In March 2026, the global sea surface temperature once again approached the records of 2024, despite the fact that the El Niño phenomenon is not active. According to data from Copernicus, the global average temperature was 13.94 °C, which is 0.53 °C above the 1991-2020 average and 1.48 °C above pre-industrial levels.
Arctic ice marked its historic winter minimum, while the earth’s energy imbalance reached its highest level in 65 years. This scenario concerns the scientific community, which warns that the oceans have “stepped up” in their warming.
Critical Areas
The sustained increase in ocean temperature is especially observed in:
- Subtropical and northeastern North Atlantic.
- North and South Pacific. In these regions, record values are already being recorded, anticipating an even more extreme scenario when El Niño intensifies again.
The Mediterranean as a Climate Laboratory
The Mediterranean is warming 20% faster than the global average, becoming a key area to observe the risks of climate change. The consequences are evident:
- Mass extinction of vertebrates.
- Retreat of seagrass meadows.
- Fish mortality. Additionally, the heat injects more water vapor into the atmosphere, fueling extreme precipitation events.
Main Consequences of the Increase in Ocean Surface Temperature
- Impact on marine ecosystems: massive coral bleaching and habitat loss.
- Sea level rise: thermal expansion and polar ice melt raise the waters.
- Acidification: the ocean absorbs more CO₂, altering its chemistry and affecting shell-bearing organisms.
- Stratification: hot upper layers separate from the deep ones, reducing oxygen and nutrients.
- Risk to fauna: species like tuna and sharks alter their migratory routes towards the poles.
- Extreme phenomena: more intense marine heatwaves impact marine life and coastal climate.
A Global and Silent Problem
Ocean warming, driven by the absorption of heat from greenhouse gases, alters biodiversity and threatens food security and coastal protection. Although it does not always generate alarming headlines, its cumulative effects are devastating: fewer marine pollinators, lower fishing productivity, and greater vulnerability of coastal communities.
The oceans are showing unequivocal signs of a structural change in their temperature, even in the absence of El Niño. This phenomenon not only affects marine biodiversity but also destabilizes the global climate and compromises the safety of millions of people. The challenge is clear: reduce greenhouse gas emissions and strengthen adaptation policies to face an ocean that is no longer the same.
