Energy demand is growing as a result of:

• increasing population

• changes in consumer demand

• increasing demand from different sectors: transportation, domestic use, industry, agriculture

• development and improving quality of life

• climate change

Energy security is important as access to affordable energy has become essential to the functioning of modern economies. Energy is unevenly distributed, leading to issues such as war, changing prices and inequality.

Fracking is a method to extract methane (gas) from shale (an impermeable sedimentary rock). Horizontal drilling is used to access the shale and hydraulic fracturing, chemicals, sand and water are used to in the production of shale gas. 

The shale gas is used to generate electricity or supply natural gas to homes and businesses.

Benefits of shale gas extraction:

• Increased energy security

• Jobs

• Widespread reserves

Challenges of shale gas extraction:

• Greenhouse gas emissions

• Aquifer/groundwater contamination

• Induced seismicity

• Visual & noise pollution

Hydrogen is sourced from natural gas, biomass and water.

It can be produced via four processes, which all aim to separate hydrogen atoms from where it is found naturally:

• Steam methane reforming - natural gas reacting with steam under high temperatures/pressures (in the presence of a catalyst) to produce hydrogen and carbon.

• Gasification - coal or biomass is reacted with steam at high temperatures, without combustion taking place, producing carbon monoxide and hydrogen gas.

• Pyrolysis - heating biomass or coal in the absence of oxygen, producing hydrogen and carbon monoxide.

• Electrolysis of water - splitting water molecules into hydrogen and oxygen using electricity and an electrolyser (fuel cell). If the electricity is renewable, this is known as green hydrogen.

Advantages of hydrogen power:

• Abundant and readily available

• Can lower GHG emissions (when produced by electrolysis)

• Fuel cells run silently and don't have moving parts

• Range is greater than electric

Disadvantages:

• Can use more energy to produce hydrogen than is recovered

• Low density, so requires a large storage area

• Fuel cells are expensive to produce

• Infrastructure needed (e.g. refuelling)

• Range is less than petrol/diesel cars

Water demand is growing as a result of:

• increasing population

• changes in consumer demand

• development and improving quality of life

• climate change

Whilst places with low rainfall can suffer water insecurity, it can also be caused by population growth in water-poor areas, international competition over water sources or climate change.

Desalination can create new freshwater resources. It is widely used in arid and semi-arid areas, particularly in coastal regions.

Desalination is:

• Energy intensive

• Produces waste products

• Expensive

Other management techniques focus on water conservation. 

In agriculture, this includes:

• Using improved irrigation practices e.g. drip irrigation 

• Using drought resistant crops created through conventional breeding and genetic engineering.

In industry, this includes: 

• changing processes e.g. reducing water pressure

• replacing equipment e.g. fixing leaks

• re-using greywater and blackwater 

Farms are changing the way that they manage land to increase food production. 

Intensive agriculture prioritises minimising inputs and maximising outputs by.

Regenerative agriculture aims to use processes which support biodiversity, climate, soil health and water.

Strategies of intensive farming include:

• Bigger fields & larger farms

• Crop rotation

• Drainage

• Hedgerow removal

• Cultivation of marginal land

• Conservation practices

• Diversification

Scientists have made progress in food production by:

• Selective breeding - breeding together plants or animals which have beneficial characteristics

• Cross breeding - breeding together different plant or animal species to achieve beneficial characteristics. An example of this was breeding high yield varieties (HYVs) during the green revolution.

• Genetic engineering (GM) - altering DNA in an organism to make changes to characteristics

• Using hydroponics - growing plants in a soil-less medium or in water.

Aquaculture is the farming of aquatic animals (e.g. salmon) and plants (e.g. kelp) for food. Strategies to increase production include:

• High density cages

• Pesticides

• Selective breeding

Marine fisheries catch fish directly from their ecosystem (e.g. herring, cod). Managing the stock in a fishery (e.g. by using quotas or licenses) can prevent overfishing.

The Marine Directorate (formerly Marine Scotland) is a key environmental agency which is responsible for monitoring, conserving and issuing licenses in Scotland's seas, coastal waters and freshwater fisheries.

Waste is generated when we produce and consume things. It can impact:

• air quality

• water quality

• landscapes (including marine environments)

• biodiversity

• climate change

Waste is becoming more of a problem because of:

• Population increase

• Globalisation

• Packaging

• Obsolescence - technical, planned and psychological

The waste hierarchy ranks waste management options according to what is best for the environment.

These are:

• Prevention - preventing waste in the first place by keeping products for longer, using less materials, preventing food waste, education

• Reuse - items need prepared for reuse. This can include checking, cleaning, repairing, refurbishing and using either the whole item or its parts.

• Recycling - this is when waste is turned into a new substance or product. It includes composting. Recycling can be:

  • Open loop: there is a loss of quality with each cycle

  • Closed loop: when a product can be recycled indefinitely

• Recovery - burning of waste to generate electricity/heat

• Disposal - in landfill or burning without energy recovery

To understand the environmental impact of a product, a life cycle analysis can be competed. This is a systematic, quantitative assessment which assesses all energy, materials and transport involved in making, using and disposing of a product.

Most economies currently operate on a linear economy model. This means that we take, make and dispose of products.

An alternative is the circular economy model. This involves designing products which can be made, used and returned.