Posted on 08/01/2025 7:01:12 AM PDT by Red Badger
In A Nutshell
* Marine heat waves in 2023 reached record-breaking intensity, duration, and global coverage, affecting 96% of the world’s oceans.
* The North Atlantic experienced a 525-day heatwave with a 276-year return period, and similar long-lasting events occurred in the Southwest Pacific and Tropical Eastern Pacific.
* Researchers linked these events to region-specific drivers such as reduced cloud cover, weakened wind systems, and El Niño conditions.
* Scientists suggest these extremes may represent an early warning sign of a potential climate tipping point.
=================================================================================
ZHEJIANG, China — The world’s oceans experienced their most extreme fever ever recorded in 2023, with marine heat waves so intense that some had less than a 0.4% chance of occurring naturally. Scientists say these are events that would typically happen only once every 276 years. Now, they suggest that these unprecedented ocean temperatures may represent an early signal that Earth’s climate system is approaching a tipping point.
A study published in Science reveals that 2023’s marine heat waves reached an activity level of 53.6 billion degrees Celsius per square kilometer. It’s a measurement so far beyond normal that it exceeded the historical average by more than three standard deviations.
Marine heat waves are extended periods when ocean temperatures spike well above normal, similar to how heat domes create deadly heat waves on land. But these oceanic events can persist for months or even years, fundamentally altering marine ecosystems and triggering cascading effects throughout the food chain.
The global scope was staggering: 96% of the world’s marine areas experienced these extreme temperatures, compared to the typical 73.7% coverage.
North Atlantic Breaks 525-Day Heat Record
The most extreme event occurred in the North Atlantic, where ocean temperatures remained dangerously elevated for 525 consecutive days. That’s the longest marine heat wave ever recorded in that region. Peak temperatures in some areas exceeded normal by more than 3 degrees Celsius, reaching levels that far surpass what most marine organisms can survive.
The Southwest Pacific experienced its own marathon heat wave lasting 410 days, with temperatures peaking in March 2023. Meanwhile, the North Pacific has been locked in an uninterrupted marine heat wave for four straight years.
Ocean Heat Drivers Vary by Region
Researchers from the Eastern Institute of Technology and Southern University of Science and Technology in China, led by Tianyun Dong and Zhenzhong Zeng, analyzed decades of satellite data and ocean measurements using computer models that track how heat moves through different ocean layers.
Different regions experienced marine heat waves for entirely different reasons. In the North Atlantic, a weakening of the Azores High, a massive high-pressure system that normally dominates the region, reduced cloud cover and allowed more solar radiation to penetrate the ocean surface.
The Southwest Pacific heat wave resulted from a strong high-pressure system that disrupted normal wind patterns while also reducing cloud cover and increasing solar heating. In contrast, the Tropical Eastern Pacific’s extreme temperatures were driven primarily by changes in ocean currents associated with El Niño conditions.
Marine Ecosystems Face Catastrophic Disruption
These temperature records represent catastrophic disruptions to marine life that ripple through entire ecosystems and economies. The 2023 heat waves triggered widespread coral bleaching events, placing intense thermal stress on these vital reef systems. Fish populations shifted dramatically as species fled toward cooler waters, decimating fishing industries in multiple regions.
Ocean warming contributes to about half of global sea level rise through a process where water expands as it heats up, posing severe flooding threats to coastal communities and low-lying island nations.
The Southwest Pacific heat wave likely contributed to the intensification of Cyclone Gabrielle, which devastated New Zealand, demonstrating how ocean warming directly fuels more powerful storms.
Scientists Warn of Approaching Climate Tipping Point
Perhaps most alarming, the researchers suggest that 2023’s marine heat waves may represent “an early signal of a tipping point in Earth’s climate system.” Climate tipping points are thresholds beyond which changes become self-reinforcing and potentially irreversible.
These ocean changes could destabilize polar ice sheets and weaken crucial ocean circulation patterns like the Atlantic Meridional Overturning Circulation, which helps regulate global climate. Such disruptions could fundamentally alter weather patterns worldwide, making extreme events even more common and severe.
The study found that 89% of Earth’s long-term energy imbalance (the excess heat trapped by greenhouse gases) gets stored in the oceans. The seas are essentially absorbing the brunt of climate change, but they’re reaching their limits.
Scientists emphasize the urgent need for enhanced ocean monitoring systems and improved predictive models to track these changes and provide early warnings. The 2023 marine heat waves serve as a stark reminder that the ocean, which covers 71% of Earth’s surface and regulates global climate, is experiencing rapid changes that could have long-lasting impacts on ecosystems and human societies.
Disclaimer: This article is based on findings from a peer-reviewed study. The interpretations and summaries are intended for general informational purposes and do not constitute scientific advice. All quotes are taken verbatim from the original paper unless otherwise noted.
