El Nino sets temperature record in key Pacific zone: EU monitor

El Nino is the warm phase of the El Nino-Southern Oscillation (ENSO), a natural climate cycle characterized by unusual warming of surface waters in the central and eastern equatorial Pacific Ocean. This warming alters atmospheric circulation, specifically the Walker Circulation, causing a reversal or weakening of trade winds. For India, a strong El Nino typically correlates with a weaker Southwest Monsoon, leading to deficient rainfall and potential droughts, significantly impacting agriculture. The news highlights that temperatures in the Nino3.4 region (a critical monitoring zone between 5°N-5°S and 120°W-170°W) exceeded those of the powerful 1997/1998 and 2015/2016 events. The article notes that differing indices are used globally (e.g., Japan’s weather agency vs. Copernicus) to measure El Nino's strength, sometimes adjusting for the background warming caused by climate change to accurately assess the phenomenon's pure intensity.

The intensifying El Nino is compounding the effects of anthropogenic (human-caused) climate change, creating a dangerous feedback loop. As global ocean temperatures rise due to greenhouse gas emissions, natural phenomena like El Nino occur on a warmer baseline, making their impacts more severe. The record global average sea surface temperature of 21.05°C in September underscores the massive amount of heat absorbed by the oceans, which act as a crucial carbon sink. This exceptional heat exacerbates extreme weather events worldwide, including heatwaves, heavy precipitation, and coral bleaching. The interplay between natural variability (ENSO) and long-term climate trends is a crucial area of study for UPSC, as it determines the frequency and intensity of future climatic anomalies.

The data presented raises significant concerns regarding global climate governance and the targets set by the Paris Agreement (adopted at COP21 in 2015). The agreement aims to limit global warming to well below 2°C, preferably to 1.5°C, compared to pre-industrial levels. However, the report indicates that September was 1.63°C hotter than the pre-industrial average, and experts warn that a sustained breach of the 1.5°C limit is imminent, likely driven by the current El Nino. The concept of an overshoot—temporarily exceeding the temperature target—is becoming a central focus in climate policy. The challenge for global governance, coordinated by bodies like the United Nations Framework Convention on Climate Change, is to implement rapid and deep emission reductions to minimize the duration and magnitude of this overshoot. For UPSC Mains, candidates must analyze the implications of failing to meet these targets and the urgent need for enhanced mitigation and adaptation strategies, particularly for vulnerable developing nations.