As humans continue to pour greenhouse gases into the atmosphere, oceans have tempered the effect. The world’s seas have absorbed more than 90 percent of the heat from these gases, but it’s taking a toll on our oceans: 2021 set a new record for ocean heating.
Rising seas is one of those climate change effects. Average sea levels have swelled over 8 inches (about 23 cm) since 1880, with about three of those inches gained in the last 25 years. Every year, the sea rises another .13 inches (3.2 mm.)
New research published on February 15, 2022 shows that sea level rise is accelerating and projected to rise by a foot by 2050.
That translates into as much sea level rise in the next 30 years as occurred over the last century, according to the National Oceanic and Atmospheric Administration’s latest technical data, which updates 2017 projections with the most precise estimates yet.
Rick Spinrad, the NOAA administrator, called the findings “historic,” and warned that the projected rise will occur regardless, even if carbon emissions are drastically cut.
In the United States, the most vulnerable populations live on the East and Gulf Coasts, where damaging flooding is predicted to occur 10 times more often in 2050 than it does today.
The change in sea levels is linked to three primary factors, all induced by ongoing global climate change:
Thermal expansion: When water heats up, it expands. About half of the sea-level rise over the past 25 years is attributable to warmer oceans simply occupying more space.
Melting glaciers: Large ice formations such as mountain glaciers naturally melt a bit each summer.
In the winter, snows, primarily from evaporated seawater, are generally sufficient to balance out the melting.
Recently, though, persistently higher temperatures caused by global warming have led to greater-than-average summer melting as well as diminished snowfall due to later winters and earlier springs.
That creates an imbalance between runoff and ocean evaporation, causing sea levels to rise.
When sea levels rise as rapidly as they have been, even a small increase can have devastating effects on coastal habitats farther inland, it can cause destructive erosion, wetland flooding, aquifer and agricultural soil contamination with salt, and lost habitat for fish, birds, and plants.
Higher sea levels are coinciding with more dangerous hurricanes and typhoons that move more slowly and drop more rain, contributing to more powerful storm surges that can strip away everything in their path. One study found that between 1963 and 2012, almost half of all deaths from Atlantic hurricanes were caused by storm surges.