Why is India Covered in a Haze One Year and Not the Other?

Why in News?

• The ongoing COP28 in Dubai directs global attention to climate change. A significant debate on fossil fuels at the conference emphasises the intricate connection between air pollution and climate change.
• Therefore, there should be an urgent need for a collective commitment to cleaner air as a global priority.

The Air Quality Crisis in Delhi

• In November 2023, New Delhi faced an alarming deterioration in air quality, reaching on unprecedented levels.
• The city experienced a dense haze, resembling a dark mushroom cloud, with a record-high PM2.5 level of 243 ug/m3, marking a staggering 50% increase from the previous year.
• The severity persisted for a record 15 days, despite reduced stubble burning and stringent control measures under GRAP (Graded Response Action Plan).

The Paradox of Factors Affecting Delhi’s Air Quality

• Air Pollution Despite Low Stubble Burning
  • Despite a significant decrease in stubble burning compared to the previous year, Delhi's air quality remained poor.
  • It raises questions about the primary cause of the November pollution haze.
  • Another curious data point came from the advanced version of the NIA-SAFAR model run by the National Institute of Advanced Studies.
  • Despite November 2023 having the lowest stubble-burning count in the last several years, the monthly share of stubble burning in Delhi’s PM 2.5 was at the highest (>15 per cent) with a peak of 43 per cent on November 3.
  • The model’s results indicate that even relatively low amounts of stubble burning made a big impact on Delhi’s air quality in this peak fire month.
  • On the contrary, November 2022 was the least polluted in almost a decade and a higher amount of stubble burning did not make a big impact.
  • This is a paradox scientists ought to answer for the benefit of policymakers.
• Decline in Air Quality Despite Control Measures and GRAP: The Graded Response Action Plan (GRAP) and other measures in Delhi were stringent, yet the air quality witnessed a drastic decline, prompting a closer examination of contributing factors.

What Could be the Potential Reasons Behind Air Pollution in Delhi?

• Unintended Shifts in Weather Patterns
  • In India and across the globe, unusual natural changes are wreaking havoc on communities that previously never faced such events.
  • Climate scientists call it a new normal. Although more research is needed to firmly establish such connections, there are enough indications to believe that the new trends not only in Delhi’s air quality but across India have links with climate change.
  • More complex is the fact that these natural shocks are not uniform and their impact differs from one climatic zone to another.
  • Weather Conditions and Smog Canopy Unusual shifts in weather patterns, exemplified by the smog canopy breaking after rain, suggest a more complex relationship between weather conditions and air quality.
• Triple Dip in La Nina (2022)
  • The triple dip in La Nina in 2022 played a decisive role in improving Delhi's air quality by preventing winter stagnation conditions, highlighting the influence of climate patterns on pollution levels.
  • This year has seen the opposite so far. La Nina has gone, and we have entered the El Nino period. We are not sure what surprises are in store.
• El Nino Period (2023)
  • The shift from La Nina to El Nino in 2023, coupled with calm wind conditions, contributed to the accumulation of pollution in Delhi, indicating the dynamic interplay between climate factors and air quality.
• Calm Wind During November 2023
  • Contrary to last year, Delhi witnessed relatively calm wind conditions during November 2023 with limited and weaker western disturbances not having much impact beyond two to three days.
  • Also, unlike previous years, there were no frequent spells of rain.
  • This, coupled with the mainly dry weather, helped in the accumulation of pollution with little dispersion.
  • The north-north-west wind speed for a prolonged period facilitated the transport of biomass-burning particles into Delhi and surrounding regions.
• Transport Sector: The best indigenous AQ model data suggests that on average, the transport sector contributed about 30 per cent of PM2.5 in November 2023 and around 43 per cent from other internal sources.

 Way Forward

• Air Shed Approach: There is a need for an air shed approach to tackle the root causes of deteriorating air quality, moving away from superficial solutions and geoengineering.
• Moving Beyond Cosmetic Fixes and Geo-engineering: A shift from temporary fixes is required emphasising the need for comprehensive, science-driven strategies to combat air pollution.

Conclusion

• The intertwined challenges of climate change and air quality highlight the necessity for global cooperation and holistic strategies to mitigate the impact on the planet's health and well-being.
• Emergency episodes, in all probability, are set to increase unless several drastic, science-backed steps are taken to target the emissions at the source.

Q1) What is air pollution and its causes and effects?

It is the contamination of air by harmful gases, dust and smoke which affects plants, animals and humans drastically. There is a certain percentage of gases present in the atmosphere. An increase or decrease in the composition of these gases is harmful to survival.

Q2) What is the difference between PM2.5 and PM10 particles?

Dust from roads, farms, dry riverbeds, construction sites, and mines are types of PM₁₀. Coarse (bigger) particles, called PM₁₀, can irritate eyes, nose, and throat. Fine (smaller) particles, called PM_2.5, are more dangerous because they can get into the deep parts of lungs or even into blood. 

Source: The Indian Express