For facilities, estate and sustainability teams, lighting sits right at the point where climate policy, energy costs and day-to-day operations meet. As governments look for practical ways to cut emissions quickly and affordably, how we light our buildings, streets, sports facilities, and public spaces is on the agenda, and the effects of these lighting solutions are of growing consideration.
There are four main reasons why lighting is attracting attention in climate discussion:
Light pollution, including obtrusive light, is artificial light that causes annoyance, discomfort, or harm by shining where it is not wanted or needed. While lighting is essential for safety and visibility, poorly designed lights become intrusive.
There are five main types of obtrusive light:
Clutter: An excessive group of bright, confusing lights
Light source intensity: This describes luminous power; how much light energy it emits per second. Depending on the distance and direction of the observer, its perceived intensity decreases as per the inverse square law (determining intensity for any source which spreads its influence without limits). If you have determined the amount of light per unit area reaching 1 metre, then it will be one-fourth as much at 2 metres.
There are several factors impacted by the presence of obtrusive light: environmental, human health, and energy costs. In the environment, wildlife behaviour can be artificially altered, impacting the local ecosystem of any area. Researchers at Cranfield University found that light pollution at night increases ecosystem respiration (when microbes, plants or animals release carbon dioxide through activity and growth) without any evidence of increased photosynthesis to counteract it. Excess light pollution impacts human sleep patterns, increasing the risk of insomnia and fatigue – negatively affecting mental health.
When light is wasted, so is energy, and so is money! It is estimated that approximately 30% of outdoor lighting is wasted, increasing carbon emissions beyond what is necessary.
Light pollution can feel like a symptom of the greater issue of urbanisation; it can be managed on small and large scales.
"Light pollution is one of humanity's most visible environmental changes, but its impacts are often hidden."
(Dr. Alice Johnston, Cranfield University)
The Institute of Lighting Professionals (ILP) have created guidance on what is considered acceptable based on the local environment.
| Zone | Surrounding | Lighting environment | Examples |
| E0 | Protected |
Dark (SQM 20.5+) |
Astronomical Observable dark skies, UNESCO starlight reserves, IDA dark sky places |
| E1 | Natural | Dark (SQM 20 to 20.5) | Relatively uninhabited rural areas, National Parks, Areas of Outstanding Natural Beauty, IDA buffer zones, ect. |
| E2 | Rural | Low district brightness (SQM ~15 to 20) | Sparsely inhabited rural areas, village or relatively dark outer suburban locations |
| E3 | Suburban | Medium district brightness | Well inhabited rural and urban settlements, small town centres of suburban locations |
| E4 | Urban | High district brightness | Town/city centres with high levels of night-times activity |
| Light technical parameter | Applications conditions | E0 | E1 | E2 | E3 | E4 |
| Illuminance in the vertical plane (Eᵥ) | Pre-curfew | n/a | 2lx | 5lx | 10lx | 25lx |
| Illuminance in the vertical plane (Eᵥ) | Post-curfew | n/a | <0.1lx* | 1lx | 2lx | 5lx |
*If the installation is for public (road) lighting then this may be up to 1lux. Limits apply to nearby dwellings / premises or potential dwellings / premises and specifically windows. The values are the summation of all lighting installations.
The current guidelines designate areas by their environment, which provides a maximum lux level allowed on a vertical plane. For example, E0 are protected, dark-skies zones and will not allow for any light on the vertical plane, whereas E4 are urban environments and allow for up to 25 lux on the vertical plane (pre-curfew). These protections ensure that local human and animal habitats are not disturbed.
We already have measures in place that prevent light pollution in all areas.
Despite years of progress, a significant proportion of lighting in the UK , especially in sport facilities, agriculture, municipal estates, and older commercial stock is still based on fluorescent tubes and compact fluorescents, high-pressure sodium and metal halide fittings, and ageing or poorly specified 'first generation' LEDs.
For many sites, upgrading to modern, high performance LED with appropriate controls can:
When policymakers look for large, near term carbon savings that are technically straightforward, lighting is an obvious goal to reach. That's why it has featured in the conversations leading up to and during COP30.
While the impact of these COP30 discussions has yet to be seen on the global stage, we can expect the standards for external lighting design to be practised with a more cautious approach with regard to light pollution:
Tighter efficiency standards: minimum performance requirements for new luminaires will continue to rise. Products that only just meet today's standards may fall short in a few years.
In this context, the difference between a well engineered LED project and the cheapest possible retrofit is more important than ever.
Swaps 'old for new' on a one-for-one basis without revisiting the design
With lighting increasingly linked to climate commitments, it's not just a purchasing decision – it's a strategic decision. A poor retrofit may tick one box today but fall short of expectations by the time COP31 arrives.
Well-lit streets, parks and outdoor leisure facilities encourage the use of bicycles, public walkways and public transportation and add safety to our outdoor spaces. In the climate agenda, public lighting appears as an ally of sustainable travel, from road safety to emissions reduction. Encouraging night-time leisure activities, physical activity and social interaction and promoting safer, healthier and more inclusive cities are all fundamental conditions for social sustainability.
Artificial lighting can impact biodiversity; sustainable projects consider reducing light pollution and using technologies that encourage the respect of the life cycle of flora and fauna. Sustainability must be integrated. New research has revealed, for the first time, the full extent of how Artificial Light At Night (ALAN) is increasing carbon released by plants and animals. Without an increase in the carbon they absorb. The result is reduced carbon storage in ecosystems, which has major implications for climate models and global carbon budgets. COP30 was a historic opportunity to align lighting policies with global climate neutrality goals.
To make sure your next project stands up to it, it is worth asking:
Does this design genuinely minimise energy usage while delivering the light my site needs?
Lighting may only be one piece of the net zero puzzle, but it is a piece you can control and one that can deliver substantial benefits quickly.
If you’d like to make sure your next lighting project is ready for the expectations and opportunities that COP30 will bring, speak to a Carbon8Lighting specialist. We’ll help you assess your current estate, design a high-performance, low-risk solution, and ensure your lighting supports your wider climate and operational goals for the long term.