A NASA-led study has revealed that global sea levels rose at a higher-than-expected rate in 2024, continuing a troubling trend of rapid acceleration over the past three decades. The average rise last year was 0.23 inches (0.59 cm), surpassing the predicted 0.17 inches (0.43 cm). This unexpected increase has raised alarms, particularly for coastal cities already struggling with more frequent and severe flooding.
Since 1993, global sea levels have climbed by approximately 4 inches (10 cm), with the annual rate of rise more than doubling. “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,” said NASA sea-level researcher Josh Willis.
While melting ice sheets and glaciers have historically been the primary contributors to rising sea levels, 2024 saw an unusual driver: extreme ocean warming. Warmer waters expand, taking up more space and pushing sea levels higher. Scientists have been stunned by the recent surge in ocean heat, which has skyrocketed to unprecedented levels over the past two years. Some now believe this warming may have permanently altered Earth’s climate system beyond human-scale recovery.
The consequences of rising sea levels are becoming increasingly severe. Marine ecosystems, including coral reefs, are suffering from extreme temperatures, and warm waters are fueling more intense storms. Hurricane Milton in 2024, for example, rapidly intensified due to record ocean heat.
The effects of sea level rise are also being felt unevenly across different regions. Some coastal areas are experiencing even greater increases due to local factors such as land subsidence, ocean currents, and variations in land elevation. Tide gauges from Texas to North Carolina indicate that sea levels in these areas have risen by at least 6 inches in the past 15 years, making flooding more frequent and dangerous—especially in historically marginalized communities.
