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Greenland’s menacing meltwater and how a story saves us from climate change with more green lands
Ocean River Institute, Inc Ocean River Institute, Inc
For Immediate Release:
Dateline: Cambridge, MA
Tuesday, March 14, 2023


“Greenland lost a record amount of ice during an extra warm 2019, with the melt massive enough to cover California in more than four feet (1.25 meters) of water.

This report was alarming for many who relied on experts’ findings, particularly regarding climate change. It was not scary for those who paid attention in Geography class and knew what the world looked like. Greenland is the largest island in the world.   If Greenland were a nation (the Danes claim it as part of their nation) at 836,300 square miles, it would be the twelfth largest country.

Greenland is large enough to hold five California and has room for two New Hampshire.  Water covering California four feet deep would fill a pool the size of Greenland nine inches deep. If the Atlantic Ocean were a pool, which it is, that much melt water would fill the pool two-tenths of an inch. If the surface of the world’s ocean were a pool, Greenland meltwater would fill six-hundredths of an inch.

This reporting is more deceptive than simply one of scale; readers need to understand the immensity and workings of the ice sheet that covers about 80% of Greenland. The meltwater, pooled on top of the ice sheet, was observed from satellites.  The water sits on top of 6,600 to 9,800 feet of ice.  No one knows if more or less than 50% of it will refreeze.  Likely much of it will turn back to ice.

Given how scorching it has been in Greenland and the intense growing season with twenty-four hours of daylight, rates of plants taking up water to photosynthesize increased. Along the west coast of Greenland, the ice sheet is about sixty miles inland.  The land between those places where it is not vertical rock (about the size of California) is covered with vegetation that grows up to swallow boulders into waist-high forests.  When all live by the coast, it is curious that no one has reported increased water flowing into the sea.  The last bridge to be damaged by rushing waters was in 2012.

Nonetheless, the story of massive amounts of Greenland meltwater benefits us all because it has raised concerns that too much water running into the sea is not good.  This new concept unites the land with the sea; they are not separate ecosystems.  What we do on the land impacts life in the ocean. Finally, we are thinking globally about the water cycle, life on earth, and how it’s all interconnected, one blue-green planet.

“Climate change will lead to a slower Gulf Stream system in the future, as melting ice sheets in Greenland disrupt the system with discharges of cold fresh water.”

This is when the former science teacher, a marine educator, bangs his head against the wall. Science is a process of questioning, observing, recording, and communicating.  How does the foot of meltwater perched on more than a mile of ice relate to the Gulf Stream?  To refresh, the oceans hold about 96.5% of the world’s water.  The amount of global water locked up in ice and snow is only about 1.7% (1.17% in ice caps and glaciers).  Greenland meltwater has no more effect on the Gulf Stream than would Mark Twain’s cup of tea slow the flow of the Mississippi River.

There’s nothing new here. Water has been running off the land and out onto the surface of the seas since surf and turf first met.  Sailors knew when they were off the coast of Brazil, even when there was no land in sight, because the ocean water tasted fresh.  Amazon River water spreads up to forty miles over the sea’s face.  Beneath this fresh water, the Brazil Current flows unfettered at about 11 Sverdrups (1,200 cubic meters per second).

“Gulf of Maine sees second-hottest year on record, ‘getting to the edge of habitability.’”

Here’s another scale of foolery. Over ten years, surface ocean waters in the Gulf of Maine, between Cape Cod and Nova Scotia, were found to be warmest when summers were hot and wet. Ocean waters were not as hot when summers were hot but without as much rainfall.  Surface water temperatures were even cooler when summers were cool and moist.  The last summer of the study happened to be the wettest and hottest.  No surprise that ten years showed an increase in average surface water temperatures.

This is not a coincidence. There is a causal relationship between rainfall amounts, land temperature, and sea surface temperature because the measured ocean waters came from off the land. Like the meltwater in Greenland, it lies over the briny deep.

The Gulf of Maine is a sea beside the sea because it is separated from the Atlantic Ocean by Cape Cod, Georges Bank, Browns Banks, and Nova Scotia.  There’s more salt in the Atlantic, with 36 parts per thousand salinity. Salinity in the Gulf of Maine is 34 parts per thousand due to freshwater input from the land.  The Gulf of Maine is nearly a closed system with a counterclockwise current or gyre that turns fastest when rivers flow strongest, less so during the winter.  Much of what happens in the Gulf of Maine stays in the Gulf of Maine, including young lobster larvae in the plankton that later settle onto the ocean floor.

Another change occurs in the north, where the Arctic Ocean has less sea ice and more open water. Once a tiny fraction is open, nearly all of the Arctic Ocean is recently open and turns to sea ice in October.  When sea ice forms, it is composed of freshwater because it freezes at a higher temperature than salt water.  The salts are concentrated in the icy water next to the ice.  This is the densest possible seawater, so it sinks and displaces water below, driving the thermohaline circulation outwards.

In the Denmark Straits by Greenland, colder, nutrient-rich Arctic Ocean water jets through the confined rocky landscapes to collide with warm, nutrient-poor Atlantic Water. The denser water dives 11,000 feet below the Atlantic Water to become the Greenland Current and, later, in Baffin Bay, the Labrador Current.  Some of the Labrador Current enters the Gulf of Maine. The amount varies annually and is unpredictable. The difference is filled in by Continental Slope Water, a water body with its signature temperature and salinity floating above the Labrador Current.  Much of the Labrador flows south to propel the northward Gulf Stream at 35 Sverdrups (the flow strength of three Brazil Currents).

In 2011, the Gulf Stream demonstrated it was flowing stronger, dissipating more energy, by meandering up onto the continental shelf, closer to Rhode Island than ever before.  In 2007, in the Svalbard Archipelago at the threshold between the Atlantic and Artic Oceans, warm Gulf Stream water surfaced to begin melting glaciers on the land.  In 2017, Svalbard was recognized as the end-of-the-line dump for plastic wastes transported by the Gulf Stream.  Warmer water entered the Arctic Ocean midwater current to flow beneath the surface waters, further accelerating sea ice loss in a positive feedback loop.

The moral is that when we slow water down and reduce the water flowing into the sea, we can stop the warming of ocean surface waters, including the Gulf of Maine.  Research indicates that retaining water in our landscapes, soils, and biomass can reduce sea level rise by as much as 25%.  Even if this number is smaller, our quality of life has been improved with the absence of drought conditions and fewer damages from extreme rain events. Rather than being alarmed by Greenland meltwater, let’s be motivated to look at how we may have more green lands and less impervious surfaces in our places of habitation.

The Ocean River Institute provides opportunities to make a difference and go the distance for savvy stewardship of a greener and bluer planet Earth.  www.oceanriver.org 

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Name: Rob Moir
Title: Director
Group: Ocean River Institute
Dateline: Cambridge, MA United States
Direct Phone: 617-714-3563
Main Phone: 617 714-3563
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