AQA GCSE Chemistry (8462), Higher tier · Chemistry of the atmosphere › Carbon dioxide and methane as greenhouse gases
Practise The carbon footprint and its reduction. 12 exam-style questions on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy4 marks
(a) What is meant by the carbon footprint of a product?[1]
(b) Give two ways of reducing emissions of carbon dioxide.[2]
(c) Which action would reduce emissions of methane? Tick (✓) one box.[1]
Building more landfill sites
Driving electric cars
Eating less meat from cattle
Using more fertiliser
Show the answer and mark scheme
(a)
the total amount of carbon dioxide and other greenhouse gases emitted over the full life cycle of the product
(b)
use alternative energy sources (e.g. wind, solar, nuclear)
energy conservation (e.g. insulating homes)
carbon capture and storage
carbon taxes / licences
carbon off-setting (e.g. planting trees)
(c)Answer: Eating less meat from cattle
Question 2Medium6 marks
A government plans to reduce its country's carbon footprint by building wind farms and introducing a carbon tax.
(a) Explain how a carbon tax could reduce emissions of carbon dioxide.[2]
(b) Explain how building wind farms could reduce the country's carbon footprint.[1]
(c) Give three reasons why actions to reduce a country's carbon footprint may be limited.[3]
Show the answer and mark scheme
(a)
companies / people pay tax for the carbon dioxide they emit (or for fossil fuels they use)
so they are encouraged to use less fossil fuel / switch to low-carbon energy sources
(b)
electricity is generated without burning fossil fuels, so less carbon dioxide is emitted
(c)
scientific disagreement over the causes and consequences of global climate change
lack of public information and education
people are unwilling to change their lifestyles
economic considerations / cost (e.g. of new technology, effects on jobs)
incomplete international cooperation (other countries may not reduce their emissions)
Question 3Hard6 marks
A gas-fired power station emits 2.0 million tonnes of carbon dioxide each year. The company plans to capture 90% of the carbon dioxide and store it underground (carbon capture and storage). The company will off-set the remaining emissions by planting a forest. Each hectare of the forest will absorb 10 tonnes of carbon dioxide each year.
(a) Calculate the mass of carbon dioxide that will still be emitted each year after carbon capture and storage.[1]
(b) Calculate the area of forest needed to off-set these remaining emissions.[1]
(c) The company claims that the power station will be 'carbon neutral'. Evaluate this claim.[4]
Show the answer and mark scheme
(a)Answer: 200 000 tonnes
200 000 (tonnes) / 0.2 million (tonnes)
(b)Answer: 20 000 hectares
20 000 (hectares)
(c)
carbon neutral means no net release of carbon dioxide / emissions are balanced by removal
the plan could balance the emissions from the power station itself
young trees absorb less carbon dioxide, so it will be many years before the forest absorbs 10 tonnes per hectare
the forest could be cut down or burn, releasing the carbon dioxide again
carbon capture uses energy, so more gas must be burned
stored carbon dioxide might leak / extracting and transporting the gas also releases greenhouse gases (e.g. methane leaks)