Antarctic sea ice levels have been at record lows for the last three years, a global report shows.
The World Meteorological Organisation’s State of the Global Climate 2024 report also highlights three years of record glacier loss, record air and ocean temperatures, the highest atmospheric CO₂ levels in 800,000 years, and a doubling of the rate of sea level rise since satellite measurements began.
The Science Media Centre asked third-party experts to comment. Comments gathered by the AusSMC are available on Scimex.
Dr James Renwick, Professor of Physical Geography, Victoria University of Wellington, comments:
“This latest report from the World Meteorological Organization is more bad news about climate change. It tells a now-familiar story, record warming, record ocean heat content, melting ice and accelerating sea level rise, and many extreme weather events globally. All extremely worrying, yet apparently of little concern to the world’s policy-makers, since there is no sign the world is living up to the Paris Agreement to limit warming to 1.5-2°C. Greenhouse gas emissions that drive climate change just keep increasing, regardless of the bad news. Perhaps our busy lifestyles and the churn of the 24-hour news cycle means climate change just doesn’t have time to register?
“But let’s pause for a moment. This latest report is saying global temperatures are higher than they have been for at least 175 years – and yet 2024 will be one of the coldest years this century, as we keep adding warming gases to the atmosphere. Sea level rise is speeding up and will be irreversible for hundreds of years – as will glacier ice melt. Reversing ice sheet melt would take thousands of years. Our busy day-to-day activities have consequences that will last for centuries, even millennia. As sea levels rise, we are changing global coastlines and the map of the world essentially for ever. I would hope that information causes policy-makers everywhere to lift their eyes, to take notice and to take action.
“For many years, one hold-out in this picture has been Antarctic sea ice extent. It kept increasing through the 1990s and 2000s, even though the world was warming. But no longer. The warming of the oceans has finally started to materialise over the surface of the southern oceans and sea ice is paying the price. The last three years show the three lowest Antarctic ice minima in the satellite record. There will be plenty of ups and downs over coming years, but the trend will very likely be down from here. Scientists in the New Zealand Antarctic Science Platform, and their collaborators from around the world, are pushing hard to establish the trajectory from here, and the consequences for Antarctic ecosystems, for New Zealand weather & climate, and for the global climate system.”
Conflict of interest statement: “I receive funding from MBIE and other agencies to study climate change. I was an author on the past three Assessment Reports of the Intergovernmental Panel on Climate Change. I was a Commissioner with the New Zealand Climate Change Commission.”
Dr Alexandra Gossart, Research Fellow – Regional Climate Modelling, Antarctic Research Centre, Victoria University of Wellington, comments:
“You don’t need to be a climate scientist to understand the latest WMO State of the Climate report—it’s plain for all to see that climate indicators are deteriorating more frequently and with greater intensity over recent years than ever.
“While the Antarctic climate may seem distant from daily life in Aotearoa, changes there are happening at an accelerating pace with growing implications for us. A warming atmosphere and ocean, along with declining sea ice, allow more heat to reach the ice sheet, contributing to ice mass loss and, ultimately, global sea level rise.
“Although there might have been moments of relative stability in the past, recent years have shown a steady increase in climate records being broken. A young person coming of age today has only ever known a world with rising CO₂ levels, global warming air and oceans, increasing sea levels, shrinking ice sheets and glaciers, and declining sea ice cover.
“While uncertainties remain, particularly around feedback processes and complex climate interactions, one thing is certain—things are changing, and at an increasing pace. However, I choose to believe that the future is not set in stone. The choices we make today—through science, policy, and collective action—can hopefully slow these trends and reduce their impact.”
Conflict of interest statement: No conflicts of interest.
Dr Melissa Bowen, Associate Professor of Oceanography, School of Environment, University of Auckland, comments:
“There are no surprises here.
“The ocean has been soaking up the extra energy on the planet for a long time. We need to prepare now for the impacts of a warmer ocean. Where is heat coming back to the surface? What changes will it make to our extreme weather?
