Brian Barton
Delhi, the Indian capital, is often ranked as one of the most polluted cities in the world. The pollution is largely blamed on the agricultural burning carried out by nearby farmers to clear their fields for ploughing. This, combined with factory emissions and traffic fumes, leads to a blanket of smog over the city. To tackle this, the government has decided to stop the refuelling of old diesel and petrol cars, turn barren land into forests, and encourage university students to get involved in planting.
| Characteristics | Values |
|---|---|
| Reason for Delhi's pollution | Agricultural burning by nearby farmers to clear fields for ploughing, factories, and traffic fumes |
| Other factors | Cooler temperatures and slow-moving winds trap pollutants in winter |
| Action taken by Delhi's environment minister | Stop refuelling diesel and petrol cars older than 10 and 15 years, respectively, after March 31, 2025 |
| Other decisions | Turn barren land into new forests and get university students involved in planting |
Explore related products
What You'll Learn
Agricultural burning by farmers to clear fields
Delhi's hazardous pollution levels have been blamed on several factors, including agricultural burning by nearby farmers to clear fields for ploughing. Every year, farmers burn large areas of agricultural land to make way for new crops, sending up plumes of toxic smoke that contribute to the city's air pollution. This practice, known as slash-and-burn agriculture, has been used for thousands of years to clear land and make it suitable for crops and livestock. While it has been historically sustainable in areas with low population densities, the increasing population has accelerated deforestation, contributing to the depletion of the Earth's carbon reservoirs.
In the case of Delhi, the nearby farmers burn the biomass of trees and woody plants, leaving the vegetation to dry before the rainiest part of the year. The burning results in a nutrient-rich layer of ash, making the soil fertile and temporarily eliminating weed and pest species. However, after a few years, the plot's productivity decreases due to nutrient depletion and weed and pest invasion, causing farmers to abandon the field and move to a new area. This cycle of clearing land by fire contributes to the air pollution that, according to the World Health Organization (WHO), kills 7 million people annually, including 650,000 children.
Ironically, agricultural burning can reduce water retention and soil fertility, requiring farmers to invest in expensive fertilizers and irrigation systems. Additionally, black carbon released during burning can modify rainfall patterns, disrupting the weather events necessary for agriculture. Experts are sounding the alarm about the harmful effects of crop burning, and alternatives are being promoted in various countries. The Climate and Clean Air Coalition, for example, works with regional networks to provide farmers with information and assistance in accessing alternatives to crop fires.
In conclusion, agricultural burning by farmers to clear fields is a significant contributor to Delhi's pollution problem. The practice has negative consequences for the environment and human health, and alternatives are being sought to reduce its impact. While it may be challenging to change long-established habits, education, awareness-raising, and capacity-building for farmers can help promote more sustainable land-clearing methods.
Pollution's Impact: Three Ways It Affects Our World
You may want to see also
Explore related products
Factory emissions
The types of industries that have the potential to affect air quality include chemical, textiles, cement, steel, basic metal, mining, and petroleum refineries. In Delhi, there is a large presence of these industries, with workers primarily engaged in the textiles, metal, paper, repair, food, and chemical sectors. The burning of coal in power plants, which made up 12% of Delhi's air pollution in a 1997 report, is also a significant contributor to factory emissions.
To address factory emissions, India's Supreme Court ordered the shutdown of hazardous industries, hot-mix plants, and brick kilns operating in Delhi. Other control measures include the introduction of unleaded petrol, catalytic converters in passenger cars, and the reduction of sulfur and benzene content in fuels. The Delhi government has also implemented the Graded Response Action Plan (GRAP), which triggers stricter pollution control measures as air quality deteriorates. For example, during Stage II of the GRAP, there is a ban on non-emergency diesel generators and a suspension of non-essential construction.
Despite these efforts, air pollution in Delhi remains a serious issue, with industrial activities continuing to play a significant role. The problem is further exacerbated by the large number of vehicles on the road and the burning of crops by farmers in neighbouring states, which has contributed up to 45% of Delhi's pollution during the crop-burning season. The annual smog, which traps toxic pollutants, has become an expected occurrence, severely impacting the health and lives of Delhi's residents.
Pollution's Heavy Burden: Global Weights and Measures
You may want to see also
Explore related products
Traffic fumes
Delhi's air pollution is a complex issue with multiple contributing factors, and traffic fumes are a significant part of the problem. According to India's Ministry of Earth Sciences, vehicular emissions account for almost 41% of the city's air pollution. The transport sector's emissions have been increasing, and the city's emission levels remain a pressing concern.
The Indian government has implemented measures to address the issue of vehicle emissions. In March 2025, the Delhi government announced that diesel and petrol cars older than 10 and 15 years, respectively, would no longer be allowed to refuel in the city. This decision was made to reduce the capital's hazardous air pollution levels. However, there has been resistance to this rule, with many older vehicles still on the roads.
