Skip to main content
Printable page generated Thursday, 25 July 2024, 7:11 AM
Use 'Print preview' to check the number of pages and printer settings.
Print functionality varies between browsers.
Unless otherwise stated, copyright © 2024 The Open University, all rights reserved.
Printable page generated Thursday, 25 July 2024, 7:11 AM

Reducing the carbon footprint of the place where I work


This unit seeks to identify a workplace’s impact on global climate change through its emissions of greenhouse gases (GHGs), notably carbon dioxide (CO2), the most common such gas. It will then provide some guidance on how best to reduce that footprint, looking in turn at behavioural and management issues, relatively straightforward physical measures and transport.

Unit authored by Ian Byrne.

Learning outcomes

By the end of this unit you should be able to:

  • find out what carbon footprints are in a work environment;

  • understand the differing scopes for work-based carbon footprints and discover how they can be calculated;

  • identify the main areas of action and how to draw up an implementation plan.

1 Defining a carbon footprint

1.1 Why carbon?

A carbon footprint is a measure of how much an organisation is contributing to the greenhouse gases (GHGs) that cause global climate change. There are six main groups of GHGs: carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6). All of these GHGs can arise from industrial processes, although most smaller companies are only responsible for carbon dioxide, which is produced whenever fossil fuels (coal, oil and gas) are burned, generally from the direct or indirect use of energy. For this reason, other GHG emissions are normally converted into a figure for tonnes of carbon dioxide equivalent (tCO2e). Although – perhaps confusingly – we talk about a ‘carbon footprint’, it would be more accurate to talk about a ‘carbon dioxide footprint’. In this unit we talk interchangeably about carbon emissions, carbon dioxide emissions or CO2 emissions and often just use ‘energy’.

The five industrial gases are all more powerful contributors to global climate change than CO2. For example, a kilogram of the refrigerant gas HFC-134 has the same global warming potential as a tonne of carbon dioxide, and some gases – notably SF6 and the perfluorocarbons – are even more damaging. However, most gases are only used under carefully controlled circumstances, so this unit will focus mainly on carbon dioxide as it is by far the most common (and important) contributor to climate change.

1.2 What is to be measured – the boundary

Before calculating a carbon footprint, you need to decide exactly which parts of the organisation are being measured. For limited companies, it is often best to define the boundaries as being that company; for public institutions, a building- or site-based approach may be more helpful. However, if you are a tenant of an office block with common services (heating, air conditioning), it may be better to try to agree with other tenants to calculate a carbon footprint for the entire building. And if you are working for a company, do you want to bring in the carbon footprint of subsidiary companies or a share of affiliates’ energy use (and footprints)? In truth, it does not matter too much how you choose to set the boundaries: it is more important that you are consistent in your choice, so that you can measure changes to emissions over time; and it is best to concentrate on that part of the organisation over which you have some influence. Beware of adding together disparate activities that may make it hard to interpret the results: for example, if your business both manufactures a product and runs a chain of shops selling that product, it may be better to keep the two activities separate.

The Greenhouse Gas Protocol Initiative website has information about tools for calculating greenhouse gases.

The UK government’s Department for the Environment, Food and Rural Affairs (DEFRA) gives environmental reporting guidelines to help businesses convert existing data sources (e.g. utility bills, car mileage, refrigeration and fuel consumption) into CO2-equivalent emissions by applying relevant conversion factors (e.g. calorific values, emission factors, oxidation factors).

Activity 1

How much influence do you have over your organisation? Setting the boundaries to include only areas under your direct influence may lead to substantial parts not being assessed. Are there other parts of the organisation that can be brought into the process?

1.3 What is to be measured – the scope

Having set the boundary of a carbon footprint for your organisation, you now need to set the scope. Although it sounds similar, the scope means looking at which emissions within (or attributable to) the organisation need to be counted. For global reporting and many carbon trading purposes, there are three internationally recognised scopes. For practical purposes, in trying to manage your organisation’s carbon footprint, it is often easier to select a different scope.

