut emissions by 43% by 2030

  > Paris agreement: to reduce co2 emissions below 60% of 2010 levels by 2050

  • China and India exempt as they rely of fossil fuels to compete with the modern world and global market
  • rich countries transfer funds and technology to assist poor countries to reach targets
• Management strategies of the carbon cycle - Cap and Trade

  > Businesses offered annual quota for their co2 emissions

  • if they emit less than their quota they receive credits to trade on international markets
  • if they exceed their quotas they face financial penalties

  > Afforestation, renewable energy and wetland restoration projects to increase carbon stores are also rewarded
• more infiltration / runoff results in saturated overland flow
• higher altitudes means colder temperatures and slower rates of decomposition