Environmental sustainability is a measure of an organization’s impact on the health of the planet. Over the past few decades, the practice of measuring environmental sustainability has evolved greatly around the world. Organizations of different kinds have contributed to the development of systems and tools, standardized approaches and techniques, methods of recognition and educational programming. The field continues to expand based on a constantly expanding public and private interest in measuring environmental sustainability.
Life Cycle Assessment
Virtually everything related to an organization’s operation has an impact on the environment. That is one of the most basic principles related to measuring environmental impact that is not often clearly understood. For the sake of clarity, we define environmental impact as “any change to the environment, whether adverse or beneficial, resulting from an organization’s activities, products or services.”1 Whether it be a delivery vehicle, the furnishings used to decorate an office, or the accounting company hired to help with tax season, each has an environmental impact. While a vehicle’s impact may be more obvious, you may ask what a chair on wheels or chartered accountant named Phil have to do with the environment?
Life Cycle Assessment (LCA), also referred to as life cycle analysis and accounting, is a technique used to assess environmental impacts associated with all the stages of a product or service’s life. That includes any related extraction of raw materials, materials processing, manufacturing, distribution, use, repair and maintenance, and disposal or recycling. In more closely examining the delivery vehicle previously mentioned, environmental impact is not limited to the fuel consumed: it includes the impact of extracting and developing all of the materials that make up the vehicle, the resources used in manufacturing the vehicle itself, and so forth. In other words, the fuel consumed represents only a fraction of the impact of the delivery vehicle.
As another example, the new office chair for the accountant doesn’t produce emissions during its use, but it certainly required raw materials, production, transport, and, eventually, disposal. All these related impacts should be captured by LCA.
So what about Phil the accountant? His service also has a life cycle impact. While we may not explicitly count the resources used to make Phil himself, we probably would include the resources Phil uses to complete our accounting. That might include the paper, the electricity used for his computer, the impact produced by Phil’s commute to work, as well as the operation of his office.
A study done by the US Department of Energy on the life cycle impact of light bulbs shows that no matter what type of bulb (incandescent, fluorescent or LED) the majority of the impact on the environment happens while the product is in use with the impact of raw materials ranking second but far behind. The other three stages of impact, from largest to smallest, are manufacturing, disposal then transportation, which makes a negligible impact compared to the other stages.
On the opposite side of the spectrum, a study conducted by the National Electrical Manufacturers Association on the life cycle assessment of alkaline batteries shows that there is zero impact during use because any emissions to air, land or soil in the use of a battery in a product would be a result of the product. The greatest impact comes from the materials used followed by manufacturing, transportation and disposal in order.
To learn more about Life Cycle Assessment and how it can help your organization measure its environmental impact click here
For a free tool to help your organization assess the life cycle impact of a product or service click here
Carbon as a Measure of Environmental Impact
There are a variety of metrics that can be used to measure environmental impact; some of these include: biodiversity, air quality, land degradation and water consumed. Your organization will need to decide which metrics are best suited to effectively measuring the environmental impact it produces. Internationally, the metric that has been most consistently used to measure environmental impact is carbon dioxide.
For a guide that compares various approaches to measuring environmental impact click here
Carbon Dioxide & Greenhouse Gas Emissions
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms bonded to a single carbon atom. There is sometimes confusion around the difference between the terms carbon and carbon dioxide. Carbon as an element on its own is a non-metal material, not the gas we are concerned with. It is important to note that carbon dioxide is often shortened to just carbon for ease of reference; that abbreviation also applies to terms like carbon equivalent, carbon footprint and carbon accounting, which we will examine further ahead.2
Carbon dioxide (CO2) makes up the largest share of the planet’s greenhouse gases (GHGs). GHG emissions involve the release of greenhouse gases into the atmosphere over a period of time and are calculated by multiplying the emissions of each of the six (aforementioned) GHGs by its 100-year global warming potential. Within the Kyoto Protocol, six principal GHGs are identified: carbon dioxide, methane, nitrous oxide, sulfur hexaflouride, hydrofluorocarbons and perfluorocarbons.3
Greenhouse gases can be emitted through a variety of functions including transport, land clearance, as well as production and consumption related to: food, fuels, manufactured goods, materials, wood, roads, buildings, and services. The addition of man-made greenhouse emissions into the atmosphere disturbs the Earth’s radiative balance, leading to an increase in the Earth’s surface temperature.
