‘Overestimated’: Study Finds ‘Climate models are overestimating ice sheet runoff by 21%-58%’ in Greenland – Published in the journal Nature Communications

https://www.yahoo.com/news/articles/scientists-discover-serious-flaw-predictions-021500797.html

By Mandy Carr

Excerpt: A new study in Greenland reveals that bare ice can act like firn ice and snow, impacting climate models and contributing to rising sea levels.


Climate models are overestimating ice sheet runoff by 21%-58% during peak summer melt conditions, leading to inaccurate predictions of sea level rise.


Rising sea levels could submerge parts of the Carolinas, Florida Keys, Miami, New York City, and Long Island by 2100, highlighting the urgent need for accurate climate models to inform adaptation strategies.


A new study conducted in Greenland is shedding new light on melting ice sheets.

According to a study published in the Nature Communications journal, the bare-ice ablation zone is acting differently than previously thought. “Climate models traditionally assume that all bare-ice runoff enters the ocean, unlike porous firn, in which some meltwater is retained and/or refrozen,” it stated.

What’s happening?


It is now believed that bare ice can act like firn ice, which is more porous, and snow. Bare ice is credited with contributing to the rising sea level. However, bare ice can also retain water and refreeze. The climate models are not accounting for this, so they are overestimating ice sheet runoff.

According to the study, “direct measurements of supraglacial runoff are overestimated by 21%-58% during peak summer melt conditions.”

The study added: “Ice sheet mass changes are overestimated by 21%-47% relative to … satellite gravity retrievals, and satellite laser altimetry measurements indicate that surface melt rates are overestimated by 14%-40%.”

Why is the miscalculation of ice sheet melt concerning?
It’s crucial that the climate models accurately calculate rising sea levels to help residents in the places that are going to be most affected. The Intergovernmental Panel estimates that the sea level will rise between 1.4 and 2.8 feet, but 6.6 feet isn’t being ruled out by 2100.

If worst-case scenarios come true, the Carolinas in the U.S. are most at risk, since three North Carolina coastal counties would be submerged in water. Charleston, South Carolina, could form new islands. Additionally, the Florida Keys, some of Miami, New York City, and Long Island would all be engulfed.

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