Paper Summary
Methodology
Researchers analyzed marine heatwave data from 1982 to 2023 using satellite-derived sea surface temperature measurements and high-resolution ocean reanalysis data. They defined marine heatwaves as periods of at least five consecutive days when temperatures exceeded the 90th percentile of historical values. The team used the ECCO2 ocean reanalysis system and performed heat budget analysis to identify the physical processes driving these events across four key regions: North Atlantic, Southwest Pacific, North Pacific, and Tropical Eastern Pacific.
Results
The 2023 marine heatwaves reached unprecedented levels, with global activity totaling 53.6 billion °C days per square kilometer—more than three standard deviations above the 1982-2022 average. The events covered 96% of global marine areas and lasted an average of 120 days, compared to the historical average of 35.72 days. The North Atlantic experienced a 525-day heatwave with a 276-year return period, while the Southwest Pacific saw a 410-day event with a 141-year return period. Different regions showed distinct drivers: enhanced solar radiation and shallow mixed layers in the North Atlantic and North Pacific, reduced cloud cover and increased ocean currents in the Southwest Pacific, and ocean circulation changes in the Tropical Eastern Pacific.
Limitations
The study relies on reanalysis data and satellite observations, which may have uncertainties in remote ocean regions. The heat budget analysis, while comprehensive, may not capture all complex ocean processes. The return period calculations are based on historical data that may not fully represent future climate conditions. Additionally, the study focuses on four key regions and may not capture all global marine heatwave dynamics.
Funding and Disclosures
The research was supported by multiple Chinese institutions including Shenzhen Science and Technology Project, Guangdong Basic and Applied Basic Research Foundation, National Natural Science Foundation of China, China Meteorological Administration, Southern University of Science and Technology, and various Zhejiang Province and Ningbo Municipality programs. The authors declared no competing interests.
Publication Information
“Record-breaking 2023 marine heatwaves”
by Tianyun Dong, Zhenzhong Zeng, and colleagues was published in Science on July 24, 2025 (Volume 369, pages 369-374). The study was submitted on June 14, 2024, and accepted on May 21, 2025.
DOI: 10.1126/science.adr0910.
Those marine heat waves were devastating in 2023. Everyone I know died. It was so bad no one noticed the new viruses created in Wuhan.
“Self-serving Study Finds”
Clarity. /s
4 years left.
WE’RE ALL GOING TO DIE! AGAIN!!
Even “IF” this were true, there is NOTHING puny humans could do about it!
“Climate Change”, yup, climate changes everyday. Its called weather.
Here in California we’ve had one of the coolest summers in decades!
The climate of earth tends to stay within a relatively narrow band, largely because of the astounding power of a quantity of water molecules that fill the oceans and all surface waters, and a varying composition of the atmosphere. When very cold, the water molecules form into ice, and when very warm, into water vapor. In between, it remains largely in liquid form. The transition from solid to liquid involves the absorption of a great deal of heat, some 80 calories of heat per gram. To change one gram of liquid water to water vapor (steam) requires some 540 calories of heat, or conversely, the steam must give up that amount of heat energy to return to liquid state. Likewise, liquid water has to give up the 80 calories of heat energy per gram to form ice.
Water in all its forms is the great regulator of temperature of the air, soil and bodies of water. Runaway “tipping point” changes are not possible over the short term. And the presence or absence of carbon dioxide has not a damned thing to do with
the heat transfer capacity of the water molecule.
I wish they would just stop with this. What is the point of claiming we have reached a “climate tipping point”? If true, there is little to be done. If false, why is this published? The author and publisher should both be flogged.
“...climate changes everyday. Its called weather....”
I don’t know how many times I have said that same thing over the years.....
“...climate changes everyday. Its called weather....”
I don’t know how many times I have said that same thing over the years.....
What we will see from this is an increase in atmospheric CO2 as the oceans release CO2 dissolved in the colder waters.
The question will be, will “science” report this correctly...
Heck, who believes anything published by "scientists" who are increasingly publishing crap.
Every time a can of soda is opened CO2 IS RELEASED............
Will the “tipping point” hit Guam first?
Asking for Congressman/Guitarist Hank J.
Everytime you or I breathe out, CO2 is released!
“...may represent an early warning sign...”
Definitely time to panic.
So if this is coming out of China, why is China still building coal burning power plants if globull warming is caused by CO2?
Algore’s climate clock expired so we all dead now , burned to crisps
It’s the Glacial termination phase.
Last time it happened was 2.5 mya. It’s the same with today.
-Methane levels spike. -Check
-CO2 levels spike. -Check
-Oceans rise (120’ feet to go). -In progress
The actual Tipping Point is when the warmed planet begins storing more greenhouse gases then it releases.
OH NOES! We’re DOOOOOOMED!
Ya know... these climate clowns were telling us we’d be in an ice age by 1976, then the sun would burn off the ozone layer and we’d all have to wear big hats and sunscreen by the year 2000... then some other thing... and then some other thing after that...
I’m STILL waiting for that danged ice age...
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.