The social and economic benefits of reducing crime are well understood, but the potential environmental benefits are yet to be developed fully (Pease 2009; Skudder et al. 2016). Actions taken to prevent crime are not exempt from the current global effort to reduce emissions. The aim of this study was to estimate the carbon impact of burglary prevention measures and identify those that are both low-carbon and effective. By analysing environmental declarations of commonly used burglary prevention products, we have estimated the average carbon footprint of various measures, including door and window locks, security lighting, burglar alarms and CCTV systems. This study is believed to be the first review of carbon footprint information related to burglary prevention measures.
We have highlighted that in terms of environmental impact, burglary prevention measures installed in households have relatively small carbon footprints (between 12 and 400 kg CO2e) with no individual measure exceeding the carbon footprint associated with an incidence of burglary (1000 kg CO2e). All individual measures considered produce less than half the emissions associated with a burglary, and in some cases, produced over 80 times fewer emissions than a single burglary, showing potential carbon paybacks if burglaries can be avoided by implementing these measures. Only two combinations of measures (one with five measures and one with six) exceeded the footprint of a burglary.
Of course, the desirability of these measures is subject to their effectiveness at preventing burglaries from occurring. We therefore plotted the carbon payback ratio (footprint of burglary over the footprint of the measure) alongside an effectiveness indicator (the security protection factor or SPF). When burglary prevention measures are used in isolation, window locks, indoor lighting and door locks are found to be the most desirable as they are highest on the environmental performance scale (with higher carbon payback ratios) and highest on the effectiveness scale. When combinations of measures were analysed, the most desirable combinations include window locks, door locks, indoor and external lighting (WIDE). The least desirable combinations (lower environmental performance and lower effectiveness) were those that included burglar alarms.
The way forward
The current study can be expanded in a number of ways. The availability of environmental declarations to estimate the carbon footprints is central to this work. As environmental declarations are very product specific, the results can vary considerably due to the sources of data used, the product designs or manufacturing techniques.Footnote 7 However, only comparing declarations with matching stages would vastly diminish the sample size. Where major differences between declarations in similar product groups were found, this was highlighted (see Fig. 2).
Also, as environmental declarations are costly to undertake and produce, it is likely that only ‘higher spec’ or ‘higher grade’ products generally have environmental declarations. Lower grade products may have differing environmental impacts (such as the carbon intensity of the manufacturing process), but these are difficult to estimate and so results may be biased towards representing the impacts of only higher-grade products.Footnote 8 Future work would ideally include a larger number of environmental declarations for each product type and include those of varying quality (and higher and lower prices).
This study used information from the environmental declarations to represent the carbon footprint of the installation of these products only and did not consider the embodied carbon of any products that may be replaced by newer or more secure products. In this way, we have assumed the choice between which measures to implement is at the beginning of a house design stage rather than crime prevention measures which have been retrofitted into existing homes. Incorporating carbon footprint estimates of security devices fitted in existing homes presents an additional extension of the current work.
The time period differences for SPF calculations (2008/2009–2011/2012), environmental declarations (2007–2015) and housing stock (2010) also demonstrate a further limitation (with a coincidental midpoint of 2010). The preventive effect and related SPF values of security devices and their combinations may well alter over time. This has been evident with burglar alarms, which used to prevent burglaries effectively in the period 1992–1996 (Tilley et al. 2015), unlike during the most recent years examined (2008/2009–2011/2012) in the current work. Replicating the current study for informing policy initiatives should rely on up-to-date SPF and carbon footprint estimates.
The current work gives conservative estimates for both the preventative effect and the carbon payback ratio of security measures. Our findings build on those of Tseloni et al.’s (2014), which assessed the effectiveness of these products but did not consider the carbon implications. The SPF’s indicate the preventative effect of a security device(s) for a year due to crime survey constraints. As it would be realistic to assume that burglary risks for longer than annual time windows are higher than those within a year (Wittebrood and Nieuwbeerta 2000), the SPF values arguably underestimate the preventative effect of security during a 10-year period. In addition we only compared the footprint of burglary prevention measures to the footprint of a single burglary. It is likely that once installed these measures may prevent more than one incident of burglary taking place in the course of the 10 years of the devices’ lifespan assumed here. Therefore, our study may also underestimate the level of carbon payback ratio, as the emissions associated with the consequences of two or more burglaries may be avoided.
