In one of the more unlikely developments during Nobel Prize season, Science magazine has thrown a dash of cold water on this year's physics Nobel.
This year's physics laureates, Shuji Nakamura of UC Santa Barbara and Isamu Akasaki and Hiroshi Amano of Nagoya University, Japan, were recognized for inventing "a new energy-efficient and environment-friendly light source – the blue light-emitting diode (LED)," which allows white light to be "created in a new way," the Nobel committee declared. "With the advent of LED lamps we now have more long-lasting and more efficient alternatives to older light sources."
Here's the rub: Ecologists have become increasingly concerned that LED lighting threatens the environment by increasing light pollution. In other words, whatever benefits arise from using less energy to produce light might well be canceled out, or even exceeded, by its negative impacts.
As Science explains, "moths, flies, and other insects are drawn much more strongly by the spectrum of light from LEDs than the yellow glare of sodium-vapor bulbs." You might think that's good to the extent it eliminates a nuisance around your veranda at night, but it's not.
Science bases its report on findings by two New Zealand researchers published in the latest issue of Ecological Applications, a journal of the Ecological Society of America. The researchers found that LED lights attracted 48% more nocturnal flying insects than old-style lamps. This is worrisome for several reasons, they say. For one thing, the higher attraction will leave some insects more exposed to predators, throwing the food chain out of balance.
Moreover, industrial and urban expansion will introduce LED lighting into insect habitats thus far unaffected by light pollution. The LED lights might attract species whose spread is extremely undesirable.
Chief among these is the gypsy moth, an invasive pest whose arrival in new regions leads to "defoliation affecting productivity ... and local extinction of other Lepidoptera" (moths and butterflies). Many countries already monitor ships for infestations of gypsy moth eggs, but "a transition to white LEDs at, or near, ports may elevate the risk of egg masses moving on a transoceanic pathway, which potentially increases the risk of establishment in new regions."
White LEDs are typically manufactured by applying a coating that changes the blue light emitted by the LEDs for which the Nobel was awarded this week, resulting in a whitish glow. The New Zealand researchers found that the color change isn't enough to reduce the ecological hazard.
They say more study is needed to find ways to moderate the bad effects of LED lighting, but now that the invention has been heralded by the Nobel committee as the sort of "invention of greatest benefit to mankind" that the prizes aim to celebrate, the opportunity for further study may have been dealt a blow.