The internationally recognised scopes, as set out in ISO 17064 (on the measurement of greenhouse gases) or the Greenhouse Gas Protocol for example, are as follows.

Scope 1: Direct emissions

  • CO2 from burning fossil fuels on site

  • CO2 from owned transport

  • Emissions arising from industrial processes (all gases)

  • Fugitive emissions (e.g. of refrigerants or methane leakages)

Scope 2: Indirect emissions (from utilities)

  • Emissions attributable to purchased electricity, heat and steam

Scope 3: Other indirect emissions

  • Transport and travel

  • Transport of products and raw materials

  • Commuting travel for employees

  • Waste disposal (can include methane from landfill)

  • Franchisees, outsourced activities (e.g. call centres) and leased assets

  • Energy embodied in bought-in materials

  • Energy from the use of products or services by customers

However, for practical purposes, it is often easier to consider just emissions under the direct control of the organisation. These may be seen as at two levels:

  • energy use, including own combustion, electricity, heat and steam, and own transport emissions

  • as before, but also including business transport and travel, plus fugitive and business process emissions.

These two levels are broadly in line with those defined by the Carbon Trust Standard.

1.4 Making the calculations

Having defined the boundary and the scope, the next step is to add numbers to them. If there are accurate utility bills (including transport fuel records and employee travel claims), it is easy enough to put them on a spreadsheet, and to convert energy (or other emissions) into carbon dioxide equivalents. In the UK, DEFRA provides an annual update on emissions factors as part of its environmental reporting guidelines. There are even a few websites that will allow you to input the data and convert it automatically to tCO2e. However, you may want to apply more specific factors to your organisation: for example, you may have more accurate estimates of car fuel efficiencies based on the actual models driven by staff.

At the end of the process, you should end up with a figure for a carbon footprint, in terms of tonnes of CO2 equivalent. Although that may tell you what your contribution to global climate change has been, it is not very useful on its own. You will need to have something to measure this against: a baseline or a benchmark. A baseline is simply the same information for an earlier period of time – this is useful for monitoring your own performance, and how you are improving (or not). You will probably need to normalise the data to account for changes in the level of activities of your organisation. This can be done by converting the total CO2 figure to relative indicators – typical examples include CO2 per tonne of product manufactured, per square metre of office space occupied, per employee or per bed-night (for a hotel or a hospital). If the nature of your organisation’s activities has changed, it is sometimes necessary to convert the data to an indicator of carbon intensity – measuring CO2 per £ of turnover. You may also want to make adjustments for external factors such as weather compensation using a technique based on adjusting for ‘degree-days’.

Carbon indicators also allow comparison with other organisations through benchmarks. These may be publicly available, from the government or bodies such as the Chartered Institute of Building Services Engineers (CIBSE). Good benchmarks should take into account the type and function of the building you are occupying, or the industrial processes that are carried out. Sometimes benchmarks are calculated in energy use and will need converting to tCO2e.

Web-based resources for calculating your carbon footprint

Web-based carbon calculators are available from:

  • National Energy Foundation

  • Carbon Trust

The Carbon Trust Standard includes a link to a free downloadable carbon footprint spreadsheet.

VESMA provides information about degree days and a whole host of other useful information about energy managemenmt in companies.

You can calculate your own degree days based on your local weather station.

The Energy Consumption Guide to Energy Use in Offices includes lots of information about benchmarks.

A summary document from Imperial College draws together the most commonly used building energy benchmarks.

Activity 2

This section is possibly the most technical one in this unit, but it is necessary to be quite sure about what emissions your organisation is responsible for, before attempting to take action to reduce them.

Carbon calculations are increasingly driven by internationally set standards, as emissions – and the projected impacts of climate change – know no boundaries. Some were initially designed to permit carbon trading under the Kyoto Protocol, the so-called ‘clean development mechanism’, or under the EU Emissions Trading Scheme (ETS), but these tend to apply only to large companies with significant resources.

