COP-31 Underway: 2026 Set to Exceed Threshold Triggered by El Nino Warming

Key Takeaways:

• Global warming: COP31 deliberations coincide with concerns that 2026 could rank among the warmest years, with global temperatures approaching or exceeding 1.5°C above pre-industrial levels.
• El Niño: A strong to very strong El Niño continues, with the weekly Niño 3.4 index at +2.3°C and the Relative Niño 3.4 index at +2.75°C.
• IOD and MJO: The positive IOD remains active at +0.75°C, while the MJO is expected to weaken over the Indian Ocean during the third week of November.
• 2027 outlook: El Niño is expected to retain strength into early 2027, with a possible collapse not anticipated before mid-2027.

COP31 (the 31st United Nations Climate Change Conference) is underway at the Antalya Expo Center in Antalya, Turkey, from 09 Nov to 20 Nov 2026. El Niño-triggered warming is expected to place 2026 on the list of warmest years, crossing the threshold mark of 1.5°C.

As per the Copernicus Climate Change Service, October 2026 is likely to be the warmest October on record globally, wherein the mean global temperature is expected to be 15.35°C, about 0.9°C above the 1991–2020 average and 1.75°C above the pre-industrial era (1850–1900). The deliberations are in progress on the consequences of the ever-increasing heat index of planet Earth.

The United Nations World Meteorological Organization (WMO) has raised an alarm over the state of the global climate, warning that a very strong El Niño event will unleash extreme amounts of heat and extreme weather well into 2027. The latest WMO State of the Climate Update 2026 shows that the last 12 years have been the warmest on record, with the global surface temperature between January and September 2026 reaching 1.47°C above the pre-industrial mark.

ENSO: El Niño does not add new heat to the planet. It releases stored heat from the ocean, which is the warmest ever measured. “El Niño and indeed the state of the global climate in 2026 gives new meaning to the phrase ‘off the charts’,” said the WMO Secretary-General. The “off the charts” ocean warming due to the very strong El Niño event can be seen in the record-breaking temperatures being recorded by researchers in the Niño 3.4 region of the Pacific Ocean, where the ocean has warmed to 3.4°C above normal, as shown by the Climate Change Institute's Climate Reanalyzer data platform.

A strong to very strong El Niño is underway. However, the Niño 3.4 index, after consistently rising since the beginning of 2026, has dropped a bit. The latest Niño 3.4 index value for the week ending 09 Nov 2026 was 2.3°C. The weekly Relative Niño 3.4 index of BoM for the week ending 08 Nov 2026 was +2.75°C, a shade lower than the previous week. It has cooled slightly from the peak value of the event so far (+2.88°C). The event values are normally assessed using the long monthly Relative Niño 3.4 dataset.

IOD: A positive IOD event is underway. The IOD index for the week ending 08 Nov 2026 was 0.75°C, a shade higher than the previous week. The positive IOD is likely to continue through November and may reach neutral early next year.

MJO: The MJO is likely to remain nearly stationary over the Indian Ocean in Phases 2 and 3. However, the pulse amplitude will weaken in the third week of November. It may return to the Western Pacific/Western Hemisphere during the fag end of November 2026. Tropical cyclogenesis is favoured over the Indian Ocean during the next week.

The ENSO cycle is expected to reach its peak very soon and may sustain its strength until early next year. Its collapse is likely, but not earlier than mid-year 2027.