A government has £2 000 000 for a programme to reduce carbon dioxide emissions from the energy used by buildings it owns. There are enough eligible buildings to use the full budget whichever plan is chosen.
The government is considering two plans.
| Plan | Change made to each building | Cost per building | Annual decrease in carbon dioxide emissions per building |
|---|---|---|---|
| A | Improve the energy efficiency of the heating system | £25 000 | 6 tonnes |
| B | Install a renewable electricity system | £40 000 | 11 tonnes |
Explain which plan the government should choose to produce the greater annual decrease in its carbon footprint without exceeding the budget.
The decreases in the table include only emissions while the buildings are being used.
Explain why the result from part (a) may not identify the plan that gives the greater reduction in carbon footprint over the full life cycle of the systems.
73 exam-style questions on AQA GCSE Chemistry 9.2 Carbon dioxide and methane as greenhouse gases, covering 9.2.1 Greenhouse gases, 9.2.2 Human activities which contribute to an increase in greenhouse gases in the, 9.2.3 Global climate change, and 9.2.4 The carbon footprint and its reduction. Each one has a worked solution and a mark scheme showing where the marks go.