In case you haven’t heard the BBC are running another series of Stargazing Live starting on Monday 16 January for three nights. Each hour long programme will be presented by Professor Brian Cox and comedian Dara O’Briain, and will feature a wealth of information about what’s visible in the night sky.
This series will focus on light pollution, and the benefits of a dark sky.
On Wednesday 18 January, Dulverton in Somerset [in Exmoor Dark Sky Reserve] will attempt to become one of the first towns in the UK to have every single one of its lights turned off at the same time, as part of a Stargazing Live demonstration showcasing the beauty of a night sky free of the effects of light pollution.
There are 177 street lights in Dulverton making the night sky significantly brighter and making it much harder to see the stars. At roughly 8.15pm on Wednesday (or at the sound of a unique set of church bells), the Stargazing Live team want every single person in Dulverton to turn off every single light in the town, giving people in the area the unique chance to take in the wonders of the night sky free of the effects of light pollution.
To support this series, and encourage people to get out and look up, the BBC are sponsoring hundreds of events around the country, from planetarium shows to star parties, from lectures to observatory visits. You can find out what’s on near you on their events page.
To find out more about the shows visit their website, where you can view images, download their excellent star guide and activity pack, listen to some audio guides, watch “how to” videos, and take part in live web chats. You can also follow the series on Twitter using the hashtag #BBCstargazing.
Following on from my last blog post (“Do brighter street lights make you safer from crime?“), a Guardian “Comment is Free” editorial was published on 26 December 2011 under the title “In praise of leaving the lights on“. This article came after the widely reported words of Stella Creasy MP who called for a halt to street-light switch-offs until studies had been carried out into the effect on crime of reduced light at night.
In my previous post I cited several US studies that have shown that switching street lights off at night does not result in an increase in crime, and indeed in many cases brighter street lights resulted in an increase in crime.
I have subsequently read several British studies that also support this view, such as the 1991 Home Office Crime Prevention Unit Papers No. 28 and 29, entitled respectively “The Influence of Street Lighting on Crime and the Fear of Crime” (pdf) and “The Effect of Street Lighting on Crime and Fear: A Review” (pdf). These reports state that
no evidence could be found to support the hypothesis that improved street lighting reduces reported crime (Paper No. 28)
improvements to street lighting can help to reduce the public’s fear of crime, but that they make less of a difference to the prevailing level of crime than many people would expect (Paper No. 29)
However the Guardian editorial cites
a 2002 study by the Home Office [Home Office Research Study 251, HORS251] [which] found that “improved street lighting led to… an overall reduction in recorded crime of 20%” (pdf).
This seems to contradict the earlier Home Office studies. Might things have changed in the intervening 11 years? It appears not. The author of the 1991 Paper No. 29, Dr Malcolm Ramsay, a Senior Research Officer in the Crime Prevention Unit of the Home Office, wrote a 2004 paper in the British Journal of Criminology criticising the methods used in the HORS251 study.
The arguments in Dr Ramsay’s research paper are predominantly of a statistical nature. The introduction states that
the [HORS251] review at first sight appears to be an appropriate statistical synthesis of all studies on street lighting and crime across the world. However on close examination, the statistical claims and methods are unfounded.
According to Dr Ramsay, not only does the 2002 HORS251 report
use methods that ignore the large variation (known as “overdispersion”) in the data and implicitly assume that crimes are independent events, which is implausible in the extreme
but it also
is not comparing like with like, for the individual studies, in general. This is because brighter street lighting is applied to more crime ridden areas and the comparison areas are less crime-ridden and this will lead to an effect known as regression to the mean.
Further problems are apparent with HORS251. For example small studies are excluded for no good reason. Dr Ramsay’s paper concludes:
Crime reduction is frequently presented as a potent argument for increased lighting – here it has been shown that there is no scientific basis for this claim.
I for one welcome any new data on this issue, but in the light of the above criticisms of HORS251 it is unfortunate that the Guardian used it in a comment piece in praise of leaving the lights on.
Today, Labour Shadow Home Affairs minister Stella Creasy called for a halt to street-light switch off programmes in England and Wales, citing concerns that darker streets could result in an increase in crime and the fear of crime. She called for a halt until studies can be carried out on the potential risk.
Fortunately studies have been carried out that begin to address this issue.
