Light pollution levels were much lower at the start of 2021 when the UK was in lockdown, compared with a year before, a nationwide star count has found.
For the annual citizen science project, countryside charity CPRE asks people to count the number of stars they see in the Orion constellation on a clear night in February – and said this year’s results were “stellar”.
The count showed a 10 percentage point drop in people experiencing severe light pollution compared with February 2020, a change the charity suggests is likely due to this year’s lockdown, which reduced activity and led to quieter than normal urban areas.
Nearly 8,000 results were submitted between February 6-14, with 51% of people noting 10 or fewer stars, indicating severe light pollution in their area, compared with 61% of people in February 2020.
The results also show that 5% of people enjoyed truly dark skies – with 30 or more stars visible within the Orion constellation – which is the highest figure since 2013.
The findings of the survey have been launched to mark International Dark Skies Week, run by the International Dark-Sky Association (IDSA), which raises awareness on the impacts of light pollution.
Campaigners warn light pollution can harm human health and wildlife by interrupting natural cycles and behaviours, while wasteful lighting also contributes to climate change.
CPRE and IDSA want to combat light pollution through national and local policies, such as using LED lighting that only illuminates where people are walking, and turning off lights in places including unoccupied offices.
Crispin Truman, chief executive of CPRE, the countryside charity, said: “It’s been an absolutely stellar year for star count.
“We had three times as many people taking part compared to previous years and I’m delighted to see severe light pollution in the UK appears to have fallen.
“It’s likely this is an unintended positive consequence of lockdown, as our night-time habits have changed. Let’s hope we can hold on to some of this achievement as we come out of lockdown.”
He added: “Looking up at a starry night sky is a magical sight and one that we believe everyone should be able to experience, wherever they live.
“And the great thing is, light pollution is one of the easiest kinds of pollution to reverse – by ensuring well-designed lighting is used only where and when needed, and that there is strong national and local government policy.”
Ruskin Hartley, executive director of the International Dark-Sky Association, said: “We believe that solving the problem of light pollution begins with knowing the problem exists.
“For many people, participating in Star Count during lockdown may have, for the first time in a long while, have been their first encounter with a dark night sky.”
He said: “As realisation turns to action, we look forward to working with CPRE to bring attention and resources to tackling night blight, bringing dark skies to more of the UK.”