World Environment Day: Noise, climate change, and the disappearance of species

“Chronic and frequent noise interferes with animals’ abilities to detect important sounds, whereas intermittent and unpredictable noise is often perceived as a threat,” says a paper entitled ‘A framework for understanding noise impacts on wildlife: An urgent conservation priority’ by Clinton D Francis and Jesse R Barber in 2013.

In March 2022, UNEP executive director Inger Andersen in an opinion piece titled ‘The world’s cities must take on the cacophony of noise’ said, “Noise pollution is also a threat to animals, altering communications and the behaviour of various species, including birds, insects, and frogs.”

In June 2020, when a pregnant elephant ate a pineapple containing firecrackers and died, the Supreme Court intervened to stop the practice of scaring wild elephants with firecrackers. However, not just flagship species like elephants are affected by noise. Even the heartbeat of caterpillars speeds up when exposed to loud noise. Noise adversely affects species across amphibians, arthropods, birds, fish, mammals, molluscs, and reptiles, according to a study published by the Queen’s University Belfast titled ‘Biology Letters’ in 2019 which analysed noise exposure of over one hundred species.

The coronavirus lockdown offered a rare opportunity to study changes in birdsong in urban environments which are usually noisy and to compare with the unexpected quiet of the anthropause. An increase in bird sightings was reported in several parts of the world, including in the timing and frequency of calls.

Bluebirds have fewer chicks when they are in a noisy environment. Robins change communication patterns and sing at night in places that are noisy in the daytime.

Ecologist Pooja Choksi is carrying out her doctoral research on bird acoustics in Madhya Pradesh. Along with conservationist Purva Variyar, Pooja is also conducting a bioacoustics study in Mumbai to gauge the impact of manmade noise on vocal behaviours in bird populations. Choksi and Variyar told me, “Studies have found that populations of different birds in specific areas have resorted to adjusting their song timings in tune with anthropogenic noise patterns in order to avoid their acoustic signals from getting masked.”

Dolphins and whales communicate through a series of sounds in their own highly sophisticated language of clicks and whistles. Image: Shutterstock

Bird migration depends on a series of complicated signals which are disrupted by noise. Their mating signals, which are often auditory, are impacted by noise. Not only birds, intelligent terrestrial and marine mammals like bats, dolphins, porpoises, dugongs and whales are similarly impacted.

Bats are an intelligent species of terrestrial mammals which use sonar ‘sounds’ indistinguishable to human ears to communicate and navigate the world around them. They are severely impacted by noise from traffic. A 2020 study in the UK published in ScienceDirect found that “Both bat activity and feeding behaviour are negatively affected by traffic noise playback”.

Sound travels five times faster underwater than it does in the air. In the deep sea where light does not penetrate, sound is essential to species who live there, giving rise to the emerging field of fish acoustics to study unknown life in the darkness of the deep sea. Studies show that different types of fish make different sounds specific to activities such as mating and spawning.

The Indian Noise Pollution Rules have been interpreted by courts as important to protect people’s constitutional right to life. In 2013, India recognised dolphins and whales as non-human persons after scientific studies proved them to be an intelligent and self-aware species which deserve the same rights and liberties as human beings.

Like humans, dolphins and whales form communities. They communicate through a series of sounds in their own highly sophisticated language of clicks and whistles. Dolphins’ speech supports their navigation, mating and parenting patterns. Noise from ships and other human activities interferes, disorienting them and making them unable to find a mate. Young ones can be separated from their parents.

In September 2021, a 42-foot blue whale carcass washed up on a beach near Mumbai. In 2016, 50 people worked for eight hours to rescue a 47-foot, 20 tonne blue whale beached near Ratnagiri on the Konkan Coast. The whale was one of the few that survived, since most beached whales do not survive. As activities in the seas increase, non-human people beached on our shores have become an increasingly regular sight.

Between 2015 and 2018, in just three years, 88 dolphins, porpoises and whales were beached in Maharashtra alone.

In another part of the world, the Narwhal Whale ‘unicorn of the sea’, named for its twisted tusk up to 3 meters long, faces an existential threat as noise levels increase in an area which was largely undisturbed until recently.

In the coldest part of the world, near Greenland, Siberia and Norway and Arctic areas frequently covered by ice, where the Titanic sank when it hit an iceberg, cruise ships now criss-cross daily. Human activity has increased and includes ports, increased shipping activity, seismic surveys and mine blasts.

