Editorial Feature

How Do I Calculate My Carbon Footprint?

Dec 17 2007

Image Credits: Olivier Le Moal/shutterstock.com

The level of carbon dioxide released into the atmosphere accumulates quickly through everyday actions such as driving a car or leaving a light on. Individuals and organizations should take the initiative to calculate their carbon footprint and examine ways to reduce and/or eliminate carbon dioxide emissions

Reasons for Calculating the Carbon footprint

There are two principal reasons why an individual or organization should look to calculate their carbon footprint. The first reason is to aid in the management of the carbon footprint and reduction of the emissions over time, and the second is to create an accurate report of the carbon footprint to a relevant third party.

Management of Emissions Through Carbon Footprint

Calculating an organization's carbon footprint is an effective way of implementing systems for ongoing management of energy and the environment. It is enough to quantify and understand the key emission sources by means of a basic process that typically includes gas, electricity, and transport if this is the main cause for an organization requesting a carbon footprint.

Once the emissions have been quantified, prioritization and identification of opportunities for reduction should take place. Individuals and companies should concentrate on regions which have the greatest saving potential.

Accurate Reporting of Carbon Footprint

There is a growing need for organizations to calculate their carbon footprint in detail and to disclose their findings to the public. Several reasons include:

Corporate social responsibility (CSR) or for marketing purposes
Fulfillment of requests from retail customers, investors, or businesses
Discovering what level of emissions the organization needs to offset to become carbon neutral.

Calculating a Carbon Footprint

Calculating one’s basic carbon footprint is a fairly simple exercise. Direct emissions and emissions from electricity are likely to be covered in a basic footprint as they are the simplest to manage.

A handful of important sources of emissions must be quantified:

Onsite usage of electricity
Onsite usage of fuel
Use of transport that an individual or organization owns

Collecting key information from all utility meters and the distance traveled by organization's vehicles are needed to calculate a basic carbon footprint. Gas and electricity consumption data collected can be expressed as megawatt hour (MWh) or kilowatt hour (kWh). Other fuel data can be gathered in several units like kWh, megajoule (MJ), or liters. In the case of emissions from transport, it may be necessary to assume the total fuel consumption based on the distance traveled.

Data on the consumption of energy can be converted into equivalent carbon dioxide emissions data using standard emissions factors. These emission factors are readily available from website such as the Carbon Trust. Other greenhouse gas emissions must be converted into equivalent emissions data, which are also available from the Carbon Trust website. More complex calculations may be needed for other emission sources.

Sources from indirect emissions like emissions from waste, from employee travel on public transport and airlines, and from the chain of supply are excluded from the calculation of a basic carbon footprint.

It is possible to take appropriate measures to manage the emissions once the basic carbon footprint has been established. For example, setting emission reduction targets, identifying likely opportunities for emission reduction, and monitoring the performance of the actions taken and improvements, if needed.

Producing a Full Carbon Footprint

A more detailed approach is required for an accurate calculation of a full carbon footprint. The following five-step systematic approach can be used to produce an accurate carbon footprint: