By Arden Dier , Newser.AI .  Excerpt: The massive marine heat wave, formed as a North Pacific hot spot merged with warming tied to a developing super El Niño along the equator, covers about 13.5% of Earth's surface, stretching from the Philippines to Peru and toward Hawaii and California...the Washington Post reports. Forecasters say the heat is already helping fuel Super Typhoon Bavi in the western Pacific and could help set up a strong heat dome over the western US in mid-July, heightening fire risks from Arizona to Colorado. As the ocean absorbs heat, the water expands, with implications for global sea levels. ...sea levels this winter could run 6 inches to 2 feet above normal—with storms pushing that surge to 2 to 3 feet higher, raising the odds of disruptive coastal flooding, the Post reports. ...Globally, marine heat waves now cover more than 37% of the ocean, triple the share seen in the late 1980s....  Full article at https://www.newser.com/story/392288/pacific-ocean...

By Sarah Derouin , Eos/AGU.  Excerpt: Researchers found the unprecedented 2023 East Asian marine heat wave increased land temperatures and humidity by up to 50%....  Full article at https://eos.org/research-spotlights/marine-heat-waves-can-exacerbate-heat-and-humidity-over-land . 

By Robert Sanders , UC Berkeley News.  Excerpt: Sea urchins are a key but often destructive part of the kelp forest ecosystem along the Pacific Coast, and in boom years can often turn these forests into barrens devoid of marine life. But it remains a mystery what causes urchin boom and bust cycles and how sea urchins are affected by increasingly common marine heat waves. A new study by marine biologists at the University of California, Berkeley, now suggests that sea urchin populations along the Pacific Coast are more susceptible to heat waves than once thought, because the animals ramp down reproduction at temperatures substantially below levels that kill them. ...The study,  published last week  in the journal  Communications Biology , a  Nature  journal, was conducted in cooperation with the Hakai Institute in British Columbia, Canada, and UC Davis’s Bodega Marine Laboratory in California....  Full article at https://news.berkeley.edu/2025/11/14/ev...

By Grace van Deelen , Eos/AGU.  Excerpt: A yearly analysis of climate change’s progress and effects shows a “planet on the brink” of ecological breakdown and widespread crisis and suggests that only rapid climate mitigation can avoid the worst consequences. ...The sixth annual report, published in  BioScience ,  analyzes global data on Earth’s atmosphere, oceans, energy, ecosystems, food systems, and more. Researchers identified our planet’s so-called vital signs, including ocean temperature, surface temperature, sea ice extent, and carbon pollution. Of the 34 vital signs, 22 were at record levels, indicating a highly stressed Earth system. For example, 2024 surpassed 2023 as the hottest year on record.  Ocean heat  and  wildfire -related tree cover loss are both at all-time highs. Deadly weather disasters surged in 2024 and 2025, with floods, wildfires, and typhoons killing  hundreds in the U.S. alone . Atmospheric warming is showing signs of acc...

By Science Advisor.  Excerpt: Researchers have declared  southern Florida’s  Acropora  coral colonies functionally extinct . The death knell for two reef-building species, elkhorn and staghorn, was the 2023 marine heatwave that brought temperatures above 31°C for almost 6 weeks. The event was the ninth mass coral mortality event for the region since 1987. “ This ecosystem is forever transformed ,” lead author Ross Cunning told  Nature . Conservation for these species “needs to fundamentally change.” Acropora  have made Florida and the Caribbean their home for the past 250,000 to 500,000 years. During the heatwave, they bleached in 98% to 100% of their southern Florida range, a process whereby the corals lose the symbiotic algae that feed them and give them color. Previously, scientists had attempted to reintroduce the corals in areas where they had declined. But with the reintroduced organisms now dead, the authors say that efforts must turn to breeding mor...

By Warren Cornwall , Science.  Excerpt: ...the recent fate of snow crabs in much of the Bering Sea. An unprecedented underwater heat wave there in 2018 and ’19 set off a chain reaction that led to the disappearance of an estimated 47 billion crabs, one of the largest marine die-offs ever documented. Suddenly, a $150 million fishery mythologized in the  Deadliest Catch  reality TV show found itself with no catch at all. State regulators for the first time banned Bering Sea snow crab fishing in 2023 and ’24, and the U.S. government declared a federal fishery disaster. The fishery reopened this year. But crabbing boats were only allowed to haul in a tiny fraction of what they had caught previously. The collapse “has had massive impacts,” says Scott Goodman, a fisheries biologist and executive director of the Bering Sea Fisheries Research Foundation, which is funded by the crab industry. ...In the early months of 2018 and again in 2019, however, the winds reversed, blowing fr...

