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Saturday, Dec 13, 2025
Outside the box.
Marine Heatwave Engulfs Ocean Area Five Times the Size of Australia
A World Meteorological Organization report reveals unprecedented ocean temperatures and their global impacts.
In 2024, nearly 40 million square kilometers of ocean around Southeast Asia and the Pacific experienced a marine heatwave, covering an area five times larger than Australia, according to a recent report from the World Meteorological Organization (WMO).
The report attributes this record heat, both in the ocean and on land, primarily to the ongoing climate crisis, highlighting its correlation with a series of severe weather incidents.
The affected region recorded temperatures 0.48 degrees Celsius above the average from 1991 to 2020. Satellite data indicated that sea levels were rising at a rate of nearly 4 millimeters per year, outpacing the global average rise of 3.5 millimeters annually.
Prof. Celeste Saulo, WMO Secretary General, emphasized the long-term detrimental effects of ocean heat and acidification on marine ecosystems and economies.
She referred to the issue of sea-level rise as an existential threat for many island nations, noting the urgent need for effective climate action.
The report outlines a number of extreme weather events occurring alongside the marine heatwave:
- In January and February, the Philippines experienced extreme rainfall, leading to floods and landslides that resulted in at least 93 fatalities.
- Australia faced an early-season heatwave, marked by record-breaking temperatures across much of the central regions in August.
- Major flooding in Singapore and Malaysia displaced approximately 137,000 people and caused six deaths.
- In March, flash flooding struck the Indonesian island of Sumatra, and northern Australia also dealt with significant flooding early in 2024.
- The report cautioned that rapid glacier loss was observed in western New Guinea, Indonesia, with total ice loss predicted as early as 2026.
- The Philippines was impacted by 12 tropical cyclones, doubling the typical average, with damage estimates reaching $430 million.
- Australia’s snow season concluded unusually early.
Ben Churchill, WMO director for the region, noted that these findings underline the importance of intensified climate action, stating that the report reflects occurrences unprecedented in recorded history.
In the first half of 2024, sea surface temperatures in almost 40 million square kilometers of the region saw categories ranging from moderate to strong heatwaves.
This marine heatwave contributed to the fifth mass coral bleaching event in Australia's Great Barrier Reef since 2016, leading to extensive coral mortality.
Assoc.
Prof. Alex Sen Gupta, a climate scientist at the University of New South Wales, described the event as particularly remarkable, indicating a significant increase in global ocean temperatures beginning in 2023. He highlighted that the heatwave imposes stress on various marine organisms, which have specific temperature thresholds that, if exceeded, can lead to failure or death.
The report attributes this record heat, both in the ocean and on land, primarily to the ongoing climate crisis, highlighting its correlation with a series of severe weather incidents.
The affected region recorded temperatures 0.48 degrees Celsius above the average from 1991 to 2020. Satellite data indicated that sea levels were rising at a rate of nearly 4 millimeters per year, outpacing the global average rise of 3.5 millimeters annually.
Prof. Celeste Saulo, WMO Secretary General, emphasized the long-term detrimental effects of ocean heat and acidification on marine ecosystems and economies.
She referred to the issue of sea-level rise as an existential threat for many island nations, noting the urgent need for effective climate action.
The report outlines a number of extreme weather events occurring alongside the marine heatwave:
- In January and February, the Philippines experienced extreme rainfall, leading to floods and landslides that resulted in at least 93 fatalities.
- Australia faced an early-season heatwave, marked by record-breaking temperatures across much of the central regions in August.
- Major flooding in Singapore and Malaysia displaced approximately 137,000 people and caused six deaths.
- In March, flash flooding struck the Indonesian island of Sumatra, and northern Australia also dealt with significant flooding early in 2024.
- The report cautioned that rapid glacier loss was observed in western New Guinea, Indonesia, with total ice loss predicted as early as 2026.
- The Philippines was impacted by 12 tropical cyclones, doubling the typical average, with damage estimates reaching $430 million.
- Australia’s snow season concluded unusually early.
Ben Churchill, WMO director for the region, noted that these findings underline the importance of intensified climate action, stating that the report reflects occurrences unprecedented in recorded history.
In the first half of 2024, sea surface temperatures in almost 40 million square kilometers of the region saw categories ranging from moderate to strong heatwaves.
This marine heatwave contributed to the fifth mass coral bleaching event in Australia's Great Barrier Reef since 2016, leading to extensive coral mortality.
Assoc.
Prof. Alex Sen Gupta, a climate scientist at the University of New South Wales, described the event as particularly remarkable, indicating a significant increase in global ocean temperatures beginning in 2023. He highlighted that the heatwave imposes stress on various marine organisms, which have specific temperature thresholds that, if exceeded, can lead to failure or death.
