1. 1
   A dairy farmer is attending a workshop on how farming practices affect the atmosphere. The workshop leader explains that cattle release a particular greenhouse gas during digestion, contributing to global warming alongside carbon dioxide.

   (a)

   Which gas is this?

   [1 mark]

   • AMethane
   • BNitrogen
   • COxygen
   • DChlorine

   (b)

   The workshop leader also explains how greenhouse gases keep the Earth warm enough to support life. Which statement correctly describes the greenhouse effect?

   [1 mark]

   • AGreenhouse gases block short wavelength radiation from reaching the Earth's surface entirely
   • BGreenhouse gases reflect all incoming sunlight back into space, cooling the Earth
   • CGreenhouse gases react chemically with oxygen to release heat directly
   • DGreenhouse gases absorb and re-emit long wavelength radiation, keeping the Earth's surface warm

   (c)

   The farmer asks the workshop leader to name two specific human activities, other than raising livestock, that increase the amount of greenhouse gases in the atmosphere, and to state which greenhouse gas each activity mainly increases.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A city council is reviewing a report on rising sea levels near a coastal town, which the report links to global climate change.

   (a)

   Which of the following is a potential effect of global climate change mentioned in such reports?

   [1 mark]

   • AAn immediate and total loss of the ozone layer
   • BA permanent decrease in the world's population of all species
   • CRising sea levels due to melting ice and thermal expansion of seawater
   • DA permanent reduction in the percentage of nitrogen in the atmosphere

   (b)

   The council report also mentions that some regions may experience more extreme and unpredictable weather patterns as a result of climate change. Which of these is also commonly listed as a potential effect of climate change in scientific reports?

   [1 mark]

   • AA guaranteed increase in crop yields in every region of the world
   • BChanges to the distribution of species and habitats
   • CA permanent decrease in average global temperature
   • DAn increase in the proportion of oxygen in the atmosphere

   (c)

   A council member is unsure how confident scientists can really be about climate change predictions, given that the future cannot be directly observed. Explain why peer review and wide communication of climate change evidence to different audiences are important parts of building confidence in scientific conclusions about climate change.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   An airline company is calculating the carbon footprint of a single long-haul flight as part of a new sustainability report for its passengers.

   (a)

   Define the term 'carbon footprint' and explain what should be included when calculating the carbon footprint of a specific product or service such as a flight.

   [3 marks]

   (b)

   The airline wants to reduce its overall carbon footprint but argues that some proposed actions, such as fully replacing all long-haul flights with electric aircraft, are not currently realistic. Describe two actions the airline could reasonably take to reduce its emissions of carbon dioxide and methane, and explain one reason why efforts to reduce carbon footprint in the airline industry may be limited.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A national government is drafting new climate policy and must explain to the public, in an accessible report, both how greenhouse gases cause global warming and why human activities are increasing the risks associated with global climate change. An opposition politician argues that the report exaggerates the risks.

   (a)

   Explain the greenhouse effect in scientific terms, describe how specific human activities have increased the concentrations of carbon dioxide and methane in the atmosphere, and discuss the scale of the risk this poses, including named potential effects on the environment and human society.

   [6 marks]

   (b)

   An opposition politician argues that the government's climate report exaggerates the risks, pointing out that scientific predictions about climate change carry some uncertainty and that reducing greenhouse gas emissions would be costly for industry and citizens. Evaluate this argument, discussing the reasons why some uncertainty exists in climate change evidence, why this uncertainty does not necessarily mean the risk should be ignored, and why actions to reduce carbon dioxide and methane emissions may nonetheless be limited in practice.

   [6 marks]

   Total for question 4: 12 marks

End of questions