During the ‘anthropause’ when cruise ships were limited, studies on humpback whales by marine mammal communication expert Michelle Fournet in the Glacier Bay showed changes in the ‘whups’ which form their communication patterns.

Although humans cannot understand the language of whales, these changed call types and patterns indicate the complexity of whales’ vocal communications with each other and the disruption to their lives caused by noise from human activities.

The first controlled field experiments on noise exposure on animals, conclude, “The impact of traffic noise on wildlife needs to be considered in EIAs.”

In India, adverse effects of noise on terrestrial animals are understood through strictly enforced rules which designate all National Parks as silence zones.

A highway through the Pench Tiger Reserve in Madhya Pradesh--where Rudyard Kipling’s The Jungle Book is set--incorporates, among other measures like underpasses and overpasses to protect animals, a 4-metre high steel wall forming a noise barrier to protect animals from noise and light pollution.

However, not all roads through protected ecosystems and forests are planned with such expensive technology or are able to adequately control noise. The small stretch of 29 kilometres through the Pench Forest cost the government Rs 960 crore. There are 20,000 km of roads in India that pass through protected habitats.

Even in urban habitats, birds and animals require protection. The city of Mumbai is being reimagined and rebuilt and while we draw up plans to control climate change and aspire to lead the world, our own infrastructure and private building projects are massive contributors to noise pollution and consequent climate change.

The Government of Maharashtra recognises this. In August 2021, the state government of Maharashtra was the first in India to draw up an action plan to control the immediate crisis of climate change. While releasing the Mumbai Climate Action Plan (MCAP), Maharashtra Environment Minister Aaditya Thackeray tweeted: “While many of us believe that we have the luxury of time in climate change action, it is a false notion. This is the time to act. We must go beyond messaging and make climate change action our policy mission and personal habit, ensuring its implementation.”

Nevertheless, the MCAP failed to mention noise pollution at all. Alongside the MCAP, the Mumbai Metro Line, Coastal Road and other infrastructure projects are underway. Of these, the Coastal Road has been specifically named by a recent Intergovernmental Panel on Climate Change (IPCC) Report as ‘maladaptive’ to climate change. People have complained about noise from construction, which continues even at night.

Though Maharashtra has declared its intention to have environment as a priority area for action, when Mumbaikars are offered world-class infrastructure and housing, their construction does not follow those same standards to safeguard our collective health or the environment.

Thackeray tweeted on May 4: “I did my regular visit to the ongoing worksites of the Mumbai Coastal Road. The work is in full swing & the road is progressing as per plan. It’s always amazing to meet the engineers & officials working on this project and see their passion for this engineering marvel for Mumbai.”

UNEP Executive Director Andersen says, “As most of the world urbanises, cities are becoming an increasingly important ecosystem, not just for humans, but for biodiversity as a whole.”

In 2021, a French study found the effects of noise pollution even more damaging than air pollution, although air pollution is listed as a leading health and environmental hazard and contributor to climate change by the United Nations.

The IPCC report tells us that we can still achieve 1.5 degrees C but that our window for this is very short. India does not meet this timeline and Mumbai, which aspires to lead the world, contributes to climate change through massive infrastructure and private building without mitigation measures.

Scientific studies increasingly link noise pollution to climate change. In the global conversation on climate change, noise pollution is an important contributor which lags in attention.

Our constantly expanding cities include natural ecosystems in which humans live alongside other species of animals and birds. Noise exposure is often considered a mere annoyance rather than the serious environmental and health hazard and contributor to climate change that it is.

Noise pollution is aggravating the climate crisis in cities, forests and under water by causing grave harm to marine and terrestrial mammals, birds and animals, and leading to species loss. Species loss is a leading contributor to climate change, on land and under water.

Making Peace with Nature, a United Nations report of February 2021, examines how the different emergencies including climate change and loss of biodiversity are highly interconnected. The report tells us that “Earth’s environmental emergencies must be addressed together to achieve sustainability”.

‘Only one Earth’ is the theme on World Environment Day 2022. It is high time Indian policies and development models recognise how noise pollution contributes to species loss and climate change.

(Sumaira Abdulali is convenor, Awaaz Foundation)