The carbon footprint can be reduced by reducing emissions of carbon…

The idea

Because a carbon footprint is the total carbon dioxide and methane released over a full life cycle, it falls when emissions of those gases fall at any stage. Carbon dioxide emissions drop by burning less fossil fuel: using renewable electricity, improving energy efficiency, insulating buildings, switching to electric transport and choosing goods with less processing and shorter transport distances. Methane emissions drop by capturing gas from landfill and livestock waste, reducing food waste, and preventing leaks from gas pipes and coal mines. For example, generating electricity from wind instead of coal avoids carbon dioxide, while capturing methane from a landfill site stops a powerful greenhouse gas escaping. Reducing one stage helps, but the largest reduction comes from cutting emissions across the whole life cycle.

What earns the marks

• States that reducing carbon dioxide emissions lowers the carbon footprint.
• States that reducing methane emissions also lowers the carbon footprint.
• Gives a valid carbon dioxide reduction method, such as using renewable energy or improving efficiency.
• Gives a valid methane reduction method, such as capturing landfill gas or reducing food waste.
• Links the reduction to a stage of the life cycle, for example manufacture, transport or disposal.
• Recognises that both gases must be tackled because methane is a potent greenhouse gas.

Common mistakes and how to put them right

• Assuming only carbon dioxide matters.

  Put it right: Methane is a greenhouse gas and reducing it also lowers the footprint.

• Thinking recycling alone removes all emissions.

  Put it right: Recycling reduces some stages but extraction, manufacture and transport may still emit.

• Confusing reducing emissions with offsetting.

  Put it right: Planting trees absorbs carbon dioxide but does not stop the original emissions.

Exam tips

• Name the gas being reduced and the action that reduces it, so the link is explicit.
• Give one carbon dioxide method and one methane method to cover both parts of the statement.
• Avoid vague phrases such as being greener; state the specific change, such as using wind power instead of coal.