Around this time every year, there is much talk about air pollution and noise pollution caused by Diwali celebrations. Experts, however, believe it is high time we recognised and contained light pollution.

As the city gets electrically lit up for Diwali, the shift from clay lamps to artificial festive lights is leaving a large footprint. Light pollution, where the night sky is not dark anymore due to excessive artificial lights, is the most visible repercussion.

Tiny light bulbs strung together -called serial lights or fairy lights were once restricted to wedding halls and gala events but have become commonplace, with cheap variants (often imported from China) flooding the markets. The larger implications of wasting electricity is pointed out by ecologist TV Ramachandra of the IISc. “It is not sensible to waste electricity in lighting up buildings for days when the state has an energy crisis,“ he says. “Arrogant exhibitive behaviour“ is how he describes it.

Fairy lights are the electric version of thousand-walas and ten-thousand walas -long strings of crackers that are set off, often as an announcement of one's “arrival“. One Bengalurean called the display of lights in her apartment complex “vulgar, overpowering and near-nauseating“.

Humans are not the only beings who might find lights unbearable.Science has long proved that prolonged exposure to light at night can affect the growth of trees and the natural cycles of birds and other creatures.

“We are looking at everything from an anthropocentric view,“ says HS Sudhira of Gubbi Labs, adding “other creatures can see lights that are beyond human visibility . What is affecting us could be affecting them more. But we pay little attention to this.“ While shifting from the nonpolluting cooling light of earthen lamps to heat-generating bulbs, we are creating a substantial carbon footprint too. There is no study on this in India but a few years ago, a UKbased Energy Saving Trust found that extravagant light display during Christmas and New Year led to the generation of 400kg of extra CO2.

Waste-generation comes at the tailend of every celebration and is a looming problem. “Most of them (lights and paraphernalia) are made with flimsy material and are not meant to last long,“ Sunil Sood, an energy-consultant said. So there's a high chance that lights used this year either end up in the attic or in the dump next year. This combination of thin wires, plastic and metal is, no doubt, hard to recycle.

Sood raises an important question, “why do we need to import something so unnecessary?“ The growing demand for made-inChina fairy lights has taken business away from small-scale, local craftsmen. As sustainability proponent Sandeep Anirudhan puts it, “it is important to pay attention to what we are promoting every time we buy or use something. For every choice we make, there are sustainable alternatives.“ In this case, there are locally made, handcrafted mud lamps that are fairly priced.