London's iconic night time skyline may soon look very different, as the city is set to trial rules requiring skyscrapers to dim or switch off lights overnight. 

A Bright Idea

The rules come with the increasing evidence of the devastating impact that light pollution has on both human and wildlife, in combination with growing pressure on the government to act on saving energy in aid of the current climate crisis.  

Under the new policy, a “lighting curfew” for all newly built developments would begin at 10pm for the City’s residential and heritage districts, 11pm for cultural and tourist areas, and midnight for commercial, retail and transport hubs. It would last until dawn and cover “any architectural lighting, or lighting without an essential function”.  Existing developments will be strongly encouraged to follow suit, but it will not be made mandatory in the current plans.  

How much energy does a Skyscraper use?

In many cities around the world, the glittering lights stay aglow long after the end of the work day, but maintaining an iconic view comes at a cost. 

One of London's most corporate and Skyscraper filled areas is Canary Wharf.  According to a 2020 analysis the energy used overnight by buildings in Canary Wharf  could power over 4,000 homes per year. For an area that is predominantly business lead, it can be assumed that the vast majority of energy used overnight, has been wasted.  A particularly eye opening figure amidst the current energy crisis. 

Just how bad is the light pollution in the Capital?

On a clear dark night, researchers say the human eye should be able to see thousands of stars. But less than 30% of people around the world are able to get a clear nightly view of the Milky Way, as in most built up areas, the view is blocked by artificial light. 

This artificial light has a devastating impact on biodiversity. 60% of wildlife in the UK depends on natural darkness to survive, as natural signals set migration, reproduction, and pollination rhythms.

There is also mounting evidence to suggest that light pollution is having negative impacts on human health as well.   With the light interrupting our circadian sleep rhythms, this can contribute to depression, heart and blood problems.