Qu: What are ‘successful’ ways to campaign for residents to reduce or turn off lighting like security lights? My neighbour who lives behind me called me a moaning minnie when I spoke to her about it from a wildlife point of view. She has about 6 lights. How can we help people to want to reduce or remove them? 

Jess – at the ILP (who are a charity not a trade body) we worked on advice, but it does need updating. It has a good diagram about how to angle the lights. Look at adapting lights rather than removing. When people realise the wider effects their lights are having, then most are likely to want do something to solve the problem. 

Lee – in the main in retailers, the stronger wattage lights seem to be better value which people generally go for. So in certain circumstances, existing lights could be dimmed and reduce the output. 

Bob – it is difficult to convince them that lighting will always deter criminals, the brighter the light, the less a deterrent it will be. Most burglars think that bright light will be helpful to them. The power of a light has no correlation to how well it will deter criminals. Quite the opposite. 

Ian – There are many contractors installing lighting that have no clue. Education could also be applied to housing developers. And the design of the lights needs looking at.

I think it’s important to tackle light pollution in 2 ways. First during new developments and 2nd existing lighting.  How do we get local planning authorities to consider lighting more when determining new developments? 

Bob – the APPG (All Parliamentary Party) for Dark Skies is looking at light pollution, and this is one of the things that they are trying to push. They have suggested 10 policies to sort out light pollution one of them is to incorporate light pollution into the planning process. At the moment, the only consideration is how a light looks on a building in the daylight, not how it performs or affects its surroundings at night:

https://appgdarkskies.co.uk/policy-plan 

Lee – I have been involved with some situations involving the Clean Neighbourhoods and Environment Act 2005. So there is law, planning policy does include it in NPPF (National Planning Policy Framework) and NPPG (National Planning Practice Guidance).  Have seen a rapid uptake in assessments and use of the guidance on obtrusive lighting. 

Bob – cases raised through this Act are very rarely taken up by Councils. Some have requested doctors’ letters to prove and only sending officers around during daylight hours. 

Qu: What options are available for hotels, cafes and pubs to reduce the impact of their lighting but to remain health and safety compliant to visitors and guests?

Jess – ask a lighting professional to design the lighting for you! They will design something beautiful and inviting and you can do it a lot more cost effectively by getting somebody who knows what they are doing and does it in a way that protects the environment. 

Lee – we only require health and safety when there’s somebody there, otherwise the unit can dim down. So what I’ve been doing is integrating, when it is a particularly sensitive area of a site, I will say that we will only have these units on if somebody is in the area, otherwise they will run at 10%. You can do this for individual light fittings so it has their own sensor. Technology is now catching up. You’ve probably all heard of LED, it is not a traditional light bulb that you can’t dim, you can do a heck of a lot with it.

Qu: Staying with the first question, why can we not build into building regulations rules that must be obeyed, type of luminaire and how to install? Most cheap luminaires have no optics to cope with downward commissioning for example. 

Bob – for more than 30 years, we at the CfDS (Commission for Dark Skies), CPRE and Bug Life, have been talking to the building, planning, DEFRA and local govt, Do the ‘guidelines’ work? No, we need legislation.

If France, Mexico and Slovenia can do this why can’t we. 

Lee - I agree, we need law. You cannot rely on human nature. We have building regs, part of which is control of external lighting, but it’s about achieving a credit for a development. The local authorities do not have the ability to judge something. Very often they are using out dated guidance. Monitoring should be invoked. So in 6 months time after installation the lighting should be reviewed and remedial measures implemented if necessary.

Qu: In ILP (Institute for Lighting Professionals) GN01/20 there is a table (Table 4) that non-professional lighting specialists find difficult to understand. Is there any simple text that can assist in understanding and applying what is in the table? 

Lee - The glare intensity? Yes, it’s tricky! Now we are looking at specific light fittings and their intensity relative to the environmental zone that it is being viewed from and against. It tackles the fact that you can have the intensity of a light fitting which might be fine, but the background might be very dark. So that intensity contrast ratio differs so much that the glare increases to the viewer. So they say that you need to change the environmental zone, to notch it up one, so that you are not delivering too much of a contrast ratio. Which is the key problem of glare, the contrast ratio. You don’t get glare from a lit white wall because there’s light everywhere. You get glare from a little LED pinpoint because that brightness is so much greater than the surrounding brightness. Yes, the table is very technical, it follows the CIE 150 which is the European guidance and ILP have adopted it in their reports. Speak to a lighting professional. 

