Mitigating Impacts of Climate Change (AQA A Level Geography)

Changing Industrial Combustion

• Modifying industrial carbon transfers helps mitigate the impacts of climate change

• Some of the initiatives include :

  • Target setting to reduce greenhouse gas emissions globally

  • Switching to renewable sources of energy on a national scale

  • 'Capturing' carbon emissions and/or storing or burying them (sequestration) to reduce industrial emissions

  • Reduction in global deforestation 

  • Changes to land use

• Carbon capture and storage (CCS) uses technology to capture CO₂ emissions

• They can catch 90% of emissions, which could cut global carbon emissions by 19%

• CCS chain consists of 3 parts:

  • Capturing - separation of CO₂ from gasses produced

  • Transporting - pumping CO₂ through a pipeline or ship to storage locations

  • Storing CO₂ - in places such as deep mines, depleted oil and gas fields, deep oceans and saline aquifers

• CCS technology can be used for hydraulic fracturing (fracking) to extract oil and gas by pumping the CO₂ into the ground, with the increased pressure forcing oil and gas out and leaving the CO₂ behind

• CO₂ can be stored directly in sedimentary rocks by turning it into a high pressure liquid (supercritical CO₂) and injecting it into the rock

• Over and underlying impermeable rock act as a geochemical trapping mechanism, preventing CO₂ escaping to the surface

Changing Land Use

Changing land use

• Grasslands are able to sequester approximately 810 million tonnes of CO₂ globally

• Farming is one of the main causes of land use change

• Peatlands are thick organic soils that are low in oxygen and high in water

  • This inhibits microbial decomposition of plant litter allowing for thick organic layers to build

  • UK peatlands have taken approximately 7000 years to develop and are often 2-4meters deep

  • The organic matter found within peat is 50% carbon and therefore, peatlands are a major soil carbon sink

  • Restoration of peatlands will increase carbon storage and removal from the atmosphere

  • Not using peat in compost for household gardening will also reduce the depletion of peatlands and therefore, improve carbon soil stores

• Grassland carbon storage can be improved through:

  • Avoiding overgrazing by livestock

  • Adding manures and organic material rather than artificial fertilisers

  • Stock and crop rotation to allow grassland and soil to recover

  • Carbon farming - one type of crop is replaced by another that absorbs more CO₂ from the atmosphere - legumes and grasses

  • Irrigation and water management improves plant productivity and prevents soil leaching

  • Reduced ploughing (zero tillage) of fields avoids rapid decline of soil quality and carbon release

  • Polyculture, where growing annual crops in between trees helps protect soils from erosion and boost stores of carbon

Changing deforestation

• Protect existing forests which will preserve current soil carbon stocks

• Reforesting degraded lands along with increasing tree density will improve biomass density and therefore carbon density, above and below ground

• Trees in croplands (agroforestry) and orchards can store carbon above and below ground

• CO₂ emissions can be reduced if trees are grown as a renewable source - certification by the Forestry Stewardship Council (FSC) shows people that timber has been grown sustainably

• Carbon payments can be made by countries, organisations or individuals to offset carbon emissions

• Debt for nature swap:

  •  In 2010 the USA converted US$13.5 million of debt from Brazil into a fund to support the protection of the rainforest

• The International Tropical Timber Agreement (ITTA) promotes sustainable forest management and restricts the trade in rainforest hardwood timber (hardwood timber is a slow-developing wood and therefore, holds more carbon within the wood)

• Selective Management System in Malaysia allows for small-scale selective logging and replanting of trees

Changing photosynthesis

• Photosynthesis where primary producers convert carbon dioxide from the atmosphere and water from the soil, into oxygen and glucose using light energy and thereby, removing CO₂ from the atmosphere

• There is evidence that plant growth increases with higher atmospheric CO₂ levels, but only to a point that then levels off 

• Anything that increases primary producers such as phytoplankton, trees grasses etc. will increase photosynthesis which increases the removal of CO₂ from the atmosphere

• Agroforestry is particularly effective in absorbing CO₂ as compared to natural forests

• Afforestation

  • The Forestry Commission, National Trust and the Woodland Trust, landowners and local authorities are involved in increasing tree planting in the UK which is helping carbon sequestration

  • The Big Tree Plant campaign encourages communities to plant 1 million new trees, mostly in urban areas 

• Restoring peatlands where carbon has been removed from the atmosphere by peatland plants through photosynthesis

• Scientists are developing a suite of genetically engineered crops that will more efficiently remove and store carbon dioxide from the atmosphere

• Water is often the main limiting factor for photosynthesis as it acts as a solvent for all the chemical reactions in cells

• Plants can photosynthesise over a wide range of temperatures from 0°C to around 50°C

• The optimum temperature for most plants is 15°C to around 40°C

• Temperature affects the rate of photosynthesis in crop plants and affects where certain crops can be grown

• Rising temperatures will negatively affect crop production 

• Any long-term solution needs to rebalance the carbon and water cycles, particularly in reducing the concentration of greenhouse gases in the atmosphere

• Many mitigation strategies are complex, with perhaps the exception of afforestation, and successful outcomes require a societal shift in attitude and actions long-term

Role of Political Initiatives

1997 Kyoto Protocol

• This was to be a legally binding reduction of CO₂ emissions by many high-income countries (although the USA and Australia refused to sign)

• Its aim was to cut global greenhouse gas emissions by 5% from 1990 levels by 2012

• Many newly emerging countries (China, India etc.) were exempt

• Most of the EU and Japan were expected to cut emissions by 7%

• The Kyoto Protocol came into effect in 2005 but discussions continued around different levels of compliance among countries 

2015 Paris Climate Convention

• 195 countries adopted the agreement to reduce global CO₂ emissions to below 60% of 2010 levels by 2050

• The agreement also set out a plan to limit the average global temperature increase to 1.5°C above pre-industrial levels

• Countries were allowed to set their own targets with no detailed timetable to follow

• HICs further agreed to share technology and send funds to NEEs and LICs to help achieve their targets

• LICs and NEEs argued that their current levels of development meant using cheaper fossil fuels to increase their people's living standard to match HICs and why should they be made to reduce their emissions

• They argued that HICs had gained their current standards through industrialisation and the use of fossil fuels over the past 200 years, which made them responsible for the increase in current greenhouse gases

Cap and trade

• Carbon offsets are credits for schemes that promote carbon sequestration (i.e. afforestation) or reduce emissions (i.e. use of renewable energy)

• The Kyoto Protocol initiated the idea of trading unused carbon emissions (carbon credits) 

• In theory, if a country cut its emissions below its 'cap', then another country could buy these 'credits' to offset their emissions above their agreed levels to meet their emission target or cap

• In reality, very few countries achieved their cap and carbon credit trading wasn't successful 

  • New Zealand joined the Protocol in the belief they would make money selling their spare credits

  • In reality, New Zealand exceeded their emissions cap and had to pay a fine 

• The idea that polluters have to pay while clean countries are rewarded

• The EU introduced a similar carbon credit system in 2005, if individual and energy-intensive businesses, such as refining and cement industries, achieved emissions below their set level, which they could then sell

• A Clean Development Mechanism is where HICs invest in emission-reducing projects in LICs or NEEs 

• Investments in projects such as forest conservation, peat and wetland restoration offset expensive emission-reduction projects in HICs