The oceans are warming nearly twice as rapidly as they did in 2005, according to a report from AFP. Over 20% of the world's ocean surface has faced severe heat waves in 2023, as noted by the European Climate Change Service, Copernicus.

During a video conference presenting the eighth Copernicus report on ocean conditions, oceanologist Karina von Schuckmannn highlighted that ocean warming marks a critical point in climate change. She pointed out that the warming trend has been ongoing since the 1960s, with the current rate being double that of previous decades.

Since 2005, the oceans have warmed by 1.05 watts per square meter, while earlier decades saw an increase of only 0.58 watts per square meter. Reports from the UN-mandated GIEC Enterprise Center in 2019 suggested that ocean warming could be more than twice as fast as it was in 1993.

The significant warming can be attributed to the oceans absorbing over 90% of the excess heat in the planet's climate system since 1970, a direct result of greenhouse gas emissions from human activities. Covering 70% of the Earth's surface, the oceans play a vital role in regulating the climate. Warmer waters contribute to the development of hurricanes and storms, which can lead to severe destruction and flooding.

The increasing frequency of heat waves is a growing concern, with 22% of the world's oceans experiencing at least one severe or extreme heat wave this year. These waves are becoming more common, lasting an average of 40 days annually—double the duration seen before 2008. The northeastern Barents Sea is reportedly in a continuous state of heat wave, according to Von Schuckmann.

In August 2022, the water temperature around the Balearic Islands hit a record 29.2 degrees Celsius, marking the highest temperature recorded in 40 years. Additionally, the Mediterranean experienced a heat wave that penetrated as deep as 1,500 meters below the surface.

Heat waves contribute to species migrations, episodic mass die-offs, and the degradation of ecosystems, affecting food availability. Furthermore, they disrupt fish reproduction, which has consequences for fishing industries. The report also indicates a rise in ocean acidity, which has increased by 30% since 1985. The oceans absorb approximately a quarter of the carbon dioxide produced by human activities, and this increased acidity threatens the skeletal structures and shells of marine organisms.