Bulletin highlights the deep interlink between air quality and climate change, stressing the need for holistic action to protect health, ecosystems, and economies.

Key Highlights

• PM2.5 Pollution:  Major global health risk, causing millions of premature deaths yearly.
  • Levels have declined in North America, Europe, and East Asia due to regulations but remain high in South Asia and high latitudes, driven by wildfires and industrial activity
• Shipping Emission Regulations (MARPOL VI): Curbed sulfur in marine fuels, improving health but slightly increasing global warming by reducing sulfate aerosols’ cooling effect.
• Air quality and climate change: Pollutants like ground-level ozone warm atmospheres, while climate change influences pollution through altered chemical reactions, biogenic emissions, and human activity.
• Aerosols: Dark aerosols (e.g., black carbon) absorb solar radiation, leading to warming, while brighter ones (e.g., sulfates) reflect it, causing temporary cooling.

Winter Fog Issue in North India (Highlighted by Report)

• The Indo-Gangetic Plain (IGP) faces worsening winter fog and rising air pollution due to human activity.
• Causes: 
  • Fog forms as moisture condenses on PM2.5 (from vehicles, industry, crop burning) acting as 'fog condensation nuclei' (FCN). 
  • Temperature inversions trap these pollutants, prolonging dense fog. Urbanization, brick kilns, and ammonium emissions intensify this. 
• Consequences: Major transportation delays and severe health issues like asthma, with toxic compounds in fog water being a concern.