The carbon footprint measures a full life cycle
Definition
Carbon footprint
The total amount of carbon dioxide and other greenhouse gases given off over the full life cycle of a product, service or event.
Definition
Greenhouse gas
A gas in the atmosphere that absorbs infrared radiation emitted by Earth and transfers energy to the surroundings, warming the atmosphere.
- A carbon footprint is the total carbon dioxide and other greenhouse gases released over the full life cycle of a product, service or event.
- 'Full life cycle' means from making it, through using it, to disposing of it.
- A carbon footprint can be worked out for almost anything: a journey, a meal, a phone or even a festival.
Ways to reduce a carbon footprint
Definition
Energy efficiency
The proportion of the energy supplied to a device or process that is transferred usefully rather than wasted.
Definition
Photosynthesis
The process in which algae and plants use light energy to convert carbon dioxide and water into glucose, releasing oxygen.
- Use less energy through better energy efficiency and energy conservation.
- Switch to renewable and nuclear energy instead of fossil fuels.
- Capture carbon dioxide before it escapes, using carbon capture and storage.
- Offset remaining emissions, for example by planting trees that remove carbon dioxide by photosynthesis.
- Governments can add carbon taxes or licences to discourage high emissions.
Key Idea
Cutting a carbon footprint means emitting less greenhouse gas and capturing or offsetting whatever is still released.
Why cuts are harder than they look
- Low-carbon technology and changes often cost money, which some people are unwilling to pay.
- Reducing emissions needs international cooperation, which is hard to reach.
- Many people lack information or are reluctant to change their lifestyles.
- Some governments worry about the economic effects of acting.
Common Mistake
- Do not confuse reducing a carbon footprint with making it zero; most actions lower it rather than remove it.
- 'Carbon neutral' means emissions are balanced by removal, not that nothing is emitted.
Exam technique
- List several reduction methods and, where asked, a matching limitation such as cost or cooperation.
- Link 'planting trees' to photosynthesis removing carbon dioxide, not just 'trees are good'.
Self review
- What does a carbon footprint measure, and over what period?
- Give three ways to reduce a carbon footprint.
- How does planting trees help reduce a carbon footprint?
- What does 'carbon neutral' actually mean?
- Give two reasons why reducing carbon footprints is difficult.
