Blog 9- Pollution

Hong Kong's light pollution 'worst in the world'

Light pollution occurs when artificial light intrudes on the nighttime setting. The modern mega-city of Hong Kong, with its dense population, is the world’s worst city for light pollution, says a study from Hong Kong University. The pollution is created from the blaring neon flood lights and billboards of advertising around Hong Kong. The result is that the lights block the night-time starry sky. The worst lights seem to be those that are shot straight into the sky for a dramatic effect. The government has no regulations for this lighting like in other parts of the world because the lights are considered necessary for public safety. The ecological impact that results from the wasteful light pollution has been ecologically damaging to migratory birds and nocturnal animals that depend on light to regulate their lives. The lights of Hong Kong, measure 1000 times international norms. The glare is made worse due to the high levels of air pollution in Hong Kong. The pollution has tiny particles and these particles reflect the glaring light back into our eyes. Add 200 cloudy nights, and there are few places around Hong Kong where you can see the stars at night.

Hong Kong is not the only megacity on earth that has major light pollution problems. Light pollution is a global phenomenon. Look at New York, London, Moscow, Madrid and all the mega-cities in the world. You can see the different images of light pollution just by looking at a Google earth map. When you compare the night sky of the 1950’s to those of now, it is striking how different the sky of 60 years ago looks from today’s glaring sky of light pollution. All of the mega-cities have increased their use of lighting ten-fold. The increased lighting globally has blocked many city skies and this means it has blocked the beauty of the cosmos. This waste of energy contributes to our global warming and produces high energy bills. The light pollution has an adverse effect on the health of animals, plants, humans and the environment. In humans, light pollution can interfere with natural circadian rhythms by preventing the production of melatonin, the chemical that regulates sleep patterns. Low melatonin levels have been linked to increased cancer risks. Night lights disorient hatching sea turtles, migrating birds and nocturnal animals. Lights attract insects, which may in turn interfere with pollination of nocturnal flowers. Light pollution negatively effects our entire global environment.

The night sky in the country looks remarkably different than the sky view near a city. More stars are visible and brighter, and in some remote areas, the Milky Way galaxy extends across the sky from east to west. Sky glow, however is the orange light that we get at night above a town or city that even interferes with how we see the sky at night. Sky glow occurs when artificial light which shines upwards, reflects off clouds and atmospheric particles such as dust and water, causing a ‘scattering’ effect. Although light in the right place, makes urban areas safer and more pleasant to be after dark, if not designed properly, it can also have negative effects. In the design of our global mega-cities, light pollution will need to be regulated and measured to ensure that our global environment is protected from light pollution’s adverse effects.

http://www.cnn.com/2013/03/21/world/asia/hong-kong-light-pollution

By Peter Shadbolt, CNN

updated 12:55 PM EDT, Thu March 21, 2013