A global study, published in the second week of June in an international journal and concurrently showcased during the ongoing global climate meeting at Bonn, pointed out that marine heatwaves, among all the major indicators of global climate change globally, have risen most sharply over the last five years; since the publication of the last UN report about five years back.
The report, published in the highly rated international interdisciplinary journal Earth System Science Data and authored by around 70 frontline global scientists across 17 countries including India, led by Leeds University, found that though all 11 major global climate change indicators increased during the timeline, marine heatwaves led the race with daily temperature increasing by 61.1 percent, followed by energy imbalance with 41.8 percent.
Several scientists linked to the Intergovernmental Panel for Climate Change (IPCC) over the years have participated in the study. Intergovernmental Panel for Climate Change (IPCC), an UN scientific body with nearly 3000 scientists, published its last set of reports, known as AR (assessment report) 6, in between 2021-2023.
“The (current) study aims to fill potential information gaps between IPCC reports, providing decision makers with timely and scientific information on policy-relevant global climate indicators such as levels of greenhouse gas emissions, human-caused warming, and temperature and climate extremes,” reads the report adding that the methodologies closely follow those in the IPCC Sixth Assessment Report (AR6), whilst also tracking how they are evolving between successive IPCC report cycles.
According to data, India is one of the highly affected countries regarding marine heatwaves apart from showing other impacts.
All indicators upward-bound
“Human activities pushed global warming to 1.37°C in 2025 (third warmest year ever) and its level is projected to surpass 1.5°C in about four years. Crucially, the rate at which heat is accumulating in the Earth system suggests high levels of future warming,” points out the report adding that “… Relative to pre-industrial times, over the 2016-2025 decade, land temperatures increased by 1.81°C, and ocean temperatures by 1.03°C.”
The pre-industrial temperature is considered as the benchmark of understanding global warming linked to climate change as it is assumed that the human inflicted warming had only started through industrial revolution occurring between 1850 to 1900.
The report, a copy of which is with this correspondent, shows that all 11 key indicators of global climate change, considered under the study, have increased since the publication of the AR 6 report.
Followed by table topper marine heatwaves followed by energy imbalance by some distance, maximum daily temperature with 23.9 percent and human induced warming with 15.9 percent are the next two in climate change ladder. The green house gas overall has risen by 2.1 percent, with all major constituents of green house gas carbon di oxide, methane and nitrous oxides rising by 3.8. 3.8 and 2.2 percentages respectively.
“Clearly all the data are showing that the global climate is going opposite to where they should be, and the politicians are to blame for the suicidal trend,” said one climate expert at Bonn global climate meet.
Human (in)action to blame
Professor Piers Forster, director of the Priestley Centre for Climate Futures at the University of Leeds and lead author of the report, explained to this correspondent at Bonn that “ … Earth’s energy imbalance, a key indicator that measures how fast heat is accumulating in the climate system and provides a crucial measure of the pace of climate change, is now at a record high, doubling in recent decades,” adding that “ without human influence, it should be close to zero, but it has been growing since the 1970s”. The latest report finds that global greenhouse gas (GHG) emissions are now at an all-time high, reaching 56.8 billion tonnes of carbon dioxide and equivalent emissions (CO2e), mainly from the burning of fossil fuels.
“Our study demonstrates that nearly all of the warming over the last decade is driven by human activities. The impacts on livelihoods and ecosystems are already being felt worldwide, and will accelerate as temperatures continue to increase,” said Samantha Burgess, an weather expert at European Centre for Medium-Range Weather Forecasts (ECMWF), and part of the study.
The rate of human-induced warming remains at the all-time high of 0.27°C per around decade, driven primarily by record-high greenhouse gas levels, combined with the continued fall in sulphur dioxide (SO2) emissions partly resulting from measures to tackle air pollution.
“We expect to share the critical findings with the decision makers for enabling them to take appropriate actions in the coming COP meeting scheduled at Turkey,“ shared an expert.
Indian ocean marine heatwave rising
“Our research shows that the Indian Ocean is moving toward a near-permanent marine heatwave state by the 2050s,” Roxi Mathew Koll, a scientist at the Indian Institute of Tropical Meteorology (IITM) and a climate expert, recently told this correspondent.
A 2024 publication of Roxi Koll in ScienceDirect journal points out “… The tropical Indian Ocean has undergone basin-wide surface warming since the start of the 20th century, with a rate of 0.12°C per decade between 1950 and 2020, which is the fastest among the tropical basins”.
“The warming penetrates the deep ocean, with an increase in the ocean heat content from the surface until 2000 m … Climate models … project that in response to mid-to-high greenhouse gas emissions the Indian Ocean will very likely experience surface warming of 1.4–3°C between 2020 and 2100, at a rate of 0.17–0.38°C per decade,” it further finds.
Based on the findings, the study concludes that the “… Marine heatwaves are projected to increase from 20 days per year (during 1970–2000) to 220–250 days per year, pushing the tropical Indian Ocean into a basin-wide near-permanent heatwave state by the end of the 21st century.”
With input from Biswendu Bhattacharjee