By Andrew Freedman , CNN.  Excerpt: A record-breaking and astonishingly expansive  marine heat wave  is underway in the Pacific Ocean, stretching about 5,000 miles from the water around Japan to the West Coast of the United States. The abnormally warm “blob” of ocean water, which is getting a significant boost from human-caused global warming, is affecting the weather on land and could have ripple effects on marine life. ...The sea surface temperature difference from average across the entire North Pacific  smashed an all-time record  for the month of August, with reliable data stretching back to the late 19th century. What worries scientists is the repetitive nature of these events. As climate change causes more heat to be stored in the oceans, ocean temperatures are reaching new heights that could lead to more significant impacts from these heat waves like this. ...Past Northeast Pacific Ocean blobs led to a  historic die-off of seabirds  in coastal ...

By Tianyun Dong et al, Science.  Editor’s summary: Ocean surface temperatures vary from year to year, experiencing heat waves like those felt on land, but 2023 saw an extraordinarily large increase in marine heat waves with no recent analog. Dong  et al . report that 2023 set new records in the duration, extent, and intensity of these events by as much as three standard deviations above the historical average of the past four decades. The increasing trends in marine heat waves present intensifying dangers to ecological, social, and economic systems. —Jesse Smith.  Full article at https://www.science.org/doi/10.1126/science.adr0910 .

By Austyn Gaffney , The New York Times.  Excerpt: Earth is missing a lot of sea ice this year. Enough to cover the entire United States east of the Mississippi. That was announced by researchers at NASA and the National Snow and Ice Data Center on Thursday, who said the amount of sea ice on the planet had reached the  lowest level ever recorded in March . The record comes days after the World Meteorological Organization reported that  the past 10 years have been the 10 hottest on record , with 2024 the hottest year. The global rise in temperatures is tied to increasing concentrations of greenhouse gases, largely caused by the burning of fossil fuels....  Full article at https://www.nytimes.com/2025/03/27/climate/global-sea-ice-record-low.html . 

By Robert F. Service , Science.  Excerpt: The carbon dioxide (CO 2 ) spewing from human activities is not only changing Earth’s atmosphere, it’s also rapidly acidifying the planet’s oceans. In 50 years, that acidification could reduce the oceans’ ability to absorb CO 2  by 10% as it takes a toll on phytoplankton, microscopic single-cell organisms that feed on the gas through the process of photosynthesis, a new study suggests. Reported this week in the Proceedings of the National Academy of Sciences,  the effect could in turn cause atmospheric CO 2  to build up faster  and accelerate warming of the global climate....  Full article at https://www.science.org/content/article/more-carbon-dioxide-oceans-could-harm-carbon-eating-microbes-speed-climate-change .

By Anupama Chandrasekaran , Eos/AGU.  Excerpt: When an intense marine heat wave sent ocean temperatures soaring in 2023 and 2024, coral reefs around the world bleached. New research on the Great Barrier Reef’s One Tree Island shows that more than 50% of surveyed coral colonies that bleached died of heat stress and starvation. And even heat-resistant corals weren’t immune. When corals are stressed by warm water, they can lose the algae that live in their tissues. This process turns the coral white, earning it the name “ coral bleaching .” Sometimes corals can recover, but if the stress is too intense, they die and eventually crumble into rubble and sand. “What we noticed in more recent times, when it gets really hot, they often die before they even fully bleach,” said marine biologist  Maria Byrne  at the University of Sydney....  Full article at https://eos.org/articles/great-barrier-reef-corals-hit-hard-by-marine-heat-wave .

By Catrin Einhorn , The New York Times.  Excerpt: The first evidence was the feathered bodies washing up on Alaskan beaches. They were common murres, sleek black-and-white seabirds that typically spend months at a time away from land. But in 2015 and 2016, officials tallied 62,000 emaciated corpses from California to Alaska. Since then, scientists have been piecing together what happened to the birds, along with other species in the northeast Pacific that suddenly died or disappeared. It became clear that the culprit was an record-breaking marine heat wave, a mass of warm water that would come to be known as the Blob. New findings on its effect on murres,  published on Thursday in the journal Science , are a stark sign of the perils facing ecosystems in a warming world....  Full article at https://www.nytimes.com/2024/12/12/climate/alaska-common-murre-birds-ocean-heat.html . 

By Roberto González , Eos/AGU.  Excerpt: Rapid intensification of hurricanes is 50% more likely to occur during marine heat waves in the Gulf of Mexico and northwestern Caribbean Sea ...according to a  study  published in August in  Communications Earth and Environment . These types of hurricanes are more dangerous as they make landfall because their intensity is harder to predict....  Full article at https://eos.org/articles/marine-heat-waves-make-tropical-storm-intensification-more-likely .  See also other Eos articles on heat waves - https://eos.org/tag/heat-waves . 

