Human-caused climate change drives record sea temperatures across Europe

Human-driven climate change was the primary factor behind unprecedented sea temperatures recorded across large parts of Europe this summer,

LONDON: Human-driven climate change was the primary factor behind unprecedented sea temperatures recorded across large parts of Europe this summer, according to a new scientific analysis that warns of growing risks to marine ecosystems, fisheries and coastal communities.

The study by the World Weather Attribution (WWA) group found that global warming has significantly increased the intensity of marine heat affecting the Mediterranean, western European waters and the seas surrounding Britain and Ireland.

Europe’s seas have experienced extraordinary warmth alongside the extreme summer heat recorded across the continent. In July, the Mediterranean’s average sea-surface temperature reached around 27 degrees Celsius, making it the hottest July on record. Temperatures were even more extreme in some localized areas, with an offshore buoy near Mallorca registering approximately 33°C in early August.

Researchers estimate that human-caused climate change has already added about 2°C of warming to the Mediterranean and roughly 1.4°C to western European seas. The findings are based on established attribution methods used to determine how much climate change contributes to extreme weather and temperature events.

Claire Bergin, a climate scientist at Ireland’s Maynooth University and a co-author of the analysis, said the continuing rise in marine temperatures could fundamentally alter ecosystems on which coastal populations depend.

The researchers said warmer seas could affect not only marine biodiversity but also the economies and livelihoods of communities that rely heavily on fishing, tourism and other coastal activities.

Extreme temperatures linked to climate change

The WWA analysis concluded that the peak temperatures observed this year in parts of the eastern and western Mediterranean, as well as along the Bay of Biscay and the Iberian coast, would have been virtually impossible in a world without human-induced global warming.

The situation was also unusual in the Celtic Sea, located between Britain and Ireland. According to the study, the most extreme temperatures observed there would have been expected only around once every 100 years under climate conditions unaffected by human activity.

Marine heatwaves are becoming an increasingly important consequence of a warming planet. When ocean temperatures remain unusually high for prolonged periods, they can place severe stress on marine organisms and alter the physical and biological conditions of entire ecosystems.

The analysis estimated that around 90% of the Bay of Biscay and approximately 80% of the western Mediterranean experienced marine heatwave conditions this year. Without the warming caused by human activities, researchers estimated that the affected areas would have been closer to about 40%.

Threat to marine ecosystems

Scientists say prolonged periods of unusually warm seawater can trigger widespread ecological disruption. Species that are unable to tolerate higher temperatures may experience stress, reduced reproduction or mass mortality.

Coral communities and other temperature-sensitive organisms are particularly vulnerable, while changes in the distribution and abundance of marine species can disrupt food chains. Such changes may ultimately affect seabirds, marine mammals and fishing communities that depend on healthy ocean ecosystems.

John Bruno, a marine ecologist at the University of North Carolina, said some marine species were already shifting their ranges toward cooler waters. However, he cautioned that not every species would be capable of adapting quickly enough to the changing conditions.

Researchers are increasingly concerned that the pace of ocean warming could exceed the ability of many organisms to adapt or migrate to more suitable environments.

Wider consequences for coastal regions

The impact of warmer seas is not limited to marine life. Higher sea-surface temperatures can increase moisture in the atmosphere, contributing to higher humidity and warmer nights in coastal areas.

Scientists also warn that unusually warm ocean waters can provide additional energy and moisture for certain weather systems, potentially contributing to more intense storms under suitable atmospheric conditions later in the year.

The broader trend is linked to the accumulation of greenhouse gases in the atmosphere, primarily as a result of burning coal, oil and gas. According to the World Meteorological Organisation, global temperatures are now around 1.4°C above pre-industrial levels.

This elevated global temperature baseline means that weather systems capable of producing heatwaves are operating in a significantly warmer environment than they did decades ago.

The latest findings add to a growing body of scientific evidence showing that climate change is affecting not only temperatures over land but also the oceans. Since the seas absorb much of the excess heat generated by global warming, rising ocean temperatures are becoming a major indicator of the changing climate.