New Record for Sea Surface Temperatures
Global sea surface temperatures reached a new all-time high on Friday, marking a critical moment in the planet’s climate history. This spike is not an isolated incident but part of a rising trend that endangers marine biodiversity and the lives of millions who rely on the oceans for their livelihood.
The increase in sea surface temperature to an absolute record of 21.1 °C is not only alarming but also an indication that the coming months may witness even higher temperatures. This year has already seen sea temperatures reach critical levels twice, following a previous peak between January 10 and 13.
Data from the Climate Change Institute at the University of Maine show that the 21.1 °C recorded this February matches the previous record set during the Northern Hemisphere’s summer last year. These findings underscore a disturbing trend: sea surface temperatures are rising at an alarming rate year after year, clearly evident in the data. However, many prefer to look the other way.
Figure 1. Daily Sea Surface Temperature – Global
Sea Surface Temperature (SST) and Its Impact
Sea Surface Temperature (SST) is a key indicator of ocean health. Measurement methods vary, from satellites capturing data from the uppermost millimeter to thermometers measuring approximately the top meter layer. These temperatures have profound implications for marine life, affecting the habitability of species ranging from plankton to marine mammals.
Ocean warming has devastating consequences for critical ecosystems such as coral reefs. A 2 °C rise in ocean temperature could wipe out tropical coral reefs, which harbor the greatest biodiversity of any ecosystem worldwide and are essential for the livelihoods of over 500 million people.
The world’s oceans are also losing their ability to act as a shield against climate change. To date, they have absorbed 90% of the excess greenhouse gases, acting as a climate “sponge.” However, there is growing uncertainty about whether they can continue to fulfill this essential role in the future.
Immediate Action Is Required
The Global Climate Highlights 2023 report, published by the Copernicus Climate Change Service, which the European Centre runs for Medium-Range Weather Forecasts, confirmed earlier this year that 2023 was the hottest year on record, with global temperatures approaching the 1.5°C threshold set relative to the pre-industrial period of 1850–1900.
Not only did 2023 surpass the previous annual high set in 2016, but it also became the first year in which every single day exceeded 1 °C above the pre-industrial level, with nearly 50% of days exceeding 1.5 °C and two days in November surpassing 2 °C.
The report also highlights the critical role of high sea surface temperatures in global warming, with sustained record levels from April to December. The transition to El Niño, officially declared in July, played a significant role; however, it wasn’t the only factor, as high temperatures across most ocean basins significantly contributed to the phenomenon.
These points indicate that the current situation requires urgent and coordinated action on a global scale.
The fight against climate change requires not only reducing greenhouse gas emissions but also implementing systemic changes to protect and restore marine ecosystems. Ocean conservation is not merely an environmental concern—it is a critical necessity for global security.
