The Law Nina Shadow

• The delayed onset of La Niña and the late retreat of the monsoon have raised concerns regarding air quality in North India, particularly Delhi. Predictions indicate significant pollution challenges in the early winter months, with the potential for some relief in December and January, contingent on the strengthening of La Niña conditions.

Impacts of La Niña and Monsoon Variability

Climate Change and Air Quality:

• Recent studies from the National Institute of Advanced Science (NIAS) have highlighted the interplay between climate change, La Niña, and air quality. The winter of 2022-23 saw Delhi experiencing its best air quality in a decade, largely attributed to favorable climatic conditions.
• However, the uncertainty surrounding La Niña's arrival introduces challenges for air quality management.

Shift from Local to Global Factors:

• Air pollution has evolved beyond local emissions to encompass larger meteorological phenomena. Researchers advocate for a comprehensive approach that considers regional and global climate influences on air quality. This necessitates attention to large-scale atmospheric patterns, such as El Niño-Southern Oscillation (ENSO), which affect pollution distribution across borders.

The Role of PM2.5 and Policy Implications

Dominance of PM2.5:

• Policymakers must prioritize PM2.5, primarily arising from fossil fuel combustion, rather than focusing excessively on PM10, whose main source is dust. Misallocation of resources and misplaced priorities can hinder public health objectives.
• Effective policies should address the dominant sources of PM2.5 emissions for meaningful air quality improvement.

NIAS-SAFAR Model Analysis:

Concerning Projections for Winter Air Quality:

• The NIAS-SAFAR model provides a grim outlook for Delhi's air quality this winter. Factors contributing to this assessment include:
• Delayed Monsoon Retreat: A slower withdrawal of the monsoon leads to higher humidity and stagnant winds, trapping pollutants near the surface.
• Delayed La Niña Onset: The anticipated development of La Niña between September and November may result in stagnant wind conditions, worsening pollution levels in northern India.

Potential Relief in Later Winter Months:

• If La Niña conditions materialize in December and January, the NIAS-SAFAR model suggests that stronger winds and fewer clouds could improve air quality. However, a longer, more severe winter could counteract these benefits by lowering the inversion layer, which traps pollutants, thereby complicating air quality management.

The Stubble Burning Dilemma

Contribution to Pollution:

• Stubble burning in Punjab and Haryana poses a significant threat to Delhi's air quality, particularly in the absence of La Niña. Dominant north-north-westerly winds are likely to transport pollution from these agricultural practices into the city, exacerbating existing air quality challenges.

Future Projections and Climate Change Implications

Unpredictable Outcomes of La Niña:

• The possibility of La Niña arriving earlier than expected could have far-reaching consequences. The NIAS-SAFAR model indicates that an early La Niña onset could worsen air quality in the southern peninsular region but potentially improve conditions in northern India.

Climate Change and Extreme Pollution Events:

• Emerging evidence links extreme air pollution events to climate change. Local emissions are compounded by the uncertainties introduced by rapidly changing climatic conditions. A broader focus on airsheds rather than isolated cities is essential for effective air quality management.

Conclusion: Rethinking Air Quality Strategies:

• To address the multifaceted challenges of air quality in North India, it is crucial to adopt a holistic approach that incorporates larger climatic factors. This can be achieved through collaborative efforts between scientific bodies and policymakers to develop health-centric strategies and allocate resources effectively.
• As the climate continues to change, innovative and adaptable policies will be key to improving air quality for future generations.