A thorough reexamination of scientific data has revealed that the rate of sea-level rise is accelerating, and the primary driver might not be what you think. While melting glaciers and shrinking ice sheets are commonly understood to contribute to sea levels creeping higher, the slow and steady expansion of our oceans often goes unseen. Yet this phenomenon is the main cause leading to higher sea levels around the world, research shows. As water in the ocean gets warmer, it expands in space – a process known as thermal expansion – meaning seawater occupies more volume. This expansion of water is...