Energy Impacts, Sustainability and Case Studies

Question

Step-by-step solution

1. Step 1

   Pick a clear, specific impact (1 mark). Burning coal, oil and gas releases pollutants. A safe answer is air pollution (release of sulfur dioxide and particulates).

2. Step 2

   Develop the harm (1 mark). Say what it does: air pollution causes respiratory illness (asthma, lung disease) in cities, or forms acid rain that damages forests and lakes.

Question

Step-by-step solution

1. Step 1

   Way 1 — efficiency device (1 mark, +1 development). Replace old bulbs with LED lighting, which uses far less electricity for the same brightness, cutting the household's electricity demand.

2. Step 2

   Way 2 — reduce heat loss (1 mark). Install loft and wall insulation so less energy is needed to heat the home, or simply turn off appliances at the wall instead of leaving them on standby.

Question

Step-by-step solution

1. Step 1

   Climate change (2 marks). Burning fossil fuels releases CO₂, which traps heat in the atmosphere; global temperature is now ~1.2 °C above pre-industrial, raising sea levels and intensifying storms.

2. Step 2

   Air pollution (2 marks). SO₂, NO₂ and PM2.5 from burning fuel form smog, causing asthma and lung disease — a major problem in cities such as Delhi and Beijing.

3. Step 3

   Acid rain (2 marks). SO₂ dissolves in rain to form acid precipitation that damages forests, acidifies lakes and corrodes buildings. Reduced in many OECD states by clean-air laws, but still widespread in China and India.

4. Step 4

   Habitat loss / pollution (2 marks). Mining and drilling strip landscapes; oil spills (Deepwater Horizon 2010, Niger Delta) poison marine and coastal ecosystems; tar sands and fracking degrade large areas of land.

Question

Step-by-step solution

1. Step 1

   Energy conservation and efficiency (2 marks). Insulation, LED lighting, efficient appliances, public transport and electric vehicles cut demand, so less energy needs to be generated in the first place.

2. Step 2

   Switching to renewables (2 marks). Build solar farms, wind farms, hydro and geothermal to replace coal and gas; this lowers CO₂ emissions and reduces dependence on finite fossil fuels.

3. Step 3

   Storage, grids and a balanced mix (2 marks). Batteries store renewable output for when the sun does not shine; smart grids and international interconnectors balance supply and demand, while a mix of sources (including nuclear baseload) keeps supply reliable.

Question

Step-by-step solution

1. Step 1

   Name the example (AO1). The Three Gorges Dam on the Yangtze River, China — the world's largest hydroelectric station, completed in 2012, with a capacity of about 22,500 MW.

2. Step 2

   Benefits (AO2). It generates renewable electricity meeting roughly 3% of China's demand (avoiding coal burning); it provides flood control on the lower Yangtze, protecting around 15 million people and 1.5 million hectares of farmland; and it improves navigation so large ships can reach inland Chongqing.

3. Step 3

   Costs (AO2/AO3). About 1.3 million people were displaced and historic and cultural sites were flooded; sediment is trapped behind the dam, the Yangtze finless porpoise is now critically endangered, and the weight of reservoir water has been linked to increased landslide and seismic risk.

4. Step 4

   Judgement (AO3). On balance the scheme delivers large-scale low-carbon energy and real flood protection, but at heavy social and ecological cost. Whether it is 'worth it' depends on weighting — for national energy security and emissions it succeeds, but for the displaced communities and damaged ecosystem the costs are severe and irreversible.

Question

Step-by-step solution

1. Step 1

   Argue for renewables (AO2). Renewables (solar, wind, hydro, geothermal) are effectively unlimited and emit almost no CO₂ in use, so they tackle both fossil-fuel depletion and climate change. Costa Rica ran on ~98–99% renewable electricity in recent years using hydro, geothermal and wind, showing it is achievable.

2. Step 2

   Limits of renewables (AO3). They are intermittent (no wind, no sun) so need expensive storage and grids; they have land and habitat footprints (HEP dams flood land, wind farms affect birds); and manufacturing solar panels uses energy and rare materials. Renewables alone cannot yet guarantee reliable baseload everywhere.

3. Step 3

   Other strategies (AO2). Energy conservation and efficiency (insulation, LEDs, efficient transport) cut demand cheaply; a balanced mix that keeps nuclear as low-carbon baseload and uses smart grids and storage often manages supply more reliably than renewables alone.

4. Step 4

   Judgement (AO3). Switching to renewables is necessary and the most important long-term strategy, but not sufficient on its own — it works best combined with conservation, storage and a managed energy mix. So I agree to a large extent, with the qualification that efficiency and a diverse mix are essential partners.