A carbon footprint is the total amount of greenhouse gases emitted by something. That might be a person’s lifestyle, a product’s supply chain, an organisation, or an activity. Everything from a banana to a ship has a carbon footprint. In simple terms, it equates to the environmental impact that someone or something has.
To begin with, this term referred to just the carbon dioxide (CO₂) emissions being released into the atmosphere. CO₂ is the most common greenhouse gas. But it’s not the only one. There are other gases that contribute substantially to climate change, such as methane and nitrous oxide. Carbon footprints usually now incorporate those too.
That footprint can be reduced by buying more stuff second hand rather than new, lowering the temperature on the thermostat in a house by a couple of degrees and composting much more of food waste at home, or perhaps switching to an ethical bank that doesn’t invest in fossil fuels.
The carbon footprint concept stems from the life-cycle assessment, a way to measure the impact of a product or system over its entire lifetime. From the sourcing of raw materials to manufacturing processes, transport, and distribution, plus the energy used to dispose of a product once its no longer needed.
Measuring your carbon footprint is an important first step (forgive the pun) to improve our carbon literacy and environmental awareness. Knowing that baseline is crucial. Only then can progress really be quantified as time goes on.
Marcelle McManus, a professor of energy and environmental engineering at the University of Bath highlights “In a world where just 100 companies are responsible for 71% of global emissions,” McManus says, “we need a total overhaul of the carbon-intensive systems around us instead.”