As over 95% of British businesses are small or medium enterprises (SMEs), do you think that enough is being done to help them tackle their carbon footprints?

Is it inevitable that much of the work appears to be driven by reporting needs, rather than a spontaneous interest in carbon saving?

Finally, Scope 3 asks companies to consider the carbon from energy use (or savings) of their products in practice. Try to list some products where energy in use exceeds (or is dwarfed by) energy used in their manufacturing.

2 Taking action – energy management systems

2.1 The need to monitor energy use

In this section we look almost entirely at energy, as it is the main contributor to CO2 emissions, either directly (through burning fuels on site or in vehicles) or indirectly (through purchasing electricity, heat or steam that has come from fossil-fuel sources).

‘If you don’t measure it, you can’t manage it’ sums up the first stage of good energy management – as a prerequisite you need to monitor and report energy consumption on a regular and timely basis. This is not quite the same as calculating your carbon footprint – that may be done on an annual basis; energy needs to be monitored monthly, weekly or daily (or per batch of product) if it is to be effectively controlled. This process is known as monitoring and targeting (M&T). Plotting energy use on a regular time series allows small variations in demand to be seen more clearly – and a cusum (cumulative sum of differences) chart can be used to plot variations against average consumption, normalised for production volumes or temperature differences.

You can see some real-life examples of cusum charts in this slide show.

2.2 Appointing an energy manager

The question arises ‘Who will do this?’ Effective energy management needs a designated energy manager. This could be you – if no one else is currently identified, it is allowable to appoint yourself! In manufacturing companies, it is often someone from the production side. In other organisations, it may be a senior person in the finance function – accountants often enjoy telling people they have to use less energy (as well as saving money by doing so)! However, the energy manager should be a good communicator and motivator, and should also be comfortable presenting findings and recommendations to top management.

2.3 Developing an energy management system

Larger companies should implement a formal energy management system. This may be structured along the same lines as an ISO 9001 quality management system – indeed, since July 2009 there has been a British Standard (BS EN 16001) for energy management.

This works on the principle of: Plan–Do–Check–Act.

Planning includes setting a board energy policy and doing energy audits, if necessary. The next stage focuses on implementing both physical measures and encouraging behaviour change. It is then necessary to monitor the outcomes and, if necessary, to take corrective action. Finally, there is the feedback loop step – reporting to senior management, adjusting policies and plans, and setting new targets. This approach can be used even in the smallest organisations, although formal systems tend to be officially adopted only in larger ones.

You should consider drawing up a formal implementation plan. In smaller organisations this could simply be a list of bullet points, with associated costs (if any), the name of the person responsible and the target date for completion. Don’t assume that you will need a large budget. In the next two sections we look at mainly low cost or free measures. Moreover, higher cost measures will tend not to be done as ‘energy efficiency’ or ‘carbon management’ actions, but as part of larger projects, such as building refurbishment or updating production processes. In many ways it is better not to have an energy efficiency budget in a silo by itself, but to insist that the energy and carbon impact is calculated on all major purchases – whether of capital equipment or larger revenue items such as the annual travel budget.

Finally, it is necessary to evaluate the actions and report back to senior managers or the board. Try to get this built into regular reporting structures; again, a silo mentality can lead to carbon reductions being marginalised and seen as being a special interest rather than a fundamental component of the organisation’s business. (Working with the accountants to integrate this with financial reporting can again prove helpful here.)

The following are two examples of businesses reducing their energy use:

  • Five steps to effective energy management from the South West Development Agency.

  • Enworks explains how it has improved the energy efficiency of companies in North West England for which it won an Ashden Award for Sustainable Energy in 2007.

Activity 3

Good energy management is perhaps like a good wine – you know when you have it, but it is quite difficult to define in the abstract. Some people find the formal management structure (and language) associated with standards such as ISO 9001, ISO 14001 (the Environmental Management Standards) and EN 16001 unhelpful. They prefer a more person-centred informal approach, offering flexibility and rapid responses. Which approach would work better for your organisation?

