Sustainability, climate change, cleantech and energy : a selection of the latest headlines and best researches.

Posts Tagged Dark sky

Animation : Borrowed light, by Olivia Huynh

Borrowed light by Olivia HuynhThe previous nights were the occasion to see the Perseid meteor shower. It was also the Nuits des Etoiles in France, where hundreds of events are organized to allow people to watch stars and (re)discover the sky and stars above our heads.

As you perhaps know, I am quite an astronomy fan and I believe it is very sad that the skies aren’t dark anymore. So when Grist published an article about a cute animation on that very topic I knew I had to share it with you.

Borrowed light by Olivia Huynh made me wish for a darker sky and to be able again to enjoy the marvels of the stars, galaxies and nebulae. Read more

Starry, Starry, Starry Night

Rio de Janeiro without any lightsYou may perhaps remember the not so distant time when I was posting astrophotography pictures on this very website. I have also wrote a few times on how we are lighting up our cities too much.

Now a fellow Frenchman, Thierry Cohen, created a series of pictures of what the night could look like if cities like Paris, New York, Shanghai or Sao Paulo were to turn of all their lights. The result is quite stunning.

Not that I am advocating turning off ALL lights at night in our cities, I am just thinking that we should see more stars at night. Read more

France unveils measures to decrease energy use

Eiffel tower without its lightsHere is another post I wrote for Cleantechies, this time on energy conservation :
” Even after the election of François Hollande as President of France, an energy conservation measure of the previous government will be implemented.”

” The Sarkozy government wanted to require shops and offices to turn off their unnecessary lights at nights. This will be effective as of July 1, 2013. All nonresidential buildings will be required to shut off their lights (…) by 1 a.m.”

While this measure is tiny compared to what has to be done on energy conservation, let’s hope the current government will go forward in this direction. As usual, please enjoy and share !

Urban lights increase air pollution

Too many lights in our cities at night is really bad for our economy as we waste electricity and thus money. It is also a bad idea for nocturnal animals, plants and amateur astronomers who need to go further and further to have a darker sky.

Now, to a new American study, too many lights is also a bad thing for air quality. As the BBC notes : ” Their research indicates that the glare thrown up into the sky interferes with chemical reactions.”

I am not sure this is the definite argument to push forward slashing the amount of lights but this is still something to point to if the ordinary fails to convince…

For many, the sky isn’t dark anymore

I already wrote a few articles on dark skies and light pollution. It seems the phenomenon is even worse as one can see with the image on left (courtesy of Stellarium, a great astronomy freeware)

This also has an important impact on greenhouse gases emissions. In Australia alone, public lightning is responsible for 1.15 million tonnes of CO2 emissions each year. I guess it’s high time to install more efficient lights in our streets.

Barcelona have a great idea that should be replicated all around the world. This way, streets would be lit only when needed and with energy efficient lights. This would reduce consumption by 30 percent.

Barcelona’s amazing smart lightning idea

The city of Barcelona and Spanish utility Endesa have been installing smart LED lightning systems that automatically switch themselves off when no one is around. This enables the city to cut by 30 percent its electricity consumption.

I really would like this idea to spread across Europe and even the entire world. Indeed, how many plants are used only to light streets unnecessarily? This would drastically cut costs and would go far beyond the Earth Hour

Last but not least, this would also improve the night sky quality drastically. As we have seen previoulsy, darker skies would benefit Nature and astronomers alike. Read more

Pictures of Earth Hour: how we waste energy

acropoleEarth Hour was a tremendous success as many people participated. Cities turned down the lights of  their monuments and the pictures of the event are amazing and totally illustrate how much energy and money we could save.

The Boston Globe proposed a series of 17  great pictures illustrating the phenomenon. Instead of turning down all those lights one hour per year, couldn’t we do this every night after 10 pm or midnight ?

This would make two to three thousand hours and subsequent savings in money and greenhouse gases. Another plus would be darker skies. What do you think ?

Assessing and ending light pollution

nightearth_bigLight pollution is a major problem for astronomers in most if not all countries (see map) . But for the International Year of Astronomy this may change with the following initiative.

Globe at Night allows astronomers to easily assess the phenomenon with a series of charts. By watching the Orion Constellation, it is simple to know if your local sky is polluted or not.

Significant changes have been reached in the past few years in local areas but we now need a global initiative to decrease the amounts of lights of our cities and suburbia. Read more

Let there be more light ?

europeatnight.jpgThis week-end was held in Slovenia the seventh European Symposium for the protection of the night sky.

This is the occasion to have a look at the lightning of our cities at night. As more lights mean more greenhouse gases emissions, we will have to reduce the amount of lightning to fight climate change.

The image used for this article is Europe and North Africa at night, according to the Nasa. With this, I believe one can really understand quickly the problem.

Read more


A French Management professional - now for hire - Edouard Stenger has been selecting since 2007 the latest headlines and best researches on sustainable development, climate change, environmental issues, cleantech and the world energy sector.


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