In the plains of the Ganges, 600 million Indians suffer the effects of climate change and air pollution in cities such as Varanasi, one of the most polluted cities in the world according to the PM2.5 particle concentration.
Alfredo Boada Mola
There are enough fine particles in the air in this big city in the Northern Indian State of Uttar Pradesh to classify it as one of the most polluted cities on the planet, according to the World Health Organization (WHO) list in 2018.
It’s not just Varanasi, a city that is home to 1.2 million people along the shores of the most sacred river in India – the Ganga or Ganges, that has this problem.
Kanpur, Faridabad, Gaya and Patna are four other cities that lie in the Ganges lowlands and that take the first five places on the WHO list.
With a diameter of 1/25th of a human hair, these particles cause cardiovascular and respiratory diseases, including cancer.
Cities in India also occupy 11 of the first 15 places on the list of most polluted cities on the planet according to an even bigger pollutant, PM10 particles.
The impact of this air pollution is not limited to human health. Several of the gases lead to features of the greenhouse effect; they trap the sun’s heat and raise the temperature of the Earth.
Recent studies imply that these pollutants are changing both the local and global climate. According to experts, temperatures are rising in the Indo-Gangetic Plain, and the monsoon is becoming more uncertain.
“Many of the air pollutants also have an effect on climate”, days Erika von Schneidemesser, who studies the link between air pollution and climate change at the Institute for Advanced Sustainability Studies (IASS) in Potsdam.
According to the WHO, as the air quality decreases, more people will be at risk of suffering stroke, cardiac diseases, lung cancer and acute and chronic respiratory diseases.
Air pollution can also cause an increase or decrease in temperature and change rain patterns.
Particles such as dust, sea salt and ash suspended in the air are known as aerosols. Some aerosols absorb more height from the sun, whereas others have reflective properties, causing temperatures to drop.
“Aerosols can cause significant changes in cloud properties,” says Sachchida Nand Tripathi, Professor and Head of the Civil Engineering Department at the Indian Institute of Technology in Kanpur.
Its increase in the atmosphere is slowly weakening the Indian monsoon, and can redistribute the rain in a short period of time.
The majority of Indian cities that are among the 20 most polluted in the world are located in the Indo-Gangetic Plain, which extends from Pakistan in the west to Bangladesh in the east.
Tripathi adds that “The Himalayas are to the north of the Indo-Gangetic Plain, and the Deccan Plateau is to the south. This creates a valley effect and causes the air to stagnate.”
Winds from the northwest that blow across the region spread the air, polluting across the Indo-Gangetic Plain. “The winds can also spread the pollution from Central Asia and Pakistan all the way to areas of Punjab,” says Tripathi. (PL)
(Translated by Lucy Daghorn) – Photos: Pixabay