“The ocean is not absorbing heat uniformly. Some places in the ocean, such as the region around New Zealand are picking up more heat and storing it at different depths. How the ocean circulates determines where the heat goes—how fast it will return to the surface, how much it will change the sea surface temperature—and how it will affect the atmosphere.
“The highs and lows in Antarctic sea ice are following a path suggested in studies ten years ago. Ten years ago, strengthening westerly winds in the Southern Hemisphere pulled more cold water northward and Antarctic sea ice expanded with it. Now we can see warmer water below the surface, likely contributing to the extra sea ice melt. However it’s unclear how much that warming is due to the increased winds pulling warmer water upwards, as suggested in the early studies, and how much is due to a warmer atmosphere heating the ocean from above.”
Conflicts of interest statement: No conflicts of interest.
Dr Lauren Vargo, Research Fellow, Antarctic Research Centre, Victoria University of Wellington, comments:
“While sobering, this updated report isn’t new information for those of us who study climate change. The section on glacier mass loss states that glaciers globally have lost more volume over the past three years compared to any other three-year period since measurements began.
“This is concerning because glacier melt impacts global sea level rise, water resources, hazards, ecosystems, and cultural connection to place. New Zealand glaciers are no exception—a recent report found that glaciers in Aotearoa lost ~30% of their volume from 2000–2023.
“Using measurements of glacier change and glacier models, we know that glacier mass loss is being made more likely and more severe with human-caused climate change.
“Glacier models also show us what the future might look like: if warming reaches 5°C (above pre-industrial levels), it’s likely that we will lose almost all the glaciers that exist today. However, if we can reduce greenhouse gas emissions and limit warming to 2°C, many of the Southern Alps glaciers will persist.”
Conflict of interest statement: “I have received funding from the Marsden Fund to study how glaciers and climate change.”
Professor Nick Golledge, Antarctic Research Centre, Victoria University of Wellington, comments:
“What is particularly alarming is the acceleration in several of the key indicators presented in this report. For example, in line with the acceleration in global mean temperature from 1970 onwards, the last two decades are showing an increasingly clear acceleration in the rate of ice loss from global glaciers, and from the ice sheets in Greenland and Antarctica. Together, these are the systems that are contributing to the recent doubling in the rate of global sea level rise.
“These data show unequivocally that rising carbon dioxide concentrations in the atmosphere have led to a worldwide warming of the climate that is now clearly driving ice melt and sea level rise. These findings are entirely consistent with the headline statements from the 2021 IPCC Sixth Assessment report, and underline the sensitivity of our climate to atmospheric pollution.
“The most concerning aspect of this is that simply stabilising greenhouse gas emissions will not be sufficient to limit global mean temperatures to the 1.5 or even 2°C ‘safe’ limit agreed in the 2015 Paris Accord. Stringent mitigation is now critically important if we are to retain a habitable climate for our planet.”
Conflicts of interest: None declared.
Dr Dan Lowry, Climate Scientist, GNS Science, comments:
“The State of the Global Climate 2024 report shows that ice sheets and glaciers are in a state of rapid decline, with global glacier mass loss accelerating at an alarming rate. Data from 2021 to 2024 shows the most negative three-year glacier mass balance on record, with 7 of the 10 largest negative balances since 1950 occurring since 2016. Ice loss from glaciers as well as the Greenland and Antarctic ice sheets is significantly contributing to rising sea levels, accounting for approximately 44% of the total sea-level rise between 1993 and 2018.
“The data confirms an unequivocal trend: the planet’s frozen reservoirs are melting faster than ever, with profound consequences for global climate stability. This is especially concerning as the report also confirms we are inching closer to exceeding global mean temperature of 1.5°C above pre-industrial, a threshold in the climate system where we expect irreversible change in glaciers and ice sheets to occur. As glaciers and ice sheets continue to diminish, the cascading impacts—ranging from disrupted ocean currents to increased coastal flooding—will intensify. Urgent action is needed to mitigate greenhouse gas emissions and enhance resilience in vulnerable coastal communities.”
Conflict of interest statement: No conflicts of interest.
