Light and sound pollution and their effects on the natural world

Cambridge-educated science journalist Ed Yong wrote the cover story in the current edition of The Atlantic, and it’s all about the disastrous effects that light and sound pollution are having on the natural world.

Just one example from the article:

Every year on September 11, the sky above New York City is pierced by two columns of intense blue light. This annual art installation, known as Tribute in Light, commemorates the terrorist attacks of 2001, with the ascending beams standing in for the fallen Twin Towers. Each is produced by 44 xenon bulbs with 7,000-watt intensities. Their light can be seen from 60 miles away. From closer up, onlookers often notice small flecks, dancing amid the beams like gentle flurries of snow. Those flecks are birds. Thousands of them.

This annual ritual unfortunately occurs during the autumn migratory season, when billions of small songbirds undertake long flights through North American skies. Navigating under cover of darkness, they fly in such large numbers that they show up on radar. By analyzing meteorological radar images, Benjamin Van Doren showed that Tribute in Light, across seven nights of operation, waylaid about 1.1 million birds. The beams reach so high that even at altitudes of several miles, passing birds are drawn into them. Warblers and other small species congregate within the light at up to 150 times their normal density levels. They circle slowly, as if trapped in an incorporeal cage. They call frequently and intensely. They occasionally crash into nearby buildings.

It’s an excellent article, although it’s probably not surprising that a man would write an article condemning light pollution without apparently thinking about the relationship of women to walking outside in the dark. To be a woman in today’s urban environments is to be crossing streets so that you can walk under streets lights so that you feel safer.

Do street lights reduce crime?

The most often cited 2015 study out of the UK says no. But a subsequent study out of the University of Chicago Crime Lab, U-Penn and the University of Oregon, says yes:

The LIGHTS study found that the developments that received new lights experienced crime rates that were significantly lower than would have been the case without the new lights. Among other findings, the study concluded that increased levels of lighting led to a 36% reduction in “index crimes” — a subset of serious felony crimes that includes murder, robbery and aggravated assault, as well as certain property crimes — that took place outdoors at night in developments that received new lighting, with an overall 4% percent reduction in index crimes.

I am guessing it would be difficult to conduct a well-designed study to measure how much keeping the lights on at businesses at night prevents or reduces burglaries, but it makes sense that burglars would choose to break into dark businesses (and homes) over well-lit ones.

To speak convincingly about light pollution to a wide swath of the population, academics would have to, at the very least, show that they gave real-world issues such as these some thought.

Otherwise, business owners would look at you with disbelief and say, “It’s all well and good that you want to save budgies and bats, and people who want to see the Milky Way at night, but I’ve got a business to run and protect.”

Nonetheless, Yong’s article is interesting and very well done, and suggests avenues for at least beginning to meld light and sound pollution considerations into urban planning.

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