These
days we often hear about pollution in its various forms but another form of
pollution – light pollution - is a
problem which many people are not aware of. Light pollution is gaining increasing
attention from astronomers, environmentalists and people who wish to reduce
energy consumption.
What is
light pollution? The International Dark
Sky Association defines it as the inappropriate
or excessive use of artificial light. There are four components of light
pollution - glare, skyglow, light trespass and clutter.
Glare is
excessive brightness that causes visual discomfort and skyglow is the light
halo over inhabited areas. Light
trespass occurs where light falls where it is not intended or needed and
clutter happens where groupings of light sources produce a bright, confusing
effect.
The Dark
Sky Association points out that much outdoor lighting used at night is
inefficient, unnecessarily bright, poorly targeted and not properly shielded
which means it is spilling into the sky rather than doing the job it was
intended for. This of course means that
much of the electricity used to create it is being wasted.
According
to a 2016 study, 80% of the world’s population lives under skyglow. Major population centres like the United
States and Europe are heavily impacted.
There 99% of people are unable to experience natural night.
While
skyglow away from our major cities is not as bad as in Europe, the US and Asia,
we are still affected by it. Even in comparatively small population centres
like Grafton we do not see the night sky in all its glory. If you visit areas
in western NSW away from towns and look at the night sky on a cloudless night,
you are likely to be amazed at the clarity of the heavens and immense number of
stars.
Light
pollution is not a concern merely because of aesthetics and the need to
conserve energy. It has impacts on human
health and disrupts ecosystems and wildlife – effects which will be discussed
in a future “Voices of the Earth” column.
- Leonie Blain
This article was originally published in the VOICES FOR THE EARTH column in The Daily Examiner on June 5, 2017.
