Methane from rotting waste escapes from a landfill site. A gas-collection system was installed at the site.
The table shows the mass of methane that escaped into the atmosphere in one year.
| Measurement | Mass of methane in tonnes |
|---|---|
| Before the system was installed | 18.0 |
| After the system was installed | 6.3 |
Calculate the percentage decrease in the mass of methane that escaped into the atmosphere. Explain why this decrease is likely to reduce global warming.
84 exam-style questions on AQA GCSE Biology 7.3 Biodiversity and the effect of human interaction on ecosystems, covering 7.3.1 Biodiversity, 7.3.2 Waste management, 7.3.3 Land use, 7.3.4 Deforestation, 7.3.5 Global warming, and 7.3.6 Maintaining biodiversity. Each one has a worked solution and a mark scheme showing where the marks go.