The End of Night

The bright lights of Europe spilling into the night as seen from the Space Station.

Night is no longer as dark as it used to be. Street lamps, neon signs, ‘security' lights and the rest all contribute to an ever-present glow that has transformed the natural world and turned modern life into a wash of artificial light.

It is a theme the Lighthouse Keeper has looked at in several blog essays this autumn, partly inspired by one of this summer's best-selling books ‘The End of Night', written by US-based journalist Paul Bogard.

Light pollution around the world has expanded exponentially in recent decades and now it is reckoned that the vast majority people across Western Europe and the United States no longer experience a truly dark night.

Night's natural darkness is invaluable for our spiritual health and the health of the natural world and as a consequence every living creature, including ourselves, suffers from its loss.

Like the advancement of technology it is one of those things that changes subtly against the backdrop of busy lives – and almost without noticing we become accustomed to a new ‘normal'.
 

The Bortle scale, which classifies the darkness of skies from point of view of an astronomer, 
was originally published in Sky & Telescope magazine in 2001 and is an apt illustration for Bogard’s theme.

 
In his book, Bogard investigates the meaning of darkness and travels to some of the world's intensely lit cities - from Paris, the ‘city of light' to glittering Las Vegas and to still gas-lit streets of London's Westminster district, meeting an inimitable range of characters along the way.

Bogard contrasts the skies above our cities and urban populations to some of the most remote and darkest places on the globe, like the great national parks in America and the Island of Sark off the British coast.

He discusses how light is negatively affecting the natural world, how our well-being is significantly influenced by darkness or its lack, and how it's not a matter of using light at night or not, but rather when and where, how and how much.

Travelling the world looking for dark skies, Bogard considers our affinity for artificial light, the false sense of security it provides, and its implications.

He covers such broadly diverse issues as the health impacts of working the night-shift to the persecution of bats, and urges the reader to weigh the ramifications of light pollution and our failure to address them.  

The growth of light piollution across the United States, including
a projection for the year 2025.

 
"We think that because of television, the internet, or jet travel we see a lot of the planet," says Bogard.

"But the only chance we really have to retain our sense of the scale in the real universe is by looking at the night sky."

As we approach the winter solstice when the dark nights of the northern hemisphere reach their longest, what better time to delve into such a book?

Bogard's evocation of the night blends environmental and cultural history to make reading about light pollution a surprising pleasure.

By reclaiming the night we stand only to gain. Not least in decreased energy costs and redressing the balance of life but also in that other fast-disappearing phenomenon - wonder.

Bogard draws attention to the naturally dark night as a landscape in its own right - a separate, incredibly valuable environment that we overlook and destroy at our own peril.

‘The End of Night’ by Paul Bogard
is published by Fourth Estate and
is available at your local bookshop
or from Amazon.

Polar ice melt

Three major glaciers in West Antarctica (Pine Island, Thwaites and Smith) are melting into the Amundsen Sea faster than previously thought.

ESA’s Cryosat polar orbiting spacecraft possesses the capability to observe features in more detail than previous missions and has revealed that the region is now losing more than 150 cubic km of ice into the sea every year.

Cryosat was launched in 2010 with a radar specifically designed to measure the shape of ice surfaces - and its latest results indicate the loss appears to be accelerating

The data, presented at the recent American Geophysical Union (AGU) in San Francisco, show that the loss of ice equates to a 15 percent increase in West Antarctica's contribution to global sea level rise.

Prior to Cryosat, scientists concluded that ice losses from West Antarctica had pushed up global sea levels by some 0.28 mm a year between 2005 and 2010. The new Cryosat data starts from the end of that period.

Scientists say that ice at the Pine Island, Thwaites and Smith glacier ‘grounding lines’ - the places where the ice blocks split from the land and begin to float out over the ocean - is now thinning by between four and eight metres per year.


Three years of CryoSat measurements show that
the West Antarctic Ice Sheet is losing over
150 cubic kilometres of ice each year.

Launched in 2010, CryoSat carries a radar altimeter that can ‘see’ through clouds and in the dark, providing continuous measurements over areas like Antarctica that are prone to bad weather and long periods of darkness.

The radar can measure the surface height variation of ice in high resolution, allowing scientists to calculate its volume accurately.

Prof Andrew Shepherd of Leeds University, who led the West Antarctica study, said that part of the increase of ice loss could be due to faster thinning and part may also be down to CryoSat’s capacity to observe previously unseen terrain.

The mission has also provided three consecutive years of accurate Arctic sea ice thickness measurements, which show that ice covering Earth’s north polar region continues to thin.

Prof Shepherd added: "CryoSat continues to provide clear evidence of diminishing Arctic sea ice.

"From the satellite’s measurements we can see that some parts of the ice pack ice have thinned more rapidly than others, but there has been a decrease in the volume of winter and summer ice over the past three years.

"The volume of the sea ice at the end of last winter was less than 15 000 cubic km, which is lower than any other year going into summer and indicates less winter growth than usual."