The air quality in Delhi has been a major topic of discussion for some time now. The rapid deterioration of the city's air is a clear indication of broader changes in the global climate.
As of Monday, Delhi's average Air Quality Index (AQI) worsened to the 'severe plus' category with the city recording an AQI of 484.
Meanwhile, the situation was notably different in southern cities. While the national capital struggled to breathe, Chennai and Bangalore recorded much better air quality, according to a report by Times Now.
As of November 15, Chennai's AQI was 45 ('Good') and Bengaluru's AQI was 50 ('Good'), according to CPCB data. Why is this the case?
Bengaluru benefits from several factors that help maintain clean air. The city is rich in greenery, with parks, gardens, and tree-lined streets that absorb pollutants. Its weather also plays a role - winds and frequent rainfall help disperse pollutants, improving air quality.
Additionally, Bengaluru's economy is driven by IT and services, rather than heavy industry, leading to fewer emissions. The city's focus on expanding green spaces and promoting public transport has further helped reduce pollution.
Chennai’s clean air is due to different reasons. Coastal winds help clear the air, and the city has less industrial activity, which reduces pollution levels.
Why is Delhi air so bad?
Delhi’s air quality suffers from several causes including emissions from industries, construction sites and thermal power plants.
Overpopulation also contributes to higher pollution, with more vehicles and waste adding to the problem. Many of the city's older vehicles release harmful gases, and construction work generates dust, especially in dry conditions.
Next, farmers in neighbouring states like Punjab, Haryana, and Uttar Pradesh burn crop stubble, releasing large amounts of smoke into Delhi’s air. In winter, cold weather traps pollutants, causing smog to linger.
Other cities also have varying AQI levels. Kolkata has an AQI of 222 ('Poor'), Noida has 316 ('Very Poor'), and Gurugram has 304 ('Very Poor'). Ahmedabad’s AQI is 144 ('Moderate'), while Mumbai and Hyderabad have AQIs of 133 ('Moderate') and 101 ('Moderate'), respectively.
As Delhi's AQI worsens to 'severe plus,' GRAP IV measures have been enforced. First implemented in 2017, the GRAP outlines anti-pollution actions based on the severity of air quality. These include tighter pollution controls, a truck entry ban, and the suspension of public construction projects.