Carbon Footprint: What It Is and How to Calculate It

The carbon footprint measures CO₂-equivalent emissions linked to our activities. Learn how to calculate it and the most effective actions to reduce it.

What is a carbon footprint

The carbon footprint is the total measure of greenhouse gas emissions generated directly or indirectly by an individual, organisation, or product, expressed in tonnes of CO₂ equivalent (tCO₂e). The "CO₂ equivalent" allows different gases (methane, nitrous oxide, HFCs, etc.) to be compared in terms of their climate impact relative to CO₂.

The main sources for an individual

  • Diet: red meat production is among the most impactful (~2 tCO₂e/year for heavy consumers)
  • Transport: a long-haul flight can emit 1–3 tCO₂e per passenger
  • Home energy: heating with natural gas, electricity from fossil sources
  • Purchases: production of consumer goods, clothing, electronics
  • Financial services: investments in fossil fuel funds have a significant footprint often overlooked

How it is measured

Personal footprint calculations are based on emission factors: average values that associate an amount of CO₂e with each activity. For example, burning 1 litre of petrol emits about 2.31 kg of CO₂. Driving 100 km with a consumption of 7 litres/100 km emits about 16.2 kg of CO₂.

Average footprint and global targets

Italy's per-capita footprint is about 6–7 tCO₂e/year, in line with the European average. To limit global warming to 1.5°C under the Paris Agreement, the global per-capita footprint should fall to about 2–2.5 tCO₂e by 2050.

The most effective actions to reduce it

  • Reduce flights (especially long-haul): enormous impact per flight
  • Switch to an electric or hybrid car, or use public transport
  • Reduce consumption of red meat and dairy (plant-based diet)
  • Home energy efficiency: insulation, windows, heat pumps
  • Choose a 100% certified renewable energy provider