International Dark Sky Week 2023

Whilst in the UK we’re officially in springtime, and the days are becoming brighter, around the world communities are preparing for International Dark Sky Week 2023 from 15-22 April.

Northumberland is famous for it’s dark skies, a shared global, natural and cultural heritage which we can all experience.

International Dark Sky week highlights dark sky conservation issues around excessive and inappropriate use of artificial light at night (ALAN) and calls for us all to do something positive to reduce the effects of light pollution.

Wherever you live, you can help to protect dark skies.

Types of light pollution

There are three types of light pollution to be aware of:

  • SKY GLOW is the apparent brightening of the night sky that appears above our towns and cities and is caused by poorly-directed light sent upwards and scattered by aerosols and particles in the air, as well as from reflected light off hard surfaces.
  • GLARE is the uncomfortable brightness of a light source when viewed against a contrasting darker background e.g. an LED floodlight on the side of a house that is angled outwards.
  • LIGHT TRESPASS describes light that spills onto ground beyond the property, including natural habitats and areas of wildlife interest.

Light pollution can:

  • disrupt wildlife at night – nocturnal animals like bats, insects and amphibians sleep during the day and are active at night. Birds migrate by moonlight and starlight. Light pollution from excessive artificial light at night alters their night-time environment by turning night into day.
  • impact on our health & wellbeing – humans are animals too, and we respond to the rhythms of the natural light-dark cycle of day and night. The spread of artificial lighting means that many of us no longer experience truly dark nights, and some research suggests that artificial light at night can negatively affect upon human health, increasing risks for sleeping disorders, depression, diabetes and more.
  • waste energy, create carbon emissions and cost money – artificial lighting that emits too much light or shines when and where it’s not needed (upwards) is very wasteful, with significant economic and environmental consequences. It is estimated that in the UK, £1 billion of energy is wasted lighting up the night sky!
  • block our view of the universe – Light pollution caused by sky glow emitted from our town, cities and highways effectively cast a veil across our skies. In a light-polluted ci urban environment you may only see 56 stars on a clear night, whereas by moving well away from sources of artificial light at night, such as in the National Park, you will see more than 2,000 stars, including the Milky Way!

Help reduce light pollution and care for our wildlife

Here are 3 things we can all do to help reduce light pollution and care for our wildlife:

Do a simple home audit of your outside lighting by:

Assessing each outdoor light on your property using the IDA’s Five Principles for Responsible Outdoor Lighting (see below

Improving or replacing any of your lighting fixtures that you don’t need.

Become a citizen scientist by measuring and submitting your night sky brightness observations. It’s easy to get involved and all you’ll need is a smartphone – visit:

Support campaigns to reduce light pollution, see:

    1. International Dark-Sky Association
    2. The Commission for Dark Skies
    3. CPRE
    4. Buglife