Oceans nearing record heat globally as El Nino conditions begin emerging: Copernicus

A report by CSIRO (Australia's national science agency) has flagged that global ocean temperatures are approaching record highs, with El Niño conditions begi...

What Happened

A report by CSIRO (Australia's national science agency) has flagged that global ocean temperatures are approaching record highs, with El Niño conditions beginning to emerge in the Pacific Ocean.
Global sea surface temperatures in early 2026 have ranked among the highest on record, continuing a multi-year trend of ocean warming; each successive month in 2026 has exceeded historical averages by a growing margin.
Climate models from ECMWF, NOAA, and Australia's Bureau of Meteorology now align on a high-impact trajectory: a 61% probability that El Niño conditions will develop between May and July 2026, with some forecasts projecting a "super El Niño" — potentially the strongest in modern recorded history — by late 2026 or 2027.
2026 is projected to be the second-warmest year on record, driven by the compounding of background ocean warming and the emerging El Niño signal.
IMD has flagged a 35% probability of a deficient monsoon for India in 2026 (below 90% of the Long Period Average), more than double the historical base rate of 16%.

Static Topic Bridges

ENSO: El Niño and La Niña

The El Niño-Southern Oscillation (ENSO) is the most significant driver of year-to-year climate variability on Earth. It is a coupled ocean-atmosphere phenomenon centred on the tropical Pacific Ocean. Under normal (ENSO-neutral) conditions, trade winds blow from east to west along the equator, piling up warm water in the western Pacific (near Indonesia and Australia) and allowing cold deep water to upwell along the coast of South America.

El Niño (warm phase): Trade winds weaken or reverse, warm water sloshes eastward toward the Americas, sea surface temperatures in the central and eastern tropical Pacific rise anomalously. This disrupts the Walker Circulation — the east-west atmospheric circulation cell — causing anomalous sinking air (subsidence) over the Indian subcontinent, which suppresses the Indian monsoon.

La Niña (cool phase): Opposite pattern — trade winds strengthen, warm water piles further west, eastern Pacific cools. Generally associated with above-normal monsoon rainfall over India.

ENSO monitoring region: Niño 3.4 region (5°N–5°S, 120°W–170°W); El Niño declared when SST anomaly in this region exceeds +0.5°C for 5 consecutive overlapping 3-month periods
Typical periodicity: 2–7 years; events last 9–12 months on average
Super El Niño: Niño 3.4 anomaly exceeds +2°C; historically seen in 1982–83, 1997–98, 2015–16
2026 projections: some models forecast anomalies rivalling the 1997–98 event, which caused significant global weather disruption

Connection to this news: CSIRO's report and global model consensus signal that 2026 is on track to produce a strong-to-super El Niño, making understanding of ENSO mechanics and its Indian monsoon linkages directly exam-relevant.

El Niño's Impact on the Indian Monsoon

India receives about 75% of its annual rainfall during the Southwest Monsoon (June–September). The monsoon is driven by the differential heating of the Indian landmass and the Indian Ocean. El Niño disrupts this via two mechanisms: (1) It strengthens the upper-level easterly jet stream and weakens the low-level Somali jet, reducing moisture transport toward India; (2) Anomalous subsidence over the Indian region suppresses convective activity, reducing rainfall.

Historical record: Of 15 major El Niño events since 1950, India experienced below-normal monsoon rainfall in 11. However, the relationship is not deterministic — a positive Indian Ocean Dipole (IOD) can neutralise El Niño's adverse effect (as happened in 1997 and 2019).

Long Period Average (LPA) of Indian monsoon: ~88 cm (868 mm) over June–September, computed over 50 years
"Deficient" monsoon: rainfall below 90% of LPA
2026 IMD forecast: ~35% probability of deficient monsoon, versus 16% historical base rate
Indian Ocean Dipole (IOD): currently neutral in 2026; a positive IOD phase is forecast to develop by late monsoon season, which could partially offset El Niño impacts
El Niño typically suppresses rainfall most severely over peninsular India and northwest India

Connection to this news: With El Niño conditions now emerging, the risk of a below-normal monsoon in 2026 is materially elevated, with direct consequences for agriculture, reservoir levels, and food security.

