Dark Skies or Safer Streets

Ecological Issues and Dark Skies

Hydrology published in August 2020 (and widely reported in the media) compared moth caterpillar numbers across both lit and unlit sites in the Thames valley over the last 3 years. Bats are a European protected species , which means they are fully and legally protected under law (This include, damage to or destroying resting / breeding places, obstruction of access to resting / sheltered spaces). ILP Guidance note 08/18: Bats and artificial lighting in the UK covers legal status, and also mitigations for lighting impacts on bats.

So what are the key topics we need to consider when providing lighting, especially for an ecologically sensitive area; Light pollution is a growing issue and it’s an

important topic to tackle. But why? Wasted energy - money wasted.

Impact on dark skies – lack of view of the stars. Nuisance and potential impact on both people and the wider ecosystem . French Law implemented in 2018 to tackle this was driven by non-lighting professionals – it was driven by location and it focused on the right type / quality of light for the location at the right time and controlled by the right system We’re adopting some of that good practice, and the ILP Guidance Note 01/21 – The Reduction of Obtrusive Light covers the same topics to minimise obtrusive light, sky glow, glare, light spill, nuisance light. An all Party Parliamentary Group was set up in the UK to focus on this as dark skies are really important to both people and our environment, and to also help promote good lighting. They make the point we don’t fully understand, the impact lighting (particularly LED) has on fauna & flora. It does recommend reduction in colour appearance <3000k.

Not all bats are the same but in essence the best lighting solution for bats is no lighting at all.

Now, we’ve all had involvement with schemes that have needed mitigations involved to meet requirements – eg missing columns from a scheme to prevent affecting known foraging routes. Using louvres on column mounted fittings to make sure that lighting is only on the task and there’s no spill away from the lit route, or even using low level lighting such as bollards (example using SLL & CIBSE Home Counties & NW webinar in July Bats: why dark skies matter – bollard solution ) Of course the best solution is no lighting , but if we are providing lighting, for example on a dedicated pedestrian / cycle route, isn’t it important to think about surround lighting to ensure good visibility / feeling of safety? And is this lighting approach really inclusive eg for those with sight impairment.

Impact of lighting (esp LED) on ecology in news: A report from the UK Centre for Ecology &

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