Thermal Expansion 43 Percent. Glaciers And Ice Sheets Most Of The Rest. The Rate Has Doubled From 2mm Per Year Since 1960 To 4mm Per Year Since 2005. And The Gap That Was Confounding Climate Science Is Now Closed.
An international team of climate scientists has fully accounted for what is driving global sea level rise across the past six decades resolving a stubborn mystery in the field of climate science that has clouded our understanding of one of climate change’s most consequential impacts.
The study was led by climate science researchers at the Institute of Atmospheric Physics at the Chinese Academy of Sciences and included scientists from Tulane University, the NSF National Center for Atmospheric Research, the University of St. Thomas and partners in France.
It was published in Science Advances and covered by Phys.org on May 19, 2026. The findings are structured around three headline conclusions that each carry distinct scientific and policy weight.
Sea level rise is accelerating. The pace has doubled from 2mm per year since 1960 to 4mm per year since 2005. Ocean warming is a leading cause. Thermal expansion of seawater accounts for 43 percent of the rise since 1960. Melting ice and glaciers contribute most of the rest.
The doubling of the rate since 2005 is not a new observation in isolation. Satellite altimetry has been measuring sea level with increasing precision since the early 1990s, and the acceleration signal has been visible in that record for more than a decade.
What this climate science study adds is the mechanistic accounting; the ability to explain, with quantified confidence, not just that sea level is rising faster but exactly why. That distinction separates this paper from the dozens of sea level studies that preceded it.
Sea level rise is a direct consequence of human-induced climate change: global warming. It is relentless and very hard to stop. It arises from human-induced warming and the consequential expansion of the ocean, plus the addition of more and more water from melting glaciers and ice sheets. It will continue long into the future.
To understand why closing this accounting gap matters, it helps to understand what the gap actually was. For years, climate scientists faced a frustrating discrepancy: when they added up all the known contributions to sea level rise (thermal expansion of water, melt from the Greenland ice sheet, melt from the Antarctic ice sheet, melt from mountain glaciers and groundwater depletion), the numbers did not sum to what tide gauges and satellites were actually measuring at the ocean surface.
The measured rise was consistently higher than the sum of its explained parts. This was known informally as the sea level budget closure problem, and its persistence embarrassed a field that prides itself on the precision of its physical models.
The team credits their findings to advances in observing technology: corrections to satellite measurements that had been subtly changing since 2015, improved methods for estimating land motion at coastal tide gauges, and improved estimates of ice loss from Greenland and Antarctica.
These advances resolve a worrying gap between observed sea level rise and its previously calculated sources. In other words, the gap was not a sign that something was missing from the physical theory of sea level rise. It was a sign that the observational and computational tools available to measure sea level rise were not yet precise enough to capture it fully. Better instruments and better correction methods have now closed the gap.
The 43 percent thermal expansion figure deserves particular attention. When ocean water warms, it expands; a process called thermosteric rise and this expansion does not require any water to be added to the ocean at all.
It happens simply because warmer water occupies more volume than cooler water at the same pressure. The fact that thermal expansion accounts for nearly half of all sea level rise since 1960 means that even if ice sheets stopped losing mass entirely tomorrow, the ocean would continue rising for centuries simply because it is still absorbing heat that human emissions have already trapped in the climate system.
The ocean has enormous thermal inertia. It warms slowly relative to the atmosphere, but once warm, it stays warm on timescales of decades to centuries. The warming already in the pipeline; the committed warming from greenhouse gases already in the atmosphere guarantees continued thermosteric rise regardless of future emissions cuts.
For climate science and climate scientists, The ice loss picture is equally sobering. The Greenland ice sheet has been losing mass at an accelerating rate since the early 2000s, and recent studies suggest the pace of loss has again accelerated through the 2020s. The Antarctic ice sheet is more complex.
The East Antarctic Ice Sheet has historically been roughly in balance or slightly gaining mass through increased snowfall, while West Antarctica and the Antarctic Peninsula have been losing mass rapidly through glacial flow into the ocean. The new study’s improved estimates of ice loss from both sheets help resolve part of the historical discrepancy.
The 4mm per year current rate may appear modest in isolation. Four millimetres is slightly less than the thickness of a coin. But compounded across decades and concentrated in storm surge events, coastal flooding episodes and tidal flooding events, the cumulative effect is severe.
At 4mm per year sustained through 2100, the ocean would be approximately 30 centimetres higher than today by the end of the century from rate alone; not accounting for potential non-linear acceleration from ice sheet dynamics that climate models cannot yet fully capture.
For coastal cities, Jakarta, Miami, Bangladesh’s coastline, the Maldives, the Netherlands, Mumbai; the difference between 2mm per year and 4mm per year is the difference between decades of manageable adaptation and decades of emergency response.
The insurance industry, the mortgage market, municipal bond investors and coastal development planners all make decisions based on sea level projections. More accurate projections, grounded in a fully closed sea level budget, produce better-informed decisions. That is what this climate science study provides.
This climate science finding also sends a clear signal on attribution. Every contribution to the fully accounted sea level rise; thermal expansion, Greenland melt, Antarctic melt, glacier retreat is a consequence of warming. And the warming is caused by human greenhouse gas emissions. The study does not use those words in isolation. The physical accounting makes the argument for them.
To check out our previous coverage on climate science, read our articles here.
