I love flying at night. The air is generally smoother, traffic is lighter and Air Traffic Control is less frantic even around busy air space. Over the years (I got my pilot’s license in 1996) the changes in nighttime lighting over time have been fascinating. Of course, development and suburban sprawl across the southeastern US (where I do much of my flying) means that stretches of darkness are fewer and fewer. Military bases/restricted areas such as the Savannah River Site, parks, and wetlands stand out. But there is another significant change over the last decade. A major shift in outdoor lighting is the development and deployment of high intensity LED lights. These lights are both brighter and on different wavelengths (colors) than the old sodium vapor lights. This shot over Augusta, Georgia (taken Feb 9th, 2019 from 7000 feet) very clearly shows the older orange/yellow lights versus the newer, white LED lights. While we tend not to think about it, this is one of the many ways human activities have rapidly altered the natural world. This study published in PNAS discusses how these lights have adversely impacted bird migration patterns. Other studies have shown impacts on insects, bats, and animals. There are also impacts on the animals who made these things – Humans. Human sleep patterns have also been altered by both nighttime city lighting as well as the proliferation of LED screens such as smartphones and iPads. The bright blue light given off by these devices triggers a brain response that can distort sleep patterns.
But doesn’t night lighting improve traffic safety and prevent crime? Maybe not – the studies are somewhat contradictory, and many studies suffer from abysmal statistical methodologies, as well as being somewhat tainted by their sponsorship by industries that profit from lighting. Some well structured studies such as this one in England show that nighttime lighting doesn’t do anything to reduce crime or accident rates. But this is an area ripe for serious research.
So what does this have to do with climate? It shows how something that seems as simple as putting up a street light can have cascading impacts across the human and natural world. The simple fact is that human activities do alter the environment. Classifying these alterations as positive or negative, and then evaluating if those with negative aspects are worth doing from a benefit cost standpoint are value judgements that require solid, unbiased science to inform those decisions. And this intersection between science and public policy is a place many scientists are reluctant to get involved with as it means dealing with politicians. The political process speaks an entirely different language, and uses metrics that are utterly alien and irrational in many ways. It’s probably the least fun thing I do, even though, in the end, it is the part of the work that can have the most impact.
Oh, and speaking of Big City Nights here are the Scorpions and the Berliner Philharmoniker.