3 Taking action – some easier measures

In this section we look at low budget items, with an emphasis on those most widely used in shops or smaller offices. We consider in turn heating, lighting and equipment, which are the three largest energy users in non-manufacturing companies.

3.1 Heating

Smaller shops and offices often have heating systems similar to large domestic units. They are typically based around a gas or an oil boiler feeding radiators or a warm air system. As at home, it is important that you ensure the boiler is serviced regularly to keep it in peak operating condition. New boilers should always be high efficiency condensing models. Larger systems may benefit from installing burner controls that improve the efficiency of boilers and minimise emissions by optimising the firing range. If there is more than one boiler, ensure that proper sequence controls are in place, to stop them running simultaneously at low loads.

Controls are also important: for cellular offices, thermostatic radiator control valves are essential, as some rooms heat up much more quickly than others because of the equipment inside them. Systems should be programmable to match occupancy patterns, which may run for five, six or seven days a week. Large buildings can benefit from a full Building Energy Management System (BEMS) with several heating zones. Where there is air conditioning but windows can also be opened, encourage staff to use natural rather than artificial ventilation. Entrances to shops may benefit from air curtains; warehouses or store areas can benefit from moveable warehouse curtain dividers that limit heated areas to those in use.

3.2 Insulation

Of course, there is little point in installing an efficient heating system in a poorly insulated building. You probably have at least 150 mm (and possibly 270 mm) of loft insulation at home but many older commercial buildings have very little at all. It is also often possible to fill cavity walls or add additional internal insulation (at little extra cost) when a building is being refurbished.

3.3 Hot water

The demand for hot water tends to be relatively low except in hotels, restaurants and medical facilities. For this reason, it may be better to install a separate hot water system that runs yearround, rather than take the supply off the main heating boilers. In organisations with higher use, solar water-heating panels can also be considered, which may give a faster financial return than in domestic installations.

3.4 Lighting

Lighting is important for most non-domestic applications, and is often kept on during daylight hours of occupation. For this reason (and for lower maintenance costs), high efficiency lights are vital; consider using high reflectivity luminaires, T5 tubes, LED lights and concentrated fluorescent spot lights, as well as the more commonly seen compact fluorescent lights (CFLs). Motion sensors that switch off lights in unoccupied areas can also lead to substantial savings. Try to avoid using low voltage halogen lights in display units; they are quite inefficient and generate a lot of surplus heat that may be difficult to lose.

External lighting – including security lighting – can also add a surprising amount to your organisation’s carbon footprint. Make sure mercury discharge or tungsten filament external lights are replaced by lower energy metal halide (SON) or multiple fluorescent lights. And consider whether all lights need to be left on all night for security purposes in areas such as car parks – concentrate on lights in areas at risk from vandalism or illuminating areas observed by security cameras.

3.5 Computers and office equipment

Equipment energy usage varies enormously by type of organisation, but most will have some personal computers (PCs). If you have a network, see whether you can install polling software that will automatically switch off machines that are not in use overnight. If you have a network manager, make sure that they enable power-saving features; many computers are supplied with that facility disabled.

Office equipment should be specified to at least Energy Star standards, but these are often not very high and relate more to energy consumption when on standby rather than when in use. Ensure that equipment such as coffee machines, water coolers (do you really need these anyway?) and photocopiers run on a time clock; if they don’t have one, you can usually fit a timer plug at the mains socket.

There are far too many opportunities for relatively low-cost improvements in industrial applications to list here. However, it is worth knowing that much industrial energy is used in electric motors – not only in visible locations but also inside compressors, pumps, etc. Replacing standard motors with variable speed drives is often the first place to start. Even rewound motors will sometimes save significant levels of energy – and carbon – compared with their predecessors.

3.6 Catering

Catering is another area to focus on, especially if you are in the hospitality industry or have a canteen. If you use contract caterers, check that they have an incentive to save energy, as otherwise they won’t bother and will leave you to pick up the bill. For example, try asking the chef not to switch on all the cooker rings on their arrival at 8 a.m. when the first meals don’t need to be served until midday!

