Study context

In December 2020, Natural Resources Wales (NRW) commissioned LUC to develop a new nationally consistent terrestrial Tranquillity & Place – Dark Skies map that identifies the strategic and local resource in remote, rural, peri-urban and urban areas for use as an evidence base to inform policy intent, practice and provision for wellbeing benefits.

What is the aim of this study

This study was commissioned out of recognition of the importance of night skies free of light pollution, both for humans and for wildlife. Light pollution can impact our perception or experience of nature, landscapes and greenspaces and the cultural benefits they provide to us.

Future work will consider the degree to which places, greenspaces and ecosystems deliver relative tranquillity and opportunities for state of quiet, calm, peace and well-being including relative soundscapes. This report focuses on the degree to which places and ecosystems deliver relatively dark skies. Ultimately the collective work strands will be used to build up a new Tranquillity Map for Wales.

In order to achieve this, this study involved the creation of the following;

• A Wales-wide dataset of dark skies and light pollution.
• A set of maps displaying the dark skies data against various geography levels.
• Zonal statistics for each of those geographies.
• A poster of the dark skies data.
• An interactive web map of the dark skies data.
• A report of the findings.

What does this report cover

This report provides details of the method used to create the data, and a record of the outputs of the study. It includes analysis of the findings, presented in a visual way where possible, as well as comparisons against local streetlight schemes and Sky Quality Meter data.

Overview of key findings

The night sky, the patterns of the stars and the shapes of the constellations, have been incredibly important to our ancestors throughout human history. But our relationship with the stars has changed; our ancestors saw the night sky in a way that is impossible for most of us today; just a handful of the brightest stars are visible in urban areas due to light pollution, the effects of which can be seen in all but the most isolated places.

There are very few areas of the world, especially in countries with large urban populations, that are completely free of light pollution, so it’s vitally important to protect and preserve those few areas that are.

The key findings of this study were:

• More than 2/3rds of Wales falls into the darkest category defined within the data.
• Mid Wales is the darkest region, with more than 90% of it falling within the darkest category.
• On average, 95% of the three National Parks and five AONBs in Wales fall within the darkest two categories.
• Whilst potentially influenced by the sensitivity of satellite sensors in the LED wavelengths, the amount of light emitted in cities appears to be decreasing, but the areas around cities seem to be getting brighter.