Indian Ocean Dipole (IOD)

The Indian Ocean Dipole (IOD) is a climate phenomenon in the Indian Ocean, characterised by anomalous sea surface temperature differences between the western and eastern Indian Ocean. During a positive IOD, the western Indian Ocean (Arabian Sea) is warmer than normal and the eastern Indian Ocean (near Sumatra/Indonesia) is cooler. This strengthens the pressure gradient that drives moisture toward the Indian subcontinent, generally enhancing monsoon rainfall. A negative IOD has the opposite effect.

The IOD operates semi-independently of ENSO and can act as a counterweight: historically, years with both El Niño and positive IOD have seen near-normal Indian monsoon rainfall. The IOD is monitored using the Dipole Mode Index (DMI).

Dipole Mode Index (DMI): difference in SST anomaly between the western pole (50°E–70°E, 10°S–10°N) and eastern pole (90°E–110°E, 10°S–0°N)
Positive IOD threshold: DMI > +0.4°C for at least 3 consecutive months
1997 example: strong El Niño + positive IOD → India received near-normal rainfall
2019 example: El Niño conditions earlier in year + positive IOD → India received 110% of LPA rainfall
2026 status: IOD currently neutral; positive phase forecast to develop by Aug–Sep 2026

Connection to this news: Whether the developing El Niño translates into a monsoon deficit for India in 2026 will depend significantly on whether the IOD turns positive in time — a key variable to track.

CSIRO and Global Ocean Monitoring

CSIRO (Commonwealth Scientific and Industrial Research Organisation) is Australia's national science agency, established under the Science and Industry Research Act, 1949. In the context of ocean and climate science, CSIRO operates the Argo float network monitoring, maintains long-term ocean heat content datasets, and contributes to global climate model development through collaboration with ECMWF, NOAA, and the Bureau of Meteorology (BOM). Ocean heat content — the total thermal energy stored in the ocean — is a more reliable long-term climate indicator than surface temperatures alone, as the ocean absorbs over 90% of the excess heat trapped by greenhouse gases.

Ocean heat content: over 90% of excess anthropogenic heat is absorbed by the oceans
Sea Surface Temperature (SST): the top few millimetres; most directly linked to atmospheric interaction
CSIRO finding: average SST in the Australian region has warmed by ~1.08°C since 1900; 9 of the 10 warmest years on record have occurred since 2010
Global SST in early 2026: approaching or matching records set in 2023–24
Marine heatwaves: higher background ocean temperatures make marine heatwave events more frequent, intense, and prolonged

Connection to this news: CSIRO's role as a credible scientific authority in Southern Ocean and Pacific monitoring gives its El Niño emergence assessment significant weight for global climate response planning, including India's seasonal forecast updates.

Key Facts & Data

El Niño probability (May–July 2026): 61% (multi-agency consensus)
2026 projected rank: second warmest year on record (Carbon Brief analysis)
IMD 2026 monsoon: ~35% probability of deficient season (below 90% LPA); LPA ~868 mm
Historical El Niño–monsoon relationship: below-normal rainfall in ~11 of 15 major El Niño events since 1950
Niño 3.4 region SST anomaly threshold for El Niño: +0.5°C sustained over 5 overlapping 3-month periods
Super El Niño threshold: Niño 3.4 anomaly > +2°C; last super El Niño: 2015–16
CSIRO established: under Science and Industry Research Act, 1949 (Australia)
Ocean absorbs: over 90% of excess anthropogenic heat
Indian Ocean Dipole (DMI) 2026 current status: neutral; positive phase forecast by late monsoon season