Bob – look at the website of the CPRE, Bug Life and Commissions for Dark Skies (CfDS). You’ll find a 40 page handbook all about biodiversity, climate change, all this non stars stuff. It’s in their interest to make it simple because the people who look at the websites tend not to be lighting professionals:

https://britastro.org/dark-skies/pdfs/CfDS_booklet_Rev07.pdf 

Jess – For anyone who doesn’t know GN01 stands for ILP’s Guidance Note Number 1. So it is the very first of all the guidance notes that we give out. It’s free on our website and it’s about what the engineers call obtrusive light and what most of the rest of us call light pollution:

https://theilp.org.uk/publication/guidance-note-1-for-the-reduction-of-obtrusive-light-2020/

There is a webinar that goes along with it that you can watch for free and we also have an educational course which you can book on and go on.

Qu: For wildlife what is the best lighting spectrum, lights, we should be asking for? 

Lee – it depends on the species. There is no published guidance on light levels, however there is guidance on the wavelength of light.  A lot of species like the ultraviolet spectrum. It’s recognised by bat conservationist trust guidance that the colour temperature of the light source should be sub 2,700 degrees kelvin, which is considered as being a warm white light source: https://cdn.bats.org.uk/pdf/Resources/ilp-guidance-note-8-bats-and-artificial-lighting-compressed.pdf?mtime=20181113114229

Even better, and I’ve been working with Bug Life on this, is amber light source, a single wave length of light. There’s no distraction from a single wave length of light up in the amber ores. Amber LED is widely available. It’s got to be a pure wave length. Even though it gives you weak colour rendering e.g. a red car will appear brown. But is it always necessary to determine the colours at night? Essentially when we are only in black and white vision anyway as a human. Moving towards the warmer spectrum, less blue content, is the way to go for wildlife. 

Bob – I agree entirely with Lee. It’s quite tragic that Councils are choosing blue rich lighting. The people who invented the bright blue lighting got the noble prize, I do hope they’ve thought about the consequences of what they’ve invented. Another point of course is the angle of the light that makes a lot of difference to creatures like bats that operate in the air. If you’re going to keep bats from staying in their roosts for a long time because they still think it’s daytime. There was a study in Slovenia of bats not leaving their roost at all because of all night lighting and just dying of starvation. Keep the blue out of it and point them downwards, nobody needs to shine a light into the sky. Warm white or amber is brilliant. People don’t realise that you can get non-white LEDs.

Qu: Has anyone found a rental company for construction site generator sets with pole lighting that provides sets suitable for use in AONBs? 

Lee – this is a problem as they just use the brightest lights because they are seen as ‘temporary’ but can be left in situ for months!

Qu: Is the colour choice (i.e. cool vs warm) a relevant factor in pollution terms? 

Lee – absolutely it does. There’s something really techy called the Rayleigh effect, this is why the sky is blue. The blue wavelength enters the atmosphere and scatters. If you have a light source with blue light content in it which makes it cool, what do you think that blue light does when it leaves the light fitting? It scatters and is going up, it looks glarier and is bad for the wildlife. There is no real benefit to having blue light within our white light. Cool versus warm, warm is a winner every time. 

Bob – absolutely agree with Lee. In addition, the American Medical Association have declared light pollution, especially bluish light, as a health hazard to human beings. A lot of people in the lighting profession have asked for more evidence, you need to expose yourself to it for a very long time. How about the precautionary principle? If it might be damaging, try not to do it, just in case. 

Ian – When LEDs were first invented there was probably more widespread use of the cooler temperatures, even as high as 6500, Kelvin, but the standard accounted for that with the SP ratio. So, if you’re going to use a cooler temperature LED you actually use less power and light to lower levels, because of exactly what the saying is, the eye perceives it to be brighter. I’m not sure if I wholly agree with comments that every bluer rich light is glarier, because if it is designed correctly it shouldn’t be because it should be at a lower power. It’s about good design and appropriate design.