Associate Professor Inga Smith, Department of Physics, University of Otago and Co-Director of He Kaupapa Hononga: Otago’s Climate Change Research Network, comments:
“The WMO “State of the Global Climate 2024” report notes that the 2024 Antarctic sea-ice extent annual minimum (in late summer) and maximum (in late winter) were the second lowest minimum and the second lowest maximum since satellite observations began in 1979. The report also notes that 2022, 2023, and 2024 had the three lowest Antarctic ice extents.
“Antarctic sea-ice extent had been relatively stable between 1979 and 2016, so the recent changes have alarmed many people. The record lows in winter sea-ice extent, particularly 2023 and 2024 have caused great concern in the sea ice science community, because those changes were not gradual. The abrupt drops in sea-ice extent at a time when the sea ice should still be growing in winter has been suggested might be a regime shift.
“The shift may be due to warmer waters, as well as changes in wind patterns and other factors. The consequences of less sea ice in the Antarctic winter have been reported to include increased storminess in the Southern Ocean, which is already very stormy. Aotearoa New Zealand is a country directly impacted by what happens in the Southern Ocean and Antarctica, so the sea ice issues and consequences raised in this report should be very concerning to all New Zealanders.”
Conflict of interest statement: No conflicts of interest.
Dr Andrew Pauling, Research Fellow, Department of Physics, University of Otago, comments:
“The recent behaviour of Antarctic sea ice has continued to be concerning. Prior to 2015, Antarctic sea ice extent was increasing slightly over time, but it has declined rapidly since. Its behaviour has been remarkably different to that of Arctic sea ice, which has declined steadily over the entire satellite era (1979-present).
“It has been argued that the recent record minimum in 2023 represents a “regime shift” in Antarctic sea ice driven by ocean warming around the continent. There is also evidence that there has been a “structural change” to the Antarctic sea ice system, indicating that we can no longer use the past behaviour of the system to predict its future state.
“At present, we do not understand what has driven this recent dramatic sea ice decline. Climate models, our best tools for understanding and making future projections of sea ice, have been notoriously bad at simulating Antarctic sea ice. Substantial effort is needed to improve these models if we are to understand both recent changes and what comes next for Antarctic sea ice.”
Conflict of interest statement: No conflicts of interest.
Professor Craig Stevens, Professor of Physics, Waipapa Taumata Rau University of Auckland, comments:
“This new report emphasises the continued pressure we are placing on our climate – and the associated environmental, economic and sociocultural systems that make life on earth worth living.
“From an overarching perspective, seeing that ocean heat content line continue inexorably higher is very concerning as so many impacts follow from this stored energy. I have a particular worry that the upper ocean is going to warm so much so that it will affect how further incoming heat is stored.
“These factors were brought home to me in January and February when I was aboard NIWA’s research vessel Tangaroa for its two-yearly voyage to the Ross Sea and the reduction in sea ice throughout the region was obvious – we got to go places that had always been off limits. Reduced sea ice cover changes the reflectivity of the planet, changes thermal exchange between air and sea, changes the properties of the deep ocean, and reduces critical habitat for key parts of the Southern Ocean’s ecosystem.
“I was part of a group of Aotearoa New Zealand scientists who held a Sea Ice Emergency Summit in 2023 on how these changes around Antarctica would affect us here in Aotearoa. The Summit highlighted the importance of taking these changes seriously, and responding accordingly at a range of levels. This new WMO report continues that message.”
Conflict of interest statement: I am a science advisor for the Ministry for the Environment and primarily funded by MBIE’s Strategic Science Investment Fund.
Our colleagues at the UK Science Media Centre also gathered comments.
Prof. Stephen Belcher, UK Met Office chief scientist, comments:
“The latest planetary health check tells us that earth is profoundly ill. Many of the vital signs are sounding alarms.
“Globally, earth has experienced the ten warmest years on record over the last ten years. And at both poles we are seeing record loss of sea ice, while the largest three-year loss of glacier mass on record has occurred in the past three years.
“Without serious efforts to heed the warnings, extreme weather events – such as drought, heatwaves and flooding – will continue to worsen.