Most of the above measures can be taken in leased properties without the landlord’s permission. Some of the larger improvements to heating systems or insulation may need approval, but this should often be given willingly as it could add to the value of the property, with no outlay to the ultimate owner. It is also always worth checking if there are grants or tax relief (Enhanced Capital Allowances) for actions, for example under the government’s Energy Technology List.

Web-based resources

You may find some of the following resources useful.

  • British Gas’s interactive online Energy Savers Report for businesses.

  • Eon’s Energy Marshal website also includes tools for reducing non-domestic energy use, with a focus on the people side.

  • How Green IT saves money and energy, improves image and the environment (a 14-minute video).

  • A website explaining the UK government’s Enhanced Capital Allowance (ECA) scheme, including the searchable Energy Technology List.

  • Szencorp’s headquarters at 40 Albert Road in Melbourne, Australia was once a typical energy and water-hungry building. Now it is one of Australia’s highest rated green buildings, saving 70% on its energy use.

Activity 4

This section was something of a list of possibilities. However, it cannot be exhaustive and there are often opportunities to be more innovative. The key constraint is usually the budget.

  • How easy will it be to convince your finance director of the benefits of saving carbon?

  • How much will he or she rely on strictly financial measures, such as payback or net present value?

  • Will externalities (hidden costs borne more broadly by society) be allowable?

4 Taking action – transport and behavioural change

4.1 Behavioural change

Although physical measures are important, many organisations can also save significant amounts of energy, and so reduce their carbon emissions, by encouraging employees to change their behaviour.

Top-down energy-saving campaigns may have some benefit but they tend to suffer from a general reluctance by employees to be ‘preached to’ by management. However, regular information, using data supplied by the energy manager or team leaders, can help explain the reason for management’s focus on energy, and can also be used to create an element of competition between teams, departments or sites in a single organisation. ‘Grassroots’ action, with employees deciding how to save energy themselves, can be remarkably effective, especially in manufacturing environments where managers can overlook inefficient practices. You will need to consider what would work best in your organisation: this depends as much on its internal culture as on the opportunities for saving energy or cutting carbon emissions. However, as a general rule, it is best to try to actively involve as many staff as possible.

Simple measures that can be targeted include switching off lights or computer screens when they are not in use; ensuring that staff kettles are not just filled up at the start of the day and then fully reboiled for every cup of coffee; checking that timers are enabled on photocopiers and similar equipment; ensuring that thermostats are set correctly; and making regular inspections for leaks in plant using steam, hot water or compressed air.

You may find the following resources helpful:

  • Guide to Employee Engagement to save carbon emissions from the Energy Saving Trust (a downloadable PDF document).

  • Logicity is a computer game set in a 3D virtual city. It has five main activities, including one where you are set the task of finding and switching off unnecessary equipment in a high-energy office and another exploring a low-energy office.

4.2 Working from home and teleworking

Working from home, or teleworking, is often quoted as being a way of reducing commuting and so cutting CO2 emissions. However, there are only a relatively few jobs that can be done as well at home as in a communal office. Some of the people promoting teleworking appear to have a vested interest; before taking credit for reduced travel emissions, it is also important to consider whether it may mean a house being heated all day in winter, with significantly larger emissions from that source. If you do encourage teleworking, you will need to ensure that the employee’s home has a proper risk assessment and meets health and safety requirements.

Web-based resources

The advantages and disadvantages of teleworking are explained by European Telework Online (ETO).

4.3 Business travel

In non-manufacturing companies, employees’ travel to work is often a major source of carbon emissions, whether or not you choose to include them in your carbon footprint. Even smaller organisations can draw up a travel plan. This may include encouraging car sharing, providing information about public transport services (and, for larger bodies, negotiating with bus companies to facilitate employee use) and ensuring that there are facilities for cyclists such as secure cycle racks and showers. Alternatively, you may prefer to offer incentives such as free bacon butties for employees who cycle or walk to work!

