Link between La Niña, Climate Change, and Air Quality

• Research from the National Institute of Advanced Science (NIAS) shows that La Niña and climate change are closely linked to air quality.

• Last winter (2022-23) saw Delhi experiencing its best air quality in a decade, due to La Nina.

• The delayed onset of La Niña this Year and a late monsoon retreat are expected to worsen air quality in North India, particularly in Delhi, during the upcoming winter.

Key impacts include:

• Extended Poor Air Quality: A slower monsoon withdrawal will lead to high humidity, calm winds, and reduced atmospheric mixing, trapping pollutants like PM2.5 and PM10 in the air.

• Stubble Burning: If stubble burning coincides with La Niña’s delay, pollution levels could spike, particularly in November.

• Weaker Monsoon Effects: A delayed La Niña could reduce wind strength and cyclonic activity, hindering the dispersion of pollutants and worsening air quality.

• Health Risks: Increased focus is needed on toxic pollutants like PM2.5, which pose greater health risks than the traditionally emphasized PM10.

• Uncertainty of La Niña: If La Niña strengthens by December, air quality may improve by January. However, further delays could prolong the pollution crisis.

(NOTE: Refer topic no. 23 of MAY Monthly magazine for details on EL NINO, LA NINA, ENSO, IOD)