In addition to metrics like ecological footprint, each of us (and each of the products and services we use and consume every day) has a carbon footprint; it’s a way to measure the relative impact of our actions — as individuals, as businesses, communities and countries, as we eat, work, travel, play, etc. — in terms of the contribution made to global climate change.
Measured in carbon emissions (usually in pounds, tons or kilograms), it’s become an increasingly useful and popular tool to help contextualize global warming in our daily routines and lives. What is a carbon footprint?
A carbon footprint is the total amount of carbon dioxide (CO2) and other greenhouse gases emitted over the full life cycle of a product or service, and everything has one, from the computer you used to find this article to the next meal you eat (and the one after that, and after that, and so on…) to the shoe that will leave a physical footprint on the ground the next time you walk outside. But that’s only part of the story.
Calculating carbon footprints
First of all, carbon footprints can be calculated in one of two ways: using a Life Cycle Assessment (LCA) method (more accurate and specific), or it can be restricted to the immediately attributable emissions from energy use of fossil fuels (more general). To use your car’s carbon footprint as an example: the first method would take into account all carbon emissions required to build the car (including all the metal, plastic, glass and other materials), drive the car and dispose of the car; the second would account only for the fossil fuels that resulted from building, driving and disposing of it.
Further, there’s more than one way to run the numbers, depending on how they’re going to be used. Top-down calculations, , that calculate per capita carbon footprints, take total emissions from a country (or other high-level group, organization, etc.) and divide these emissions among the residents or otherwise applicable group. Bottom-up calculations, like with your car’s carbon emissions from the example above, sum attributable carbon emissions from individual actions.
But it’s not just about the carbon –
Okay, so everything has a carbon footprint, and each can be measured a couple different ways, but it’s not just a matter of carbon dioxide, though that is the most common of greenhouse gases (GHGs) other than water vapor; other GHGs include (but aren’t limited to) methane, ozone, nitrous oxide, sulfur hexafluoride, hydrofluorocarbons, perfluorocarbons and chlorofluorocarbons (see the IPCC list of greenhouse gases for a more thorough list).
Given this, still, most carbon footprint calculations include all applicable gases, as they all contribute to the greenhouse effect and our persistently warming globe.
“What is my carbon footprint?” Calculating your own footprint
Though a fairly complex calculation, with many variables that are different for each person, carbon footprint calculations generally include energy used to power our homes and transport, including travel by car, airplane, rail and other public transport, as well as all the consumables we use on a regular (and irregular) basis; many of the individual factors above can be calculated separately (e.g. an individual carbon footprint for your home, travel, food, etc.).
Once you understand what goes in to your carbon footprint, and, probably more importantly, what your carbon footprint is, you can start reducing it; indeed, for as many ways as there are to create a carbon footprint, there are ways to reduce it.
Reducing your carbon footprint
Increasing the efficiency of our energy use, reducing our energy use and changing a few habits (like eating less meat, eating more local food, not traveling by airplane as much) are some of the quick, easy ways to cut back on the size our individual carbon footprints.
Where do carbon offsets fit in carbon footprints?
After increasing efficiency and reducing use, carbon offsets are also an increasingly popular (and increasingly controversial) way to help mitigate our carbon footprints — see TreeHugger’s How to Green Your Carbon Offsets guide for more on that. But the point remains: there are many, many ways to reduce and even eliminate your carbon footprint; most every article you’ll read on TreeHugger will be related to carbon footprints and emissions, though some more directly than others.
Moving forward, we expect to see more and more information about the carbon footprints of the things we encounter and use every day; carbon labeling for produce is catching on the UK, and we’ve seen carbon footprint measurements for everything from cheeseburgers to Christmas, and sushi to Shaq.