Apart from commuting, business travel is an important area of energy use. Free petrol for employees’ private motoring has now been largely taxed out of existence, but there is still evidence that company cars encourage greater private use, including longer commutes (as well as discouraging lower carbon options such as train travel while on business). Look at the mileage rates for business travel – are they higher than they need to be, and are there hidden issues such as an insurance policy that discourages employees sharing a car when driving to meetings? Also, do you pay for cyclists’ business mileage? HM Revenue and Customs allows up to 20p per mile to be paid tax-free.

It may also be possible to replace physical meetings with video conferencing. This is particularly true for international meetings when air travel can be avoided; again, try using a carbon calculator to see the immediate benefit. Of course, there are some downsides to the lack of personal contact, but how great a carbon cost can these justify? Large companies can use video conferencing, but this could just as easily be done by small firms with a webcam using a low-cost tool such as Skype.

For many white-collar organisations, flights are the single largest contributor to their carbon footprint. In economy class for medium-haul flights, the quoted emissions per passenger-kilometre are roughly double those of rail travel, but half that for a single occupancy petrol-driven car. However, there are additional global warming effects caused by aircraft, principally the emission of water vapour in jet exhaust at high altitude. To account for these non-CO2 climate change effects, the CO2 emissions figure needs to be multiplied by a factor in the range of 2 to 4; DEFRA recommends 1.9 but many environmentalists believe that this underestimates the effect and a factor nearer 3 should be used. Class matters too: business class travellers should double their emissions compared with those at the back of the aircraft, and first class passengers should multiply their emissions by around 3.5.

While it is not possible to avoid some overseas travel, for journeys within Northern Europe rail travel may be a viable alternative. For some short-haul flights, such as from London to Brussels or Paris, rail (Eurostar) is quicker, not least because of the shorter check-in times at international railway stations compared with airports. The same is true for many other trips between Western European capitals, where high-speed networks such as France’s TGV have slashed historical journey times. High-speed trains can be more expensive than budget airlines, but this is less pronounced for business users than leisure travellers. Even travel by rail and ferry can sometimes be competitive for meetings in locations such as the Netherlands or Ireland.

Web-based resources

The Man in Seat Sixty-One gives practical advice on alternatives to flying around Europe and further afield.

Travel Plans is a website devoted to explaining how to set up travel plans.

Activity 5

Finally, here are some questions to reflect on. Much of this unit is simply about applying common sense in a workplace environment. It is true that there is a need to define carefully what is being measured, and to apply the results consistently, but it isn’t rocket science. And yet many organisations miss easy opportunities to cut their bills and save carbon.

  • How can we improve our message to organisations about saving energy?

  • Is there a problem with jargon, or are organisations just too focused on making money (or surviving in a recession) to listen to new ideas? Or do they see saving the environment as belonging to the ‘beard and sandals brigade’ and not a matter for companies to bother about?

    It is too easy to see behavioural measures in terms of the simple instruction to ‘Switch It Off!’

  • Can you devise more subtle, positive approaches to saving energy and reducing carbon emissions that might achieve a higher buy-in from fellow employees?

  • Will staff who have grown used to attending boozy conferences welcome being told that they should teleconference instead?

  • How can you share information with other organisations when running the risk of being accused of anti-competitive behaviour (or of risking loss of confidentiality)?

  • Which energy-saving techniques apply to almost all organisations, and which are best used in large ones?


The links (URLs) to third party sites in these units are provided for ease of access only and The Open University does not authorise any acts which may breach any third party rights, including copyright. You should abide by any terms and conditions on any third party sites which you visit from this site. The Open University does not guarantee the accuracy of any linked materials, nor does the Open University endorse any products which may be advertised on third party sites. Please see Terms and Conditions.


Unit authored by Ian Byrne.

Unit image

Getty photodisc


All links accessed 30 November 2009.