Carbon as a Metric
To keep the measurement of environmental impact simple and consistent, all GHG emissions (aside from carbon dioxide) are commonly converted into carbon dioxide equivalent emissions. Carbon dioxide equivalent (CO2e) is a term used to describe different greenhouse gases in a common unit meaning, for any quantity and type of greenhouse gas, CO2e signifies the amount of CO2 which would have the equivalent global warming impact.
E.g. if 1kg of methane is emitted, this can be expressed as 25kg of CO2e (1kg CH4 * 25 = 25kg CO2e).
Essentially, CO2e is a useful term because groups of greenhouse gases can be expressed as a single number, and it allows different GHGs to be easily compared.4
This conversion is performed by applying unique carbon emission factors to various sources of environmental impact which we will refer to herein as emissions sources. Carbon emission factors are multiples used to convert a unit of measure that quantifies the size of a emissions source (e.g. kilowatt hours of energy, litres of gasoline, pounds of waste, etc.) into an equivalent amount of carbon. Carbon emission factors are representative values relating the quantity of an emission with the activity responsible for the release of that emission.
Below is an example of a formula an organization would use to calculate the carbon equivalent emissions related to 70,774,885 kilowatt hours (kWh) of electricity purchased.
kWh of Electricity Purchased × Emissions Factor = Carbon Equivalent Emissions
70,774,885 KwH × 0.00017 mtCO2e/KwH = 12,032 tCO2e
In general, the formula used to calculate carbon equivalent emissions is based on the following structure:
Quantity of Units Related to Emissions Source × Applicable Carbon Emissions Factor
= Output of Carbon Equivalent Emissions5
To learn more about the common terms associated with the measurement of GHGs click here
For a free tool to help your organization calculate the carbon dioxide equivalent of other GHGs click here
If you don't have a strong understanding of Carbon Dioxide and Greenhouse Gas Emissions, please click here before advancing.
Context for Developing Measurement Capacity
Carbon accounting, an approach to measuring environmental sustainability, refers generally to processes undertaken to “measure” amounts of carbon dioxide equivalents emitted by an entity. The Greenhouse Gas Protocol (GHGP) is an internationally recognized carbon accounting standard and has served as the basis for most any well-recognized carbon framework or guideline in the world. The GHGP was written by the World Resources Institute and the World Business Council for Sustainable Development in partnership with businesses, governments, and environmental groups around the world to build a new generation of credible and effective programs for tackling climate change. Organizations can follow the principles of the Greenhouse Gas Protocol as part of calculating the equivalent level of carbon emissions they are generating.
The GHGP is free to use and easily accessible to anyone. It is the standard most widely used by organizations as it effectively lays out ways for understanding, quantifying, and managing GHG emissions at the organizational level. The GHGP operates on a set of principles derived in part from financial accounting; these principles include relevance, completeness, consistency, transparency, and accuracy. Their application ensures the carbon accounting performed provides an honest and fair representation of an organization’s GHG emissions. The following describes details related to calculating a carbon footprint based on the definitions and details outlined in the GHGP .
To learn more about the Greenhouse Gas Protocol click here
All of the measured carbon equivalent emissions an organization produces are combined to generate a carbon footprint. A carbon footprint is more formally defined as the total greenhouse gas (GHG) emissions caused directly and indirectly by an individual, organization, event, or product and is expressed as a carbon dioxide equivalent.
The calculation of a carbon footprint and its accuracy can vary quite greatly from one organization to the next based on the methods employed. To understand why, we will first examine the difference between direct and indirect emissions and their relevance to the emission factors used.
Direct Emissions: carbon emissions originating from emission sources owned or controlled by the organization measuring its impact (e.g. the emissions created by burning the fuel used to power a vehicle).
Indirect Emissions: carbon emissions resulting from emission sources owned or controlled by another entity (e.g. all of the up and downstream impacts related to the manufacturing, distribution, disposal, etc. of a vehicle).
Some organizations rely on carbon emission factors based exclusively on direct emissions. Others rely on carbon emissions factors developed based on a Life Cycle Assessment (LCA) which considers all direct and indirect emissions. Naturally, carbon emissions factors derived from an LCA more accurately reflect the full environmental impact generated and, as such, offer better measurement data. We strongly recommend exclusively using emissions factors that are based on an LCA whenever possible.
The scope of the GHG emissions produced will also greatly affect the calculation and accuracy of a carbon footprint. All direct and indirect emissions are categorized into either Scope 1, 2 or 3 emissions.
