Issues of Energy Sustainability (AQA A Level Geography)

Enhanced greenhouse effect

• The world’s increasing need for energy security has led to an increase in the number of greenhouse gases in the atmosphere

• It is estimated that energy accounts for more than two-thirds of total greenhouse gas emissions globally

  • Carbon dioxide (CO2) levels in the atmosphere have increased by more than 100 parts per million (ppm) to 420 ppm in 2020

• Sources of greenhouse gases from energy production and consumption include:

  • CO2

    • Burning of fossil fuels  for power stations and vehicles

    • Burning of wood for heating and cooking in LICs

  • Methane

    • Emitted during the production and transport of coal, natural gas, and oil

    • Of the 135 million tonnes (Mt) of annual global energy-related emissions

      • 42 Mt are from coal mines

      • 41 Mt from oil

      • 39 Mt are from extracting, processing and transporting natural gas

  • Nitrous Oxide

    • Emitted during combustion of fossil fuels

• Increased amounts of greenhouse gases have led to the enhanced greenhouse effect:

  • Less long-wave radiation (heat) can escape the atmosphere

  • Average global temperatures have increased 1°C above pre-industrial times

• The enhanced greenhouse effect is leading to climate change with significant impacts on people and places

Acid Rain

Acid rain

• Sources of acid rain arise from the search for energy security

  • Burning of fossil fuels to generate electricity

  • Vehicles and heavy equipment.

  • Manufacturing, oil refineries and other industries

• Acid rain results when sulphur dioxide and nitrogen oxides are emitted into the atmosphere 

• They react with atmospheric water, oxygen and other chemicals to form sulfuric and nitric acids

• These then mix with water and other materials and are transported by wind and air currents

• Deposits can be also be dry, as gas and minute particles

• They can fall as acidic deposits far from the source

  • An example of transboundary pollution

• The impacts of acid deposits can be damaging to ecosystems and soils

  • Reduces the pH of bodies of water

    • Kills fish and affects spawning, e.g. of rainbow trout

  • Soil acidification reduces the availability of mineral ions

    • Plant nutrients leached out of the soil by percolation of acidic water

    • Toxic metals such as aluminium ions released

      •  Poisons plant roots

      • Kills microorganisms so soil is no longer broken down

    • Phosphates become fixed so dissolved aluminium increases

      • Phosphate becomes less accessible to plants

• Impacts can be all-year round, or ‘chronic’

• Or they can be ‘episodic’

  • After periods of heavy rain or snowmelt, large amounts of acid can be flushed out of soils into waterways

  • Known as an acid shock

• Sulphur emissions have fallen across Europe and North America in the last 20 years

• Only 10% of lakes in northeast USA are now affected by long-term chronic acidification 

• But episodic acidification is still an issue

  • 31% of northeast US lakes still affected by acid shock

• Emissions in China and other EMEs remain high so transboundary pollution still an issue in some parts of the world

Energy Conservation

Energy conservation

• Combined heat and power (CHP) is one strategy to conserve energy in industrial settings

  • Heat generated during electricity generation is transferred to other settings, e.g. to heat homes

  • Overall energy consumption is reduced 

  • Heating and electricity supplies remain cheap and stable

  • Denmark uses CHP networks to provide 60% of it’s space and water heating

• Other measures to conserve energy in homes and small businesses include:

  • Improving thermal efficiency of walls, windows and roof-spaces with insulation

  • Installing double-glazing to windows

  • Replacing tungsten light bulbs with LED bulbs

  • Sensors to turn lights off when not in use

  • Information to consumers about the energy efficiency of the appliances they buy

• New buildings in the UK have to be developed with strict codes to ensure energy efficiency

• Requirements include:

  • Thermal insulation

  • Air permeability (airtightness)

  • Energy-efficient heating systems

  • Lighting efficiency

  • Controls for heating, ventilation, and hot water systems

• The regulations set a limit on the carbon emissions from buildings

• Energy performance certificates to provide evidence of compliance