A carbon footprint is the total amount of greenhouse gases (including carbon dioxide and methane) generated by our actions. It is measured in tonnes of CO2 equivalent (CO2e) per year. For individuals, this includes emissions from home energy use, transport, flights, diet, and consumption of goods and services.

The average UK carbon footprint is approximately 5.2 tonnes of CO2e per person per year. This has fallen from around 15 tonnes in 1990 due to cleaner electricity and reduced industrial emissions. However, it is still well above the 2.1 tonnes target needed globally to limit warming to 1.5°C.

CO2 emissions are measured in kilograms or tonnes of carbon dioxide equivalent (CO2e). This metric converts all greenhouse gases (methane, nitrous oxide, etc.) into the equivalent warming impact of CO2 over a 100-year period. For example, 1 kg of methane equals approximately 25 kg of CO2e.

Flight emissions depend on distance and cabin class. Per passenger in economy class: a short-haul flight (e.g., London to Paris, 350km) produces around 90kg CO2e. A medium-haul flight (e.g., London to Madrid, 1,250km) produces around 320kg CO2e. A long-haul flight (e.g., London to New York, 5,500km) produces around 1,070kg CO2e.

Key ways to reduce your footprint include: 1) Switch to a renewable energy tariff or install solar panels. 2) Drive less, use public transport, cycle, or switch to an electric vehicle. 3) Reduce flights, especially long-haul. 4) Eat less meat and dairy — plant-based diets have roughly half the emissions of meat-heavy diets. 5) Buy fewer new clothes and electronics. 6) Insulate your home.

According to the Paris Agreement and the IPCC, the global target is to reach around 2.1 tonnes CO2e per person per year by 2050 to limit warming to 1.5°C. Developed nations like the UK need to reach net zero sooner, around 2045, to compensate for historical emissions. This means cutting the current UK average by roughly 60%.

A mature tree absorbs approximately 22 kg of CO2 per year. Based on this, the average UK citizen (5.2 tonnes/year) would need around 236 trees planted and maintained for a year to offset their annual emissions. However, tree planting alone is not enough — reducing emissions at source is far more effective.

No, electric cars are not zero-emission. They have zero tailpipe emissions, but emissions occur during manufacturing (especially the battery) and electricity generation. However, over their lifetime, electric cars typically produce 50-70% less CO2e than equivalent petrol cars, especially when charged with renewable electricity. The emissions gap will widen as the UK grid becomes cleaner.