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Star Count 2021 results

6th April 2021

Dramatic reduction in light pollution during lockdown, nationwide Star Count reveals

Light pollution levels were much lower at the start of 2021 compared to previous year, finds CPRE, the countryside charity

Launched to mark International Dark Skies Week, CPRE’s annual Star Count shows a 10% drop in severe light pollution compared to 2020, and the largest percentage of truly dark skies since 2013

A nationwide Star Count conducted in February has revealed a significant drop in light pollution levels across the UK. The annual citizen science project asks people to count the number of stars they see in the Orion constellation.

Nearly 8,000 counts were submitted between 6 and 14 February 2021, with 51% of people noting ten or fewer stars, indicating severe light pollution. This compares to 61% during the same period last year. 30 or more stars indicates truly dark skies and were seen by 5% of participants - the highest figure since 2013.

Lockdown is the most likely reason for this change, with reduced human activity resulting in quieter than usual urban areas. Similar patterns have been found with air pollution, which has also dropped across the country.

The results 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.

Light pollution can negatively affect human health and wildlife by disturbing animals’ natural cycles and behaviours. Badly designed, wasteful light also contributes to climate change and obscures our connection to the Universe.

Therefore, CPRE and IDSA want to combat light pollution through strong local and national policies, while also protecting and enhancing existing dark skies. This involves putting the right light in the right places, such as LED lights that only illuminate where we walk, and turning off lights in places like office buildings when they’re unoccupied.

CPRE and IDSA hope this fall in people experiencing the most severe light pollution - an unintended but positive consequence of lockdown - continues long after coronavirus restrictions are lifted so more people can experience the wonder of a truly dark sky.

Crispin Truman, chief executive of CPRE, 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 appears to have fallen. It’s likely this is an unintended positive consequence of lockdown, as our nighttime habits have changed. Let’s hope we can hold onto some of this achievement as we ‘unlock’.

‘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:

‘IDA is delighted to learn of the turnout for this year’s Star Count, and congratulates CPRE for another successful event. The Star Count engaged thousands of people in the UK to get out and observe the night sky despite the limitations of lockdown, and the results are at turns both encouraging and concerning.’

‘We believe that solving the problem of light pollution begins with a realisation that the problem exists. For many people, participating in the Star Count may have been their first direct encounter an unpolluted night sky due to the loss due to the loss artificial light.

As realisation turns to action, we look forward to working with CPRE to bring attention and resources to turning the tide, and bringing natural night time darkness back to more of the UK.

Stars counted 



























The interactive map showing the results of CPRE’s Star Count 2021 is online here:



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