Ice pouring into ocean waters could trigger a sea-level rise known as a ‘pulse,’ regarded as climate change’s worst scenario for coastal cities like Miami, Florida.
The event could be caused by abnormally warm water pooling underneath the Antarctic glaciers that hold back massive ice sheets, causing them to collapse, Business Insider reported. As a result, massive quantities of ice would pour into the oceans and cause a dramatic rise in sea-levels around the world.
Scientists say such a scenario means the predictions for vulnerable coastal cities are far too low, especially if superstorms accompany the phenomenon.
Take Miami for example.
Initially experts said that, by the end of the century, sea levels would creep up to seven or eight feet higher but, in the event of a pulse, these sea-levels could rise by 10 to 30 feet by 2100.
A recent study published in the journal Science Advances noted this previously undocumented occurrence, with glacial meltwater leading to the melting of ice shelves.
Researchers found that glacier meltwater was leading to the ocean’s surface layer being less salty and more buoyant, which ultimately was slowing ocean currents and preventing the formation of cool water.
“Our study shows that this feedback process is not only possible but is in fact already underway, and may drive further acceleration of the rate of sea level rise in the future,” said Alessandro Silvano, lead author of the study.
“Currently the ice shelves resist the flow of ice to the ocean, acting like a buttress to hold the ice sheet on the Antarctic continent. Where warm ocean waters flow under the ice shelves they can drive rapid melting from below, causing ice shelves to thin or break up and reducing the buttressing effect.”
Silvano said this process would lead to rising sea levels as more ice poured into the ocean.
In a report, NASA noted that the Greenland and West Antarctic ice sheets could raise sea levels by 10 metyers if they were melted completely and, with the projected global temperature rise for 2100 of 0.8°-3.2°C, this could destabilize Greenland irreversibly.