Oceans Reach Highest Ever Surface Temperature, Breaking 2016 Record
The world’s oceans have recorded their highest ever surface temperature, with experts predicting that the warmest month for oceans is yet to come. This alarming development is largely attributed to climate breakdown resulting from the burning of fossil fuels, which continues to heat up the oceans.
According to the Copernicus climate modelling service, the global average daily sea surface temperature (SST) reached 20.96 degrees Celsius this week, surpassing the previous record of 20.95 degrees Celsius set in 2016. Scientists warn that this record is likely to be broken again, as oceans are typically at their hottest globally in March, not August.
Dr Samantha Burgess, from Copernicus, expressed concern about the steady increase in ocean temperatures, stating, “The fact that we’ve seen the record now makes me nervous about how much warmer the ocean may get between now and next March.”
While the El Niño weather phenomenon, observed in 2016, may contribute to the rising temperatures, experts argue that climate breakdown and the warming atmosphere exacerbate these weather patterns.
“The more we burn fossil fuels, the more excess heat will be taken out by the oceans, which means the longer it will take to stabilize them and get them back to where they were,” Burgess explained to the BBC.
In a contrasting move, the British prime minister, Rishi Sunak, recently authorized the issuance of more than 100 new oil and gas licenses in the North Sea, contradicting the advice of climate experts.
Apart from regulating the climate and absorbing heat, oceans also act as carbon sinks and provide relief through cool air blown off the sea. However, as oceans warm, their beneficial impacts diminish, and warm waters become less capable of absorbing carbon dioxide, leading to an increase in greenhouse gas concentrations in the atmosphere. Moreover, the warming of oceans contributes to ice melting and sea-level rise.
Sea surface temperature measurements, derived from ships, date back more than 150 years and are essential records for understanding climate change. Over the past 40 years, satellite and buoy measurements have also been available, revealing that global mean sea surface temperatures have increased by nearly 0.9 degrees Celsius over the full period of the records. The increase over the past four decades alone amounts to approximately 0.6 degrees Celsius. The latest five-year average is around 0.2 degrees Celsius higher than the average between 1991 and 2020.
Parts of the Arctic Ocean, the Baltic Sea, the Black Sea, and portions of the extra-tropical Pacific are experiencing some of the fastest warming rates. This year has seen several marine heatwaves worldwide, including in the UK, Ireland, and the unprecedented temperatures of 38 degrees Celsius off the coast of Florida.
A study in 2019 revealed that marine heatwaves are becoming more frequent, with the number of heatwave days having tripled compared to the past few years. Additionally, the number of heatwave days increased by more than 50% between 1925-1954 and the 30-year period leading up to 2016. Scientists associated these heatwaves with the destruction of marine life, similar to how wildfires ravage vast forested areas.
The damage caused by these hotspots is not only detrimental to marine ecosystems but also poses threats to humanity, which depends on the oceans for oxygen, food, storm protection, and the removal of climate-heating carbon dioxide from the atmosphere.