Nature's fury: 30-year-old prediction model saw the rise of sea levels coming! (And it's happening!)

Rising sea levels are one of the alarming signs of global warming, caused by melting glaciers, disappearing ice sheets, and the warming and expansion of seawater. This gradual yet relentless shift, is one of the most stark signs of a changing climate.Understanding the rise of sea levels has historically depended on familiar coastal markers and tide gauges, but satellites have advanced our viewing techniques on our view of the oceans with technology monitoring the sea-surface heights.A new study published in Earth’s Future compares satellite-era sea-level observations with projections from the mid-1990s, and finds they aligned better than expected. This research, led by Torbjörn Törnqvist from Tulane University, shows that climate predictions made decades ago have turned out to be surprisingly accurate.

The predicted rise in sea levels was nearly correct!

As Törnqvist says in the study, “The ultimate test of climate projections is to compare them with what has played out since they were made, but this requires patience—it takes decades of observations,”. Despite the simplicity of early models, the projections closely matched reality. The mid-1990s IPCC assessment forecasted nearly 8 cm of global sea-level rise over 30 years, which was very close to the 9 cm actually observed.

Co-author Sönke Dangendorf says that local planning depends on regional forecasts, not just global averages: “Sea level doesn’t rise uniformly—it varies widely.” He also says that it is important to turn big-picture predictions into useful, local forecasts that people can actually plan around.

What are the reasons for the accelerated rise in sea levels

Still, the old models did underplay contributions from ice sheets. The melting of Greenland and Antarctica added over 2 cm more than initially predicted.

At the time, scientists knew little about how warming oceans destabilise Antarctic ice or increase Greenland’s flow into the sea. Groundwater depletion also added to ocean volumes more than expected.

NASA says that there is an increase in rising sea levels!

NASA reports that sea-level rise has not just continued but sped up. In 2024, global sea levels climbed by 0.59 cm, higher than the expected 0.43 cm. As NASA oceanographer Josh Willis says on its Sea Level Change portal, “Every year is a little bit different, but what’s clear is that the ocean continues to rise, and the rate of rise is getting faster and faster.”

The year also broke records as the warmest on Earth, and for the first time, thermal expansion, the warming and expansion of seawater, accounted for two-thirds of that rise, reversing prior trends in which melting ice dominated.