The Supreme Court's interim order pausing the age-based ban on vehicles highlights the challenge of reducing traffic fumes in Delhi. While the ban aims to improve air quality, it has sparked public debate and controversy. The city's government, the Aam Aadmi Party (AAP), and the central authorities, the Bharatiya Janata Party (BJP), often engage in political blame games regarding Delhi's air pollution.
The National Green Tribunal (NGT) has justified the ban on overage vehicles, stating that it is necessary to protect the health of Delhi's residents. The International Agency for Research on Cancer, part of the World Health Organization (WHO), has classified diesel exhaust fumes as a group one carcinogen. The IQAir World Air Quality Report in 2021 found that no Indian city met the updated WHO safety standards for PM2.5 particulate matter.
Delhi's toxic smog season, typically during winter, contributes to the region's ranking as one of the most polluted areas globally. The city has explored emergency measures, such as stimulating artificial rain to clear the smog. However, the effectiveness of these measures remains uncertain, and Delhi continues to struggle with hazardous air pollution levels, causing adverse health impacts, particularly for vulnerable populations.
Measuring Pollutants: Techniques and Tools for Environmental Monitoring
You may want to see also
Explore related products
Slow-moving winds trap pollutants
The quality of air in a given region is significantly influenced by wind speed and direction. Wind disperses air pollution formed from both natural and anthropogenic activities. For instance, in the 1980s, studies found that wind carried sulfur dioxide from coal burning in the Ohio Valley across large distances, causing acid rain in regions of the eastern US and Canada up to a thousand miles away. Similarly, in Asia, powerful spring winds carry clouds of industrial pollutants from China across the Gobi Desert, causing massive yellow dust storms across the Korean Peninsula and parts of Japan.
Wind speed and direction data can be thought of as a map of the air quality "landscape", providing information on where air pollution originates and where it is prone to travel. Wind speed and direction measurements are vital to understanding the complex dynamics of air pollutant creation and dispersion. Upper-level winds can help transport large amounts of heat and smoke produced by fires over large distances.
However, slow-moving winds can worsen air quality by trapping deadly pollutants. Cooler temperatures and slow-moving winds worsen the situation in Delhi each winter. The Indian capital has hazardous air quality, primarily blamed on agricultural burning by nearby farmers to clear their fields for ploughing, as well as factories and traffic fumes.
A similar phenomenon occurs during a thermal inversion, when a layer of warm air traps cool air and pollution close to the ground. Thermal inversions are more common above cities where cold, dense air gets trapped in mountain basins or valleys, such as Los Angeles, Denver, and Mexico City. Some pollutants, such as ground-level ozone, are more efficiently produced in sunny, hot weather. In the summers and during extreme heat waves, ozone often reaches dangerous levels in cities or nearby rural areas.
Understanding AQI: Air Quality Index Explained
You may want to see also
Explore related products
Diesel cars over 10 years old
Delhi's hazardous pollution levels have been primarily blamed on agricultural burning by nearby farmers to clear their fields for ploughing, as well as factories and traffic fumes. To tackle this issue, the city's government has announced that diesel cars over 10 years old will be barred from refuelling in New Delhi. This decision was made at a ""marathon meeting" on air pollution, where Delhi's environment minister, Manjinder Singh Sirsa, stated that they aim to "find out the diseases and its remedies".
Sirsa announced that after March 31, 2025, vehicles older than 15 years would be refused fuel at the city's petrol pumps. This includes diesel cars over 10 years old, which have not been allowed to ply on Delhi roads for several years. To enforce this rule, "gadgets" or AI-enabled cameras will be installed at petrol pumps to identify such vehicles.
The minister also addressed the need to turn barren land into "new forests" and encouraged university students to get involved in planting drives. Additionally, all high-rise buildings, hotels, and commercial complexes in the capital must install anti-smog guns to further curb air pollution levels.
Delhi's government plans to phase out 90% of CNG-driven public transport buses by December 2025, replacing them with electric buses to promote cleaner and more sustainable transport. This includes the procurement of 3,680 e-buses by September 2025 to encourage the use of public transport.
Writing Pollution Poems: Tips and Tricks
You may want to see also
Frequently asked questions
The primary cause of pollution in Delhi is agricultural burning by nearby farmers to clear their fields for ploughing, as well as factories and traffic fumes.
Cooler temperatures and slow-moving winds worsen the situation by trapping deadly pollutants each winter.
The Delhi government has decided to stop refuelling diesel and petrol cars older than 10 and 15 years, respectively, after March 31, 2025. They will be identified with the help of "gadgets" installed at petrol pumps.
The Delhi government has decided to turn barren land into "new forests" and get university students involved in planting.
