Cleaner energy, greater efficiency and lower demand work together to reduce total emissions.
Lower-carbon energy reduces emissions from supply. Solar and wind generate electricity without burning fuel during operation. Other options suit different places. Reliable supply still needs suitable resources, storage and transmission. Materials and land use also have environmental costs.
Efficiency reduces the energy needed for a service. Efficient motors, lighting, buildings and public transport can use less energy. Electrification replaces fuel-burning equipment with electric versions; its benefit grows as electricity becomes lower-carbon. Carbon capture may reduce emissions from difficult industrial processes, but costs, energy use, capture rates and lasting storage limit it.
Efficiency alone does not guarantee lower total emissions. If energy use per product falls but enough extra products are made, overall use can rise. Cheaper operation can also encourage more use. Check both emissions per unit and total emissions, alongside changes in supply and demand.
Barriers affect whether measures are adopted and work well. Technological barriers include variable wind or solar output, grid limits and maintenance skills. Economic barriers include upfront costs and access to finance. Social barriers include affordability, acceptance and habits. Institutional barriers include weak standards and poor coordination. For each, explain how it blocks the intended reduction.
Step by step
Change the supply
Lower-carbon energy reduces emissions from producing electricity.
Use energy efficiently
Better equipment and design need less energy for the same service.
Check the total
Rising production or demand can outweigh savings per unit.
Worked example: An electric bus needs a system explanation
Replacing a diesel bus with an electric one removes tailpipe emissions. Its wider climate benefit depends on electricity generation, vehicle manufacture, service use and which journeys it replaces. Combining clean power with well-used public transport strengthens the mitigation case.
Watch out for this
A lower emissions intensity guarantees lower total emissions.
Total emissions also depend on the amount produced or consumed. Calculate both.
Check your understanding
A factory cuts emissions per product from 2 to 1.5 units but increases output from 100 to 160 products. What happened to total emissions?
- They fell to 150 units.
- They rose from 200 to 240 units.
- They became zero because efficiency improved.