Future research in this area could fine-tune both estimates of preventive effectiveness and carbon payback across different types of housing with due consideration also given to residing households’ plausible accessibility to burglary security deriving from income and tenure constraints and their likely burglary incidence (mean number of burglaries rather than risks) over concurrent time periods. For example, it would be realistic to assume that the carbon payback ratio is even higher than estimated herein for particularly vulnerable households, such as social renters whose burglary risk and incidence are well above average (Hunter and Tseloni 2016; Tseloni and Thompson 2015).
Decreasing the carbon footprint of burglary prevention
A natural extension of this study is to consider how to reduce the footprint of the burglary prevention measures studied. There are many ways manufacturers can reduce the embodied carbon of their products. The process of commissioning an environmental declaration that estimates environmental impacts is a good starting point, since LCAs are considered a viable screening tool that can pinpoint environmental hotspots in complex value chains (Hellweg and Canals 2014). A common way to reduce emissions is to focus on the elements of the product with the highest impact first. For different products, savings can be made in various ways throughout the life cycle stages and, as noted by the European Commission’s Integrated Product Policy Statement, it is important that all environmental impacts should be considered throughout the life cycle in an integrated way to ensure that negative impacts are not simply shifted from one part of the life cycle to another (European Commission 2003).
For manufacturing there are several ways to save embodied carbon of products, by using fewer materials, using alternative materials (higher recycled content), using ‘clean’ (renewable) electricity, or minimising waste (or re-using or recycling more) throughout the manufacturing process (WRAP 2016). For the construction of buildings (of which security measures may be considered a part), the use of recycled materials such as steel or aluminium, as a substitute for virgin materials, can confer savings up to 50% of the embodied energy (Chen et al. 2001). The way in which businesses monitor their environmental impact throughout manufacturing or distribution is also important, and the certification of environmental management systems has been shown to have a significantly positive effect on the innovation of more environmentally friendly products (Rehfeld et al. 2007). An example of how this approach has been applied within the security sector was recently demonstrated by a large door lock manufacturer: as a result of commissioning environmental product declarations (EPDs) for a range of it’s products, for a particular door lock, the number of materials used was reduced (material weight and thickness without compromising strength), aspects were re-designed and a custom-made nickel and chrome-plated material was replaced with stainless steel (Assa Abloy 2016). As well as modifying existing products, this approach by this particular manufacturer is also to be taken forward for new product designs, which will be instrumental for ensuring sustainability is considered throughout their product range.
Obstacles to environmental product innovation mainly consist of the economic aspects (such as the higher price tag often associated with products which consider their impacts more wholly) (Rehfeld et al. 2007). Through the changes in the example above, however, the environmental impact was reduced along with a 15% reduction of manufacturing costs (Assa Abloy 2016), demonstrating the potential economic benefits that also exist. It is likely that because of the higher costs, this is the reason our search found that few companies have undertaken environmental declarations of burglary prevention measures and further research within this area is needed. Completion of more environmental declarations would improve the knowledge base of where improvements can be made in regards to environmental impacts of existing measures. Moreover, advancements in technology also have the potential to reduce the carbon emissions associated with crime prevention measures, and indeed newer and smarter products, with lower carbon footprints, may already be available.
Other types of burglary prevention that are not physical products may also potentially offer low-carbon solutions to preventing burglary and other types of crime. Examples of this include advice and guidance from websites such as police.uk and thecrimepreventionwebsite.com. Common sense measures, such as not leaving valuable items on show, is often important in reducing opportunities to commit crime, as highlighted by ‘opportunity’ being one of the key drivers of crime within the Home Office’s Modern Crime Prevention Strategy (2016).
Other websites such as Immobilise.com—a national property register to help track items and repatriate them to the correct owner if they get stolen—also offer a presumed low-carbon service, as only the maintenance of the website and advertisements and travel associated with retrieving items would produce emissions. The reduction of emissions associated with the need to replace stolen items was highlighted as a large area of emissions (nearly 1.5 million tonnes CO2e) arising due to crime (Skudder et al. 2016). Property registers such as this, therefore, may help save emissions by reducing the need for items to be replaced.
In addition, many (but not all) police forces in the UK have Crime Prevention Design Advisors (CPDAs), also known as Architectural Liaison Officers (ALOs) or Designing Out Crime Officers (DOCOs), who offer free advice on new building projects as part of planning applications. Again, this may contribute to a low-carbon burglary prevention strategy. One example is promotion of the planting of vegetation such as thorny bushes along property boundaries as a natural deterrent as advised by Secured by Design (2014). Security advice such as this may even indeed be carbon positive as plants take up CO2 from the atmosphere.