Energy Use and the Environment

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1Summary 重點摘要

Burning fossil fuels for power causes air pollution (particulates, sulphur dioxide) and carbon emissions. Switching to renewables and improving efficiency are the main fixes. Energy choices balance cost, reliability and environmental impact.

2Vocabulary cards Vocabulary

3Step by step Steps

1. Energy use and the pollution chainFrom extraction through combustion to emission, fossil fuels string together a chain of pollution. Coal-fired power emits sulphur oxides and nitrogen oxides, which dissolve in rain to form acid rain that damages forests, lakes and buildings; it also emits PM2.5, fine particulates small enough to reach deep into the lungs and harm health; and burning releases carbon dioxide, the main greenhouse gas behind global warming — extending the damage from the local to the global.
2. Comparing optionsEach energy option has trade-offs. Coal is cheapest and supplies are stable, but it is the dirtiest. Natural gas burns cleaner with less carbon dioxide, yet it is still a fossil fuel, and its extraction and transport carry environmental costs too. Nuclear power is almost carbon-free, but its waste must be isolated safely for a very long time and accident risk worries people. Wind and solar run at near zero emission but depend on the weather and are intermittent, needing grid balancing and storage to back them up.
3. Fix 1: cut emissionsThe first response is to cut emissions at the source of pollution and carbon: raise the share of renewables in the power mix, replace coal with cleaner fuels, retire old, inefficient generating units, and fit power stations with emission controls. Cutting emissions treats the root cause, improving air quality and easing warming at the same time — but it demands huge investment and an infrastructure transformation, and the results usually take years to show.
4. Fix 2: use lessThe second response is to use less electricity. One side is efficiency: switch to LED lighting and choose appliances with Grade-1 energy labels. The other is habit: switch appliances off standby and set the air-conditioner one degree higher. Energy experts often stress that the cleanest energy is the energy never used — every unit saved is genuine abatement, anyone can start today, and the cost is close to zero.
5. Hong Kong's power mixHong Kong has almost no indigenous energy resources. Power is supplied by two utilities, CLP and HK Electric, generated mainly from natural gas and coal, with about a quarter of the electricity imported from the Daya Bay nuclear plant. Recent policy direction is to replace coal with cleaner natural gas step by step, while studying offshore wind and waste-to-energy — seeking a balance between reliable supply and environmental protection, while cutting reliance on fossil fuels.
6. Limits on renewables in Hong KongDeveloping renewables in Hong Kong faces hard physical limits: land is scarce and high-rises are dense, so large wind or solar farms are impractical. The realistic options are offshore wind, plus solar panels on spare spaces such as reservoirs and landfills, which keeps local renewables a small share for now. Precisely for this reason, expanding regional cooperation and importing low-carbon electricity has become a key route for Hong Kong to cut carbon.

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5Worked example Example

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7Quick check Quick check

8Recap Recap

• Fossil fuels: pollution + carbon
• Choices balance cost, reliability, environment
• Two fixes: renewables + efficiency
• Coal brings both air pollution (SO₂, particles) and carbon (CO₂)
• Efficiency is the most practical fix — every unit saved is real abatement