By Carolyn Gramling , Science News.  Excerpt: One of the widest hurricanes on record slammed into Florida’s Gulf Coast on September 26 as a powerful Category 4 storm, inundating Florida’s coast with meters-high storm surge and sending tropical storm–force winds as far as 500 kilometers from its eye. ...Just three days earlier, it was a disorganized cluster of thunderstorms off the eastern coast of Mexico’s Yucatán Peninsula. A mere “tropical disturbance,” it was dubbed PTC9 for tracking purposes. ...Within just 60 hours...PTC9 would intensify...from winds less than 35 knots (about 65 kilometers per hour) to hurricane-force winds of at least 100 knots (185 kilometers per hour). It was the fastest predicted spin-up from disturbance to major hurricane in the NHC’s history. ...Rapid intensification is becoming a new normal for hurricanes. NHC  defines rapid intensification  as when a storm’s maximum sustained winds jump by at least 56 kph (35 miles per hour) in less than a da...

By Raymond Zhong , The New York Times.  Excerpt: Tropical Storm Debby’s time back at sea on Wednesday was helping it recharge somewhat before it was expected to drift back onto the South Carolina shore overnight, according to the National Hurricane Center. The ocean provides storms like Debby with two key ingredients they need to pack a wallop: warm water and moist air. There’s plenty of moisture in the air off the Southeastern coast right now because both the seawater and the air above it have been unusually warm. The warmer the water, the more it evaporates, sending moisture into the air. And the warmer this air is, the more moisture it can take up. Bottom line: Warm seas and warm air help make for stronger storms. ...Worldwide, the amount of water vapor in the atmosphere has increased by about 2 percent per decade since the early 1990s, according to  a study published  in May....  Full article at https://www.nytimes.com/2024/08/07/climate/warm-air-oceans-power-sto...

By Sarah Stanley , Eos/AGU.  Excerpt: Marine life ...depends on the right combination of water temperature, acidity, and oxygen levels, so creatures such as fish and plankton can be  hard hit  by large regional fluctuations in any of these parameters. When two, or even all three, are off-kilter, the environment can become uninhabitable for many species. Because climate change has generally been  heating the ocean ,  boosting its acidity , and  lowering its oxygen levels , concerns over these regional multithreat events—known as column-compound extremes—are growing. Now,  Wong et al.  report that since the early 1960s, column-compound extremes have been intensifying: growing larger in volume, lasting longer, and occurring more often. ...The analysis suggests that triple column-compound extremes—events involving the convergence of extreme temperatures, high acidity, and low oxygen levels—occupied 39 times more ocean volume, lasted 3 times longer, an...

By WARREN CORNWALL , Science.  Excerpt: Starting in late 2013, the first in a handful of  record-shattering heat waves  struck the north Pacific Ocean near Alaska. Temperatures in these warm “blobs,” which have occurred four times in the past decade, sometimes reach more than 2°C above normal. ...Research has implicated climate change, which can supercharge natural fluctuations in ocean heat. But now, scientists are pointing to another surprising contributor: China’s success in stemming air pollution. A steep decline in aerosols—tiny airborne particles such as sulfates—emitted by Chinese factories and power plants in the 2010s appears to have amplified a string of extreme heat waves on the other side of the Pacific,  driving up to 30% of the temperature increase during these heat waves , scientists report today in the Proceedings of the National Academy of Sciences. ...Aerosols can act like tiny mirrors, reflecting sunlight back into space and reducing the ...

https://www.nytimes.com/2024/04/10/climate/ocean-heat-records.html By Delger Erdenesanaa , The New York Times.  Excerpt: The ocean has now broken temperature records every day for more than a year. And so far, 2024 has continued 2023’s trend of beating previous records by wide margins.... 

https://edition.cnn.com/2024/03/07/australia/mass-coral-bleaching-event-great-barrier-reef-intl-hnk-scn/index.html By Helen Regan , CNN.  Excerpt: Australia’s Great Barrier Reef is suffering another  mass bleaching event , the reef’s managers confirmed Friday, the result of soaring ocean temperatures caused by the global climate crisis and amplified by  El Niño . This is the seventh mass bleaching event to hit the vast, ecologically important but fragile site and the fifth in only eight years.... 

https://www.science.org/content/article/after-mass-coral-die-off-florida-scientists-rethink-plan-to-save-ailing-reefs By WARREN CORNWALL , Science.  Excerpt: Four years ago, the U.S. National Oceanic and Atmospheric Administration (NOAA) unveiled a $100 million coral moonshot. Over 2 decades, nearly half a million hand-reared coral colonies would be planted on seven ailing reefs in southern Florida, in a bid to revive them. ...Today, the project looks as ailing as the coral it was meant to save. A record-breaking underwater heat wave that swept the Caribbean and southern Florida in 2023 killed most of the transplanted colonies....