More than 3 inches of global sea level rise over the past 30 years is partly tied to ocean thermal expansion, which scientists estimate caused about one-third to one-half of the increase.
1.5 degrees Fahrenheit of ocean-surface warming since the 1800s has made water molecules spread farther apart, so the ocean takes up more space as it absorbs most of the planet’s excess heat.
Coastal cities including Rockport, Texas, and Norfolk, Virginia, are already seeing more frequent flooding as higher seas push farther onto shore.
Faster glacier melt and continued carbon pollution are adding to the pressure, accelerating sea level rise beyond the effect of warming-driven expansion alone.