The National Criminal Justice Reference Service (US) carries a 1979 report titled “Street Lighting Projects – National Evaluation Program Phase 1 Report” in the abstract for which it is stated that:
while there is no significant evidence that street lighting affects the level of crime, there is a strong indication that increased lighting decreases the fear of crime.
Following on from that study, other studies have since addressed the connection between lighting and crime.
For example, this report from 2000 (pdf), written by the Illinois Criminal Justice Information Authority, studied the effect of increased lighting levels in Chicago alleyways. The report begins:
In October of 1998, the Mayor’s Office in the City of Chicago and the Department of Streets and Sanitation began a multi-stage plan to reduce crime through improved street and alley lighting. The first part of the plan sought to upgrade and improve the city’s 175,000 streetlights, which illuminate the arterial and residential streets. The second part of the plan involves repairing and upgrading the lighting in and around viaducts and Chicago Transit Authority stations. The final part of the plan has been to boost lighting levels in alleys across the city as a tool for public safety and fighting crime. In the past, 90-watt lights illuminated most city alleys and the Department of Streets and Sanitation have increased alley lighting levels by installing new fixtures that can accommodate 250-watt bulbs. The intent of the City’s program was to increase feelings of safety and decrease crime in the alleys surrounding Chicago’s residential and arterial streets by increasing the wattage and number of alley lamps.
Once the lighting had been changed (made brighter) the report found that:
when the number of reported incidents for this one year analysis are examined, the data indicated that there were 428 total incidents reported in the pre-installation period and 519 total incidents in the post- installation period – an increase of 21 percent in reported offenses between the pre- and post-period test.
Each of the three crime categories experienced an increase in the number of reported incidents between the pre and post- installation period. Violent Index offenses increased 14 percent (119 to 136), property Index offenses increased 20 percent (30 to 36) and non-Index offenses increased 24 percent (279 to 347).
The city of Santa Rosa in California is carrying out and evaluating a street light reduction program between 2009 and 2012, the introduction to which states that:
Several academic studies have been published on the correlation between street lighting and crime. None of the studies make a direct correlation between increased street lighting and reduced crime. In fact some of the research indicates just the opposite, noting that the introduction of street lighting actually increased the occurrence of crime as perpetrators could monitor their actions without the use of flashlights or other lighting tools which could highlight the individuals’ presence.
The Santa Rosa 2009/10 crime statistics (pdf) show a decrease of a few % in both violent crime and property crime between 2009 and 2010 which matches the general trend across the USA.
Other studies will continue to shed light on this matter but at present it seems that, at best, increased light at night reduces fear of crime, but at worst may actually increase the crime rate. After all, criminals need light in order to commit crimes.
As reported on BBC online today, Highland Council have announced their plans to adopt street lighting trials in the Lochaber area (specifically at locations in Banavie, Strontian, Kinlochleven and Fort William) in order to reduce costs.
I have written this open letter to the Highland Council’s Lighting Manager Andrew Matheson:
I would like to congratulate you and Highland Council on your Lochaber street lighting trials. I appreciate that this was done primarily for economic reasons, but the benefits will be more than just financial. Excessive night lighting is responsible for:
- environmental degradation, through burning carbon unnecessarily
- impacts on wildlife
- impacts on human health
- nuisance to those that live nearby
- and spoiling our view of the night sky
I am a Glasgow-based astronomer, formerly manager of Glasgow Science Centre‘s planetarium, and formerly UK Co-ordinator for the International Year of Astronomy 2009, and I set up the UK’s first International Dark Sky Park in Galloway Forest Park in 2009, as well as the world’s first Dark Sky Island in Sark in the Channel Islands in 2011. I am working closely with a number of other parks and communities who are following suit, including Loch Lomond and the Trossachs National Park, and Orkney Island Council.
These parks and communities have recognised the value in reducing night lighting, not just in tackling the issues listed above, but also in establishing the areas as dark sky destinations, thereby bringing money in to the local economies in the often-quiet winter months, when dark nights lend themselves to stargazing.
If I can offer any assistance in the future please don’t hesitate to contact me. In the meantime I would very much like to come and monitor (using a light meter and a camera) the improvement in the night sky in the places which are adopting either a dimming of lights, a reduction in number of lights, or part night lighting, and would appreciate it if you could tell me which communities are adopting which lighting controls, and when these will start.