Over a period, a country's GDP rose from £500bn to £600bn and its greenhouse gas emissions rose from 200 million tonnes CO2e to 210 million tonnes CO2e. Which of the following correctly describes what happened?

Correct answer: D) Emissions intensity fell by 12.5%, which is relative decoupling only

Explanation

Emissions intensity was 200/500 = 0.40 Mt per £bn at the start and 210/600 = 0.35 Mt per £bn at the end. The fall is (0.40 - 0.35) / 0.40 = 12.5% (rounded to one decimal place). Because total emissions still rose, this is relative decoupling; absolute decoupling would require emissions to fall in total while GDP grows. The 5.0% figure is the rise in absolute emissions and 20.0% is the rise in GDP, not the change in intensity.