Unprecedented ocean temperature records are being shattered worldwide, leading to potentially severe repercussions for the planet's well-being, climate scientists said over the weekend.
"In the last few months, global ocean temperatures have been way above anything we have seen," said Colin Price, head of Tel Aviv University's PlanNet Zero. "We do not really understand why, making it confusing and somewhat scary."
He said oceans are 70% of the planet and, therefore, significantly impact climate, "so some of the extreme weather we are seeing may be related to ocean heatwaves."
Recent data from the Copernicus Climate Change Service (C3S) revealed that the average surface temperature of the world's oceans had reached an all-time high of 20.96°C, surpassing the previous record of 20.95°C set in 2016, media reported. Copernicus data goes back to 1979.
Price said this trend would likely continue, especially given that such high temperatures are typically observed in April rather than August.
Danger of rising ocean temperatures
Specific regions are experiencing alarming heat spikes.
The Mediterranean Sea recorded its highest-ever surface temperature of 28.71°C last week, according to a maritime research center in Spain. In the waters around the Florida Keys, temperatures have soared to levels that some scientists compared to a hot tub, peaking at just over 38°C, potentially setting a new world record.
The National Oceanic and Atmospheric Administration (NOAA) reported that the North Atlantic is experiencing possibly its warmest conditions ever recorded. Highs in the Atlantic are usually observed in September, meaning temperatures could increase further until the end of next month.
"What we're seeing is a massive increase," Gregory C. Johnson, an oceanographer at NOAA, told CNN. "It's about 15 years worth of the long-term warming trend in a year."
The Intergovernmental Panel on Climate Change (IPCC) revealed that marine heatwaves have doubled in frequency between 1982 and 2016. These heatwaves have grown in duration and intensity since the 1980s, raising concerns about the escalating impact on marine ecosystems and human lives.
According to Price, the oceans are critical in mitigating the climate crisis by acting as a buffer, absorbing greenhouse gas emissions contributing to global warming. This natural process becomes less efficient as the water temperature rises, leading to more atmospheric carbon.
Price used an analogy to illustrate this point, comparing it to how gas is absorbed in a cold drink like soda or beer, with more bubbles forming. When the water warms up, it loses this ability to hold as much gas and becomes flat.
Additionally, Price highlighted that hurricanes are directly fueled by ocean temperature. As the ocean temperatures rise, hurricanes become more intense. Warmer oceans also produce more water vapor, contributing to increased rainfall during storms, leading to flooding and flash floods, as seen in Beijing last week.
Inside the oceans, the impact of warming is evident as well. Corals suffer and die off when temperatures surpass a certain threshold - coral bleaching. Moreover, excessive ocean warming disrupts the migration patterns of certain species. It also fosters the spread of invasive species.
"We are heading into an El Nino year, a natural phenomenon occurring every few years," Price explained. "During El Nino years, global temperatures tend to be warmer than usual.”
He said notable instances were seen in 1997 and 1998, followed by 2015 and 2016.
“Now, we are expecting a similar pattern in 2023 and 2024,” Price continued. “El Nino contributes to the warming and may play a role in the overall warming of the oceans. However, we haven't observed such significant warming in the past El Ninos, indicating that it can't account for the entire story."
Price said climate change is the primary driver of the current warming trend.
The rising ocean heat is just the latest concerning development in a series of climate change alarms.
Recently, a report was released revealing that July was likely the hottest month in about 120,000 years, according to German climate scientists. Moreover, more than 80% of the global population experienced heat conditions that would have been statistically unlikely without human-induced climate change, according to a separate report released last week by the NGO Climate Central.
The report compared the climate shifts in July to a hypothetical world unaffected by global warming. The extensive analysis covered 4,700 cities and 200 countries. The researchers found that more than four-fifths of the world's population encountered temperatures at least three times more probable due to climate change.
"Over 6.5 billion people - 81% of the global population - experienced at least one day in July with Climate Shift Index (CSI) level 3 or higher," the report stated. "A CSI level 3 indicates that human-caused climate change made those temperatures at least three times more likely.
"At least 2 billion people felt a very strong influence of climate change on each of the 31 days in July," the report continued. "Global exposure peaked on July 10, 2023, when 3.5 billion people worldwide experienced extreme heat at CSI level 3 or higher."
The CSI system measures the impact of climate change on daily temperatures across the globe.
The report said that high temperatures highlight the widespread impact of human activities on the Earth's climate, making it crucial for countries to address and mitigate these changes to secure a sustainable future.
"The rising frequency and intensity of these devastating events are consistent with a well-established scientific understanding of the consequences of carbon dioxide emissions," according to the report. "Heat events with CSI levels 1 through 5 will continue to become more frequent and intense as long as humans continue to burn coal, oil and natural gas."
The analysis by Climate Central builds upon methodologies that have been subjected to peer review in previous research. However, the new findings still need to undergo peer review.