The rising urban noise pollution will become a top emerging environmental threat along with frequently raging wildfires and shifts in seasonal events, the United Nations (UN) said on Thursday, urging governments to initiate action immediately.
While noise pollution in European countries alone leads to 12,000 premature deaths annually, raging wildfires consumed more than 4 million square kilometers of the Earth's land surface from 2002 to 2016, equivalent to the size of the entire European Union.
Climate change caused by human activities has also significantly altered phenology, disrupting natural rhythms in plants and animals and affecting their abundance in nature, said the fourth edition of the United Nations Frontiers Report. As a result, the reproduction cycles and the migratory patterns of insects, birds and amphibians have been adversely impacted.
"Urban noise pollution, wildfires and phenological shifts – the three topics of this Frontiers report – are issues that highlight the urgent need to address the triple planetary crisis of climate change, pollution and biodiversity loss," said Inger Andersen, executive director of the UN Environment Programme.
Bring down the noise
Environmentalists have frequently warned about the consequences of wildfires and shifts in weather patterns on humans and wildlife. However, the focus on noise pollution remained primarily muted, especially in the Global South.
As cities grow, noise pollution is identified as a top environmental risk, the report states. "High levels of noise impair human health and well-being – by disrupting sleep or drowning out the beneficial and positive acoustic communications of many animal species that live in these areas."
Data collated from various sources in the report shows cities in three neighboring Asian countries having the highest traffic decibel level. Bangladesh's capital Dhaka is the loudest city, with noise levels ranging from 57 to 119 decibels, followed by India's Moradabad and Pakistani capital Islamabad.
According to the World Health Organization (WHO), road traffic noise levels should be at a maximum of 53 decibels during the day, evening and night, and restricted to 45 decibels during night time.
However, a large number of people, including vendors and the homeless, live and sleep on pavements in many developing countries, getting exposed to continuous traffic noise. Developed regions such as Europe, which has strong policies to control noise pollution, have around 22 million people suffering from noise irritation.
The report has urged urban planners to rethink mobility and create more green spaces and policies to bring down the rising decibel levels.
Increase in wildfires intensity and frequency
According to the report, wildfires will become "more frequent and intense and last longer," taking into grip areas that were previously unaffected.
The report said that land-use changes associated with agriculture, deforestation and urban development drive substantial changes to fire patterns in a wide range of ecosystems.
Land clearing for agriculture and deforestation has led to an increase in wildfires in the rainforest of the Amazon, which rarely witnessed such incidents. Major wildfires in California are fueled mainly by rapid urbanization along the edges of forests.
The massive wildfire in Australia in 2018 and 2019 triggered by global warming burnt more than 24 million hectares of forests and adjoining areas. The incident wiped out wildlife to the extent that the country declared koalas locally extinct.
These large wildfires create their own unique weather system, creating storms and lighting up fires in nearby areas, a phenomenon frequently witnessed in the United States and Australia.
"Extremely intense wildfires can trigger thunderstorms in smoke flumes that aggravate fires through erratic wind speeds and generate lightning that ignites other fires far beyond the fire front, a hazardous feedback loop," said the report.
The report seeks the development of prevention and response management approaches to prevent wildfires, including adopting methods used by traditional and indigenous communities to douse fires in ecologically sensitive zones. Researchers also recommend developing remote capabilities through satellites and radars.
Confusion caused by changes in nature's calendar
The report also raised concerns about ecosystem-disrupting phenological mismatches from the late-blooming of cherries to the declining availability of caterpillars during the hatching period of great tits birds.
"Phenological shifts occur when species shift the timing of life cycle stages in response to changing environmental conditions altered by climate change. The concern is that interacting species in an ecosystem do not always shift the timing in the same direction or at the same rate," said the report.
A similar phenomenon happens in the agriculture sector, with crops responding to seasonal variations affecting food production. The report cited a series of examples, including the iconic 4,300-kilometer migration of monarch butterflies to the struggle of great tit birds to get enough supply of caterpillars to feed their newborns.
"The only way to effectively reduce damages from mismatched phenological shifts worldwide is to reduce carbon dioxide emissions rapidly," the report said.
The first edition of the Frontiers Report published in 2016 warned about the looming threat of zoonotic diseases. Four years later, because of government inaction, the world today is witnessing the COVID-19 pandemic caused by zoonosis.
The fourth edition of the report has been launched around two weeks ahead of the UN Environment Assembly, which is scheduled to begin on February 28 in Nairobi, Kenya. Governments at the summit will decide on actions required to deal with the existing and looming threat to humans and wildlife.
(Cover: Fewer vehicles are seen on the street as the government imposed restrictions on public movement after the number of COVID-19 cases increased in Dhaka, Bangladesh, April 14, 2021. /Reuters)