Physical Address
23,24,25 & 26, 2nd Floor, Software Technology Park India, Opp: Garware Stadium,MIDC, Chikalthana, Aurangabad, Maharashtra – 431001 India
The warming of the world’s oceans is doing more than harming marine life and raising sea levels. A new study now shows that hotter oceans are also playing a major role in driving heatwaves on land. Researchers found that warming coastal waters are closely linked to the growing spread and intensity of humid heatwaves across many regions of the world. The findings add to a growing body of evidence showing that climate extremes do not occur in isolation. Instead, rising sea surface temperatures are helping shape dangerous weather conditions over land, with serious implications for public health, agriculture and disaster preparedness in a warming world.
Oceans are increasingly shaping the heat on land
The study found that coastal ocean warming is strongly associated with the rise of large-scale humid heatwaves over nearby land areas. Researchers analysed climate data from 1982 to 2023 and found that warming oceans were linked to around 50% of the upward trend in humid heatwave frequency and about 64% of the increase in their spatial spread across hotspot regions. This means that as sea surface temperatures rise, heatwaves on land are becoming not just more common, but also more widespread.
The connection was especially strong in the tropics, where many of the world’s most heat-vulnerable regions are located. According to the study, tropical oceans appear to play a particularly important role because they influence how moisture and heat move through the atmosphere. This makes coastal and nearby inland regions more prone to prolonged spells of dangerous humid heat, where high temperatures combine with moisture to make conditions harder for the human body to tolerate.
Indian Ocean warming is emerging as a major concern
The study highlighted the Indian Ocean as one of the key ocean regions influencing heat extremes over land. Researchers noted that warming in this basin is helping drive widespread heatwaves across South Asia and West Asia, regions that are already experiencing more frequent and intense heat events. This is particularly significant for countries like India, where heatwaves are becoming longer, arriving earlier and affecting larger populations each year.
Scientists say the process works through atmospheric linkages. As ocean surfaces warm, they release more moisture and heat into the air above them. This can alter atmospheric circulation and strengthen the conditions that allow humid heatwaves to build over land. In mid to high latitude regions, the study found that atmospheric wave patterns also help connect warmer oceans with rising land heat. But in tropical regions, the ocean itself appears to be a stronger driver of what people experience on the ground.
Why this matters for heat risk and planning
Humid heatwaves are among the most dangerous forms of extreme heat because they reduce the body’s ability to cool itself through sweating. That makes them especially risky for outdoor workers, older people, children and those without access to cooling. If warming oceans are increasing both the frequency and spread of such events, it means many countries may need to rethink how they prepare for future heat risks.
The findings also suggest that sea surface temperature could serve as an early warning signal for land-based heat extremes. Researchers say coastal ocean warming may act as a useful precursor for forecasting large-scale humid heatwaves before they fully develop. That could improve preparedness in sectors such as health, farming and urban planning, especially in tropical countries where exposure is high, and adaptation remains uneven. As oceans continue to absorb most of the excess heat trapped by greenhouse gases, their role in shaping dangerous conditions on land is becoming harder to ignore.
References:
https://www.nature.com/articles/s41561-026-01952-z
https://www.downtoearth.org.in/climate-change/warming-oceans-linked-to-rise-in-land-heatwaves-study
Banner image: Photo by Michael Krahn on Unsplash
Sections of this article may have been developed with the assistance of artificial intelligence tools to support research, drafting and language refinement. All information has been reviewed, edited and verified by the author/editor to ensure accuracy, context and editorial integrity. The responsibility for the final content, interpretations and conclusions rests solely with the publisher.