Scope 1: all direct GHG emissions originating from: The generation of electricity, heat, or steam; physical or chemical processing; transportation of materials, products, waste, and employees; emissions resulting from intentional or unintentional releases.6
Scope 2: indirect GHG emissions originating from the consumption of purchased electricity, heat or steam.
Scope 3: other indirect emissions, such as the extraction and production of purchased materials and fuels, transport-related activities in vehicles not owned or controlled by the reporting entity, electricity-related activities (e.g. T&D losses) not covered in Scope 2, outsourced activities, waste disposal, etc.
To learn more about Scope 1, 2 and 3 refer to chapter 4, page 27-29 of the GHGP here
For a free tool that calculates the carbon dioxide equivalent of Scope 1 environmental impacts in addition to visually appealing comparisons and breakdowns click here
Emissions sources within each scope as defined by the GHG Protocol7
The above diagram shows a summary of emissions sources within each scope as defined by the GHGP broken down by Scopes 1-3. The GHGP further categorizes direct and indirect carbon emissions into three broad levels of scope: most organizations will measure Scope 1 and 2 emissions and omit Scope 3 emissions. They do this for a number of reasons, including that it can be difficult to accurately capture Scope 3 data.
With this in mind, it is not uncommon for organizations to find that the greatest environmental impacts and reduction opportunities are a function of Scope 3 emissions sources. For that reason alone, it can be challenging to fulfill on a sincere and foundational commitment to the environment without including Scope 3 emissions. Accounting for Scope 3 emissions does not necessarily demand an assessment of every possible emission source; rather, a great deal of valuable data can often be acquired by focusing on thoughtfully selected Scope 3 emissions sources. Most organizations that choose to address Scope 3 emissions will begin by including some emissions sources and adding additional sources over time.
For a free REFOCUS developed tool that helps you identify your emissions sources and what scope they fall into click here
Carbon: The Metric of Choice
With a better understanding of how carbon (equivalent emissions) is used as a metric, it is important to appreciate why it is commonly and effectively employed on its own to measure environmental impact. Resource intensive industries such as mining, agriculture, and manufacturing, for example, commonly generate a variety of direct impacts on our natural environment. Practices like the extraction of raw materials requires large amounts of water, and degrades natural habitats, impacting the environment in ways that cannot be effectively quantified using carbon dioxide equivalents alone. When a wide range of significantly sized impacts are generated, accurately measuring environmental sustainability demands looking beyond carbon and seeking sector-specific sources of impact and guidelines.
For a list of free tools that can help resource intense industries measure GHG emissions click here
Only a very limited percentage of small- and medium-sized organizations generate any significant impact that cannot be expressed as a carbon equivalent. With little need for other metrics, most small and medium organizations can responsibly employ only carbon dioxide equivalents to accurately measure impact on the environment. As such, for the purposes of this Guidebook, we will focus on measuring environmental sustainability using carbon dioxide equivalents alone.
1. Definition found in the Environmental Protection Agency’s EMS Implementation Guide for the Shipbuilding and Ship Repair Industry here: http://www.epa.gov/sectors/sectorinfo/sectorprofiles/shipbuilding/module_05.pdf
2. The State of Delaware, offers a great resource on The Greenhouse Effect found here: http://www.dnrec.delaware.gov/ClimateChange/Pages/Greenhouse%20Effect.aspx
3. Information on the six principal GHGs was on The United Nations Framework Convention on Climate Change webpage on the Kyoto Protocol here http://unfccc.int/kyoto_protocol/items/3145.php
4. Matthew Brander talks at length about Carbon Dioxide equivalents in his article Greenhouse Gases, CO2, CO2e, and Carbon: What Do All These Terms Means? Found here: http://ecometrica.com/assets//GHGs-CO2-CO2e-and-Carbon-What-Do-These-Mean-v2.1.pdf
5. Information on conversion formulae and example adapted from Environment Canada’s National Inventory Report 1990-2008: Greenhouse Gas Sources and Sinks in Canada, 2010
6. Information on Scope 1, 2 & 3 adapted from The Greenhouse Gas Protocol – A Corporate Accounting and Reporting Standard found here: http://www.ghgprotocol.org/files/ghgp/public/ghg-protocol-revised.pdf
7. The source of this diagram is chapter 4, page 26 of The Greenhouse Gas Protocol – A Corporate Accounting and Reporting Standard found here: http://www.ghgprotocol.org/files/ghgp/public/ghg-protocol-revised.pdf