It says here that the ice cover of Greenland is melting because of underground thermal activity.
But wait a minute.... didn't famous climate scientist Great Thunberg say...
oh my, and I thought my gas-belching car was the problem.
Thanks Gunter,
This surely is contributing to some of the warming of Greenland ice.
I had to chuckle at the way CNN reported recently to frame the recent ice melting in Greenland.
To start with, I have always acknowledged that we have global warming/climate change(mostly beneficial) and that the warming is causing melting ice on Greenland. The exaggerated amount of warming on models and MSM reports, has resulted in exaggerated estimates for melting ice on Greenland and exaggerated increasing sea levels.
With temps going higher, not lower its very expected that ice melting would increase in Greenland(by me). What other result could anybody expect, right?
Here is how CNN reported it a couple of months ago. I have numerous comments:
"Over the last two decades, Greenland's ice sheet has melted at a rate of roughly 6,100 billion tons per century, a rate approached only during a warm period that occurred between 7,000 and 10,000 years ago."
The big difference between now and then? The influence of human activity.
The melting seen today is driven primarily by greenhouse gas emissions, whereas the warming that occurred thousands of years ago was a result of natural climate variability, Briner said.
How much Greenland melts going forward is up to us.
Under a scenario where humans continue to raise concentrations of heat-trapping gases in the atmosphere, Greenland's ice loss could reach unprecedented levels, with more than 35,900 billion tons of ice potentially lost by the end of this century.
Right now, Briner says current melt rates track closely with this worst-case scenario.
metmike: Where to start (-:
First of all, 99.99% of people would never know the information I'm providing and will just believe CNN, their interpretation and their source. How would they know different.
Ice core data tells us that the ice in Greenland's farthest north/coldest glacier completely melted away, sometime during the Holocene Climate Optimum(between 9,000-5,000 years ago).
All the ice there today, started rebuilding 4,000 years ago.
"The Hans Tausen Iskappe (ice cap) in Peary Land (northern Greenland) was drilled in 1977 with a new deep drill to 325 m. The ice core contained distinct melt layers all the way to bedrock indicating that Hans Tausen Iskappe contains no ice from the last glaciation; i.e., the world's northernmost ice cap melted away during the post-glacial climatic optimum and was rebuilt when the climate got colder some 4000 years ago.[12]"
"Out of 140 sites across the western Arctic, there is clear evidence for conditions warmer than now at 120 sites. At 16 sites, where quantitative estimates