Day: November 20, 2025

From Watts Up With That?

By Anthony Watts

Every few months, a new study emerges claiming to have finally cracked the code on why the Maldives—or Kiribati, Tuvalu, or whichever island chain is the fashionable climate casualty of the moment—are supposedly on the verge of disappearing under rising seas. They never quite do, of course, but that fact rarely stops the press releases. The latest entry comes from the University of Plymouth and Deltares, announcing with great fanfare that the Maldives may soon face flooding events “every two to three years by 2050,” based on modeling of a rare July 2022 swell-driven flood.

You can read the press release yourself here: Study provides new forecasts of remote islands’ vulnerability to sea level rise (EurekAlert!, University of Plymouth). I encourage you to read it closely, because what is buried inside is a story less about island vulnerability and more about modeling overreach—yet again.

The narrative is predictable: a single unusual event is simulated, extrapolated, and then turned into a headline-worthy forecast of future doom. What goes largely unmentioned is the inconvenient fact that the peer-reviewed literature overwhelmingly shows that reef islands—including those in the Maldives—have been stable or growing for decades, and that their natural geomorphic processes often make them more resilient in the face of rising seas, not less.

Here at Watts Up With That, I’ve spent nearly two decades highlighting these uncomfortable facts. And because the press release slyly acknowledges some of those same processes but then stuffs them behind the modeling curtain, it’s worth digging into what the science says, what the models assume, and what real-world data continues to show: the Maldives are not drowning. Look at the data:

A Rare Flooding Event—But a Convenient One

Let’s start with what the press release says upfront:

“In the summer of 2022, 20 islands in the Maldives were flooded when a distant swell event in the Indian Ocean coincided with an extremely high tide level.”

The authors admit this was “a relatively rare occurrence” and the worst flooding since the 2004 tsunami. That should be our first clue: linking a common swell event with an extreme high-tide coincidence is not a harbinger of climate-driven catastrophe. It’s simply a rare confluence of natural factors. Yet this single event becomes the backbone of the model’s prediction that such events will happen “every two to three years by around 2050.” That phrase—by around 2050—deserves its own eyebrow raise. It’s not a measurement. It’s not even a trend. It’s a scenario extrapolated from a model driven by assumed sea-level rise rates and closed-box geomorphic behavior. And that’s the central flaw: models can only produce results consistent with the assumptions embedded into them. If you assume islands are static sandpiles in a rising bathtub, you shouldn’t be surprised when the model says they get wetter.

The Press Release Accidentally Tells the Real Story

Buried in the release is a short sentence that contradicts the entire catastrophe narrative:

“Waves washing over an island can deposit coral sand and rubble… raising its elevation and potentially making it more resilient to future flooding events and sea-level rise.”

That single line—almost tossed in as an afterthought—summarizes two decades of geomorphological research on reef islands. It confirms what real measurements, aerial surveys, and long-term shoreline studies have shown: atolls are dynamic landforms that respond to environmental forces by adjusting, migrating, accreting, and sometimes even expanding vertically. These are not static mounds of sand the way modelers often treat them. They are living systems connected to coral reefs, sediment supply, storm dynamics, and wave climates.

This process—overwash deposition—is not a theory. It is a documented mechanism shaping reef islands globally, including the Maldives. And yet, after admitting this, the press release immediately pivots back to the model’s forecast of increased flooding. The contradiction is obvious: if overwash can raise island elevation, and if atoll islands have repeatedly done so over decades, then a model that excludes island adaptation cannot validly predict their future vulnerability.

The Models Used Don’t Include Island Adaptation—And the Authors Admit It

The key sentence in the release is this:

“The model did not factor in natural or anthropogenic adjustments over the next quarter of a century…”

That is a polite way of saying: We built a model that assumes the islands will not change at all, then used that assumption to claim that they won’t be able to change enough to keep up with rising seas. This is like modeling the future of forests but disallowing tree growth. Or predicting the trajectory of a living reef while assuming coral calcification ceases tomorrow. In the real world, reef islands adjust continually through: sediment overwash, lagoon infilling, seasonal shoreline migration, vertical accretion, and reef-supplied sediment feedback loops.

None of these mechanisms are speculative. They are documented in field studies across multiple ocean basins. But because they are difficult to model—especially at the high resolution required to simulate multi-decadal morphology—most coastal inundation models simply omit them. That’s not a criticism of XBeach itself; it’s a powerful tool for short-term storm simulation and coastal erosion. But it is not designed to model 25-year geomorphic island evolution. Yet here it is used to do exactly that.

The Peer-Reviewed Literature Paints a Very Different Picture

Let’s turn to what the research actually shows about island stability and growth. I’ll cite just a few of the most comprehensive studies.

Webb & Kench (2010), Global and Planetary Change

• In one of the most influential papers on atoll dynamics, Paul Kench and Arthur Webb examined 27 reef islands over several decades using historic aerial imagery and modern satellite data. Their findings? 86 percent of islands were either stable or increased in size. Not a single island was found to be contracting rapidly enough to justify claims of imminent disappearance.
  Link: https://doi.org/10.1016/j.gloplacha.2010.03.005

Duvat (2019), “A Global Assessment of Atoll Island Planform Change”

• Virginie Duvat undertook the largest global analysis of atoll islands ever attempted—709 islands across 30 atolls over multi-decadal timescales. Her findings: 89 percent of islands were stable or increasing in size. Only 11 percent showed any decrease, and those were primarily linked to human modifications. Link: https://doi.org/10.1016/j.earscirev.2018.10.001

Kench et al. (2018), Nature Communications

• This landmark study examined all 101 islands of Tuvalu over four decades and found that 73 percent grew in land area, some by as much as 30 percent. This occurred during a period of significant regional sea-level rise. The conclusion: “Tuvalu’s islands are not simply drowning.”
  Link: https://www.nature.com/articles/s41467-018-02954-1

Ford & Kench (2015), Geology

• This paper documented how overwash processes on atoll islands increase island elevation, enabling islands to “keep pace” with sea-level changes.
  Link: https://doi.org/10.1130/G36555.1

Kench, Owen & Ford (2014), Geophysical Research Letters

• Demonstrated how cyclone-generated sediment pulses can significantly raise island elevation.
  Link: https://doi.org/10.1002/2013GL058389

These studies do not support the idea that rising seas doom atolls. They support the exact opposite: atoll islands are remarkably resilient natural structures that evolve dynamically in response to environmental changes. This is why the Maldives—despite decades of dire predictions—have not only survived but grown in total land area.

Yes, You Read That Correctly: The Maldives Are Growing

Official Maldivian government data show that the total land area has increased in recent decades. WUWT covered this in detail here: Islands That Climate Alarmists Said Would Soon “Disappear” Due to Rising Sea Found to Have Grown in Size

Between 2000 and 2017, the Maldives added roughly 3 percent to its land area. Some islands expanded naturally; others expanded through reclamation. The point is not whether growth is natural or engineered, but that the commonly repeated narrative—that these islands are teetering on the edge of inundation—is contradicted by their actual behavior.

Meanwhile, Maldivian development tells its own story. This is not a nation behaving like it expects to drown. It is building airports, hotels, resorts, sea walls, harbors, luxury properties, and commercial centers. Among the most striking examples is the expansion of Hulhumalé, a massive reclamation project creating entirely new land that is being developed with full confidence in long-term habitability. If Maldivian officials truly believed their country was doomed to drown in the next few decades, their financial and infrastructure behavior would not look like this.

Why This Matters: Atolls Are Dynamic Landforms, Not Bathtub Islands

This is the crux of the issue. Nearly all modeling studies—including the one in the Plymouth/Deltares press release—treat atolls as static. They behave as if islands were poured out of a concrete mold in 1950 and left to erode. But as our own Willis Eschenbach points out, reef islands are the opposite of static: The Unsinkable “Sinking Atolls” Meme

Their shape, size, elevation, and position change continually. They grow vertically through overwash deposition. They migrate laterally with longshore transport. They expand with sediment from reef production. They respond to storms in ways that sometimes look destructive but often turn out to be constructive. Kench and colleagues have shown repeatedly that storm activity can carry sediment inland, thickening island cores and raising overall elevation. Islands that “flood” in one event may actually be gaining elevation through the same process. In other words, the mechanism that causes flooding can also be the mechanism that makes future flooding less likely. This is precisely what the Plymouth press release acknowledges—then ignores when it comes time to present its model results.

Models like XBeach are useful for simulating the short-term hydrodynamic response of coastlines to storm events. I have no quarrel with XBeach as a research tool. But it is not an island evolution model. It is not designed to handle multi-decadal vertical accretion, sediment sorting, coral reef sediment production, reef slope changes, or lagoon infilling. It is certainly not designed to include anthropogenic interventions like sea walls, groynes, reclamation, or harbors. And crucially, as the press release itself admits, the model includes no natural adaptation processes. Yet this omission is not a minor technical detail—it’s the entire story. Imagine modeling the future of a coral reef ecosystem while excluding coral growth. That’s what’s happening here.

The Problem With Extrapolating From a Single Rare Event

The July 2022 event was the only one of 158 storm events (from 1990 to 2023) that produced flooding at the study site under current sea-level conditions. That alone gives us a baseline frequency: roughly one event every 33 years. The model then says that with assumed sea-level rise by 2050, an additional nine storms would produce flooding. This is how we get the “every 2–3 years” projection. But this projection ignores: island elevation increases, shoreline adjustments, wave climate shifts, ENSO and Indian Ocean Dipole variability, storm track variability, and coral reef changes affecting wave attenuation.

In other words, the model’s result is not a forecast; it’s an assumption cascade. Feed the model sea-level rise. Freeze the islands in place. Press “Run.” Report the output as fact.

Atoll islands grew out of rising seas during the Holocene. They adapted to rapid sea-level changes far greater than today’s modest rise. If atolls were as fragile and static as the models assume, they would have drowned thousands of years ago. But they didn’t. They formed, expanded, and stabilized. Today’s sea-level rise is not unprecedented in magnitude or rate. Yet today’s models behave as if every inch of sea-level rise must translate to inundation because the island cannot adapt. It can. It does. It will.

Conclusion: The Larger Narrative Is Politicized—And the Maldives Know It

The Maldives government has long played a dual game:

• Presenting itself internationally as a victim of sea-level rise to attract climate finance.
• Presenting itself domestically and to tourists as a booming island destination full of new development.

These two narratives cannot both be true. And as always, money follows the doom narrative. Meanwhile, concrete, steel, dredging, reclamation, and resort construction follow the island-growth narrative. Which of these two behaviors reflects what the Maldives truly believe about their future?

The Plymouth/Deltares press release is a case study in the gap between model-based forecasting and real-world evidence. The real scientific story, supported by hundreds of surveyed islands and decades of research, is this:

• Atoll islands are not drowning.
• Most islands are stable or growing.
• Natural processes raise island elevation.
• Models that assume static islands cannot predict future vulnerability.
• Sea-level rise in the Maldives is not behaving catastrophically.
• The Maldives continue to expand and develop aggressively.

And when a press release acknowledges that overwash raises islands but then uses a model that omits that process, you know you’re reading a narrative, not a neutral scientific assessment.