Qu: The promenade at Grange-over-Sands (Morecambe Bay) is due to be redeveloped and excessive lighting added. What would you suggest?
How can we lobby the council to consider light pollution? 

Jack - FLD and others are on the case and will make sure that if lighting does go ahead that it is appropriately designed and wildlife friendly.

Qu: As a planning officer in an Area Of Outstanding Beauty what do you recommend I focus on when commenting on planning applications, in order to reduce light pollution? 

Lee – does the AONB have its own specific policy on lighting, if not, it should have, the policy ILP GN01 which classifies an AONB as an Environmental zone E1.  They should be insisting on a Lighting Impact Assessment  and lighting strategy and what the colours temperature, the intensity of the light fitting, all feed in to the ILP guidance. If they have their own policy, that will feed into the guidance. 

Ian – Need to ask about lighting calculations on a vertical plane as well as the horizontal plane. This is often overlooked. 

Lee – agree with Ian bats fly in the vertical plane not the horizontal one! The values are always different, sometimes higher. 

Qu: Is it possible that the ILP Guidance GN01 will have more weight than just 'guidance'? 

Jack – the NPPF is being reviewed at the moment, and tackling light pollution is going to feature higher in the planning process we hope.

Qu: Are most LEDs manufactured with optics bonded to them as a single unit these days? 

Ian – yes they are. Early models possibly not. You get what you pay for. Some criticism and issues with LEDs relate to early ones. The development of LEDs is moving at a very fast pace. Have found it challenging previously, but new LEDs are very different to previous models. 

Jack – I’m talking to major lighting manufacturers and they are very receptive to light pollution concerns. 

Lee - A 2 year old LED is out of date. I have an I-Phone 8 and my daughter thinks its incredible old! You can control your lighting using Smart phone technology now. 

Jess – there are some super responsible manufacturers out there.

Qu: What would you recommend to project managers who are building new housing developments with regard to outdoor lighting fixtures? What could I signpost them to in terms of good lighting policy for new housing? Is there any literature to give them? 

ILP and CfDS guidance (referenced above). 

Ian – two different types of lighting involved – public lighting, local authority – and then exterior lighting, domestic. Education directed to housing developers. 

Bob – the Commission of Dark Skies contains a multitude of experts and has a handbook on their website with a free download, advice to developers, lighting principles. 

Qu: Any advice on minimising light pollution from windows and Velux. Some new developments have large gable window. Where is there good guidance on this please? 

Bob - See our free download: https://britastro.org/dark-skies/pdfs/CfDS_booklet_Rev07.pdf

Lee - better quality fittings with optical control would reduce light spill yet still illuminate the required area. The energy saving from this more efficient solution would help pay for the initial extra outlay for the lantern. I suggest this should be the educational message to residents. 

Ian – valid point – it’s about education, correct application of the products, and you get what you pay for. If you’re not prepared to pay for the quality product, then you won’t manage it effectively.

Qu: Policy and improved technology are both helpful but is there a bigger issue here - have we all got so used to a lot of artificial light in our lives that we simply do not understand the problems it causes to our health and the environment? 

Bob – it’s true. Everyone has grown up with unregulated lighting. People think it is normal. 

Ian – we predominantly light up people. The primary complaint is that LEDs are not bright enough. The expectation of people is that they want that lighting. We shouldn’t lose sight of why a lot of lighting is there for people. 

Jack – yes, it’s all about a balance. Social values around perceptions of safety just as important as considering environmental impacts. 

Lee – we have a 24/7 lifestyle, lighting serves a big part of that, otherwise our western world would come to a standstill. 

Qu: When a neighbour has 3 lights on their house on all night or at least until midnight what main arguments would you use in discussing it with them with a view to get them to turn them off? 

Bob – just approach them. A large number of people don’t realise that it’s a problem until you bring it to their attention. 

Qu: Does anyone know what Colour Temp moonlight is please? 

Lee – I don’t believe any of what is written! It varies dependant on the angle of the sun and the reflection hitting the moon. 

Bob – there is no such thing as moonlight – it is faintly reflected sunlight. It is difficult to assess its’ effect. Full moon is about half a lux. 

Ian – lux = unit of illumination. Potentially more conflicting information out there as this subject evolves, but in years gone by moonlight has been given a colour temp of 4,000 Kelvins. But we are all becoming more educated. 

Qu: Great Discussions on lighting and apparent lack of education as being one of the causes. What do the panellists think of encouraging artificial lighting into the National Curriculum within the sciences more formally in a practical way so that future generations have this in their memories for life?

Bob – the National Curriculum Science modules do mention different kinds of light and wavelengths, natural lighting and light pollution. 

Jess – one of my colleagues in the ILP are doing some TikTok videos to appeal to younger people. 

Qu: There is some research from the USA that suggests that the uniformity of lighting is more important than 'brightness'. Comment? 

Lee – absolutely! Uniformity is about avoiding dark spots, which would cause a health hazard and anti-social behaviour. 

Ian – we are looking at 40% uniformity, and if it is not at least 40% people’s perception changes and becomes a one of ‘that lighting isn’t very good’. 

Bob – Uniformity is more a question of design than intensity of light.

Ian – that’s a very valid point when you made your decision the energy gap was very real around 20%  Local Authorities don’t have that gap to worry about any more so why is 4,000 Kelvin still being specified by some? 

Ian - Different procurement process? Lack of real knowledge?  Ours was a policy decision.

Qu: In the context of the effect of contrast in lighting in causing glare, how does reducing street lighting affect glare from car headlights? 

Lee – has investigated it and it is usually the bog standard flood light, as cheap as possible put on these things because it’s “temporary”. It’s a temporary solution. It shouldn’t be as bad as they are but I haven’t found one that I could say that’s a good solution. 

Bob – when motorways have night time closures have a big sign that says “40 miles an hour to protect workforce,”, and as you approach the workforce there are massively temporary glaring lights and I think they should have a sign saying “beware, glaring lights that endanger workforce.” Why have a speed limit when you dazzle the drivers? 

Ian – Anybody who’s driven on the M6 through Cumbria may wonder why we have two lighting installations; one at Shap and one at Tebay Gorge. They’re there because those are cross over points for major motorway works. When working for a private company I did the design for them about twenty years ago and they are all flat glass lanterns. They were put in as a semi-permanent installation. Some of the solutions are not new, they are decades old in some instances.

Qu: What are the two priorities for tackling light pollution?

Bob – “education, education, education,” make sure that everybody knows. Everybody now knows the term ‘light pollution’, but I think that people who live in intrinsically dark areas really ought to be bombarded with as much information as possible about getting their light right. 

Jess – remember that nobody wants to do this deliberately. If you’ve got a problem with your neighbours light they haven’t done it to annoy you, they’ve done it for a reason. Find out what the reason is and go from there. The second priority is to go and ask an expert to design the lighting well because it makes such a difference. 

Lee – I would tax light polluters and I guarantee that would stop light pollution. I would say that light pollution is equivalent or if not more than issues for the environment. The amount of light pollution that we have and what’s going on in the world with development now and it will continue to happen. Light pollution doesn’t have enough exposure on the public forum. We need to raise that bar and make people aware of the issues. 

Ian – The Georgians did tax once and they put it in the window tax, that’s why you see all these old buildings with the windows bricked up! Education has been the thing that has gone right through and I think managing expectations is a big part of it. It’s what people expect to get and what they maybe will get in the future. Always champion good practice at all times. It’s important to make sure that there is an element of balance in it. I think that both sides of the argument can resort to a bit of rhetoric at times and use evocative terms and phrases. Personally, I think that it is probably unhelpful in a meaningful and educational debate. We need to find out what the real facts are.

Qu: Security lights, external bright lights, angled badly and glaring everywhere, what can we do to tackle those?

Ian - No straight forward solution, more good practice, 9 out of 10 people buy lights and angle outwards and upwards as it gives them more coverage, therefore, better value for money. We need to make consumers understand the good practice. 

Bob – local media is a good source for public information. It’s nearly always a case of badly angled lights. But some, especially from China that aren’t able to be re-angled. We need standards to guide the manufacturers of luminaires and fittings that are dark skies compliant.