Here’s a shocking fact: despite record-breaking ocean temperatures, global sea levels rose less than expected in 2025. But here’s where it gets fascinating—a mild La Niña event played a surprising role in curbing this rise. How? By dumping extra rainfall over the Amazon basin, effectively shifting water from the oceans to land. And this is the part most people miss: this temporary reprieve won’t last long, as that water will soon make its way back to the seas, reigniting the rapid rise in sea levels.
According to NASA, the global mean sea level increased by just 0.03 inches (0.08 centimeters) in 2025, a significant drop from the 0.23 inches (0.59 centimeters) recorded in 2024. This slowdown was largely due to La Niña, a phase of the El Niño-Southern Oscillation cycle that cools the eastern Pacific Ocean and often triggers heavy rainfall in equatorial South America. While sea levels have been on an upward trend since the early 1990s, years with slower rises often coincide with La Niña events.
But let’s dive deeper. The 2025 rise was even below the long-term expected rate of 0.17 inches (0.44 centimeters) per year. This anomaly highlights the complex interplay between climate phenomena like La Niña, melting ice sheets, and ocean warming. While La Niña temporarily lowered sea levels by redirecting water to land, the oceans themselves were warmer than ever, a trend that typically causes water to expand and sea levels to rise.
Here’s the controversial part: Some might argue that this slowdown suggests climate change isn’t as dire as predicted. But experts caution against drawing such conclusions. Josh Willis, a sea level researcher at NASA’s Jet Propulsion Laboratory, explains, “The weather gives us a wild ride, and what we saw with sea level rise last year is part of that ride. But that cycle is short-lived. The extra water in the Amazon is going to reach the oceans in less than a year, and rapid rise will soon return.”
To understand these dynamics, scientists relied on data from multiple sources. The Sentinel-6 Michael Freilich satellite, the current gold standard for sea level measurements, provided critical insights. Meanwhile, the GRACE-FO mission tracked water movement by measuring changes in Earth’s gravity, revealing how La Niña shifted water from oceans to the Amazon. And the Argo program confirmed record ocean warming in 2025, underscoring the ongoing threats of climate change.
The combined effect of these factors—La Niña’s rainfall offsetting ocean warming—resulted in a lower-than-average sea level rise. But this balance is precarious. As Nadya Shiffer, head of physical oceanography programs at NASA, notes, “As seas continue to rise globally, satellite monitoring empowers communities worldwide to anticipate risks and build resilience.”
Over the past three decades, satellites like TOPEX/Poseidon, Jason-3, and now Sentinel-6 Michael Freilich (and its twin, Sentinel-6B, launching soon) have provided actionable, accurate, and consistent data. This information is vital for flood predictions and safeguarding coastal communities. Since 1993, global sea levels have risen by 4 inches (10 centimeters), with the annual rate more than doubling.
So, here’s the question for you: Does this temporary slowdown in sea level rise give us reason to breathe easy, or is it a stark reminder of the unpredictable nature of climate change? Let us know your thoughts in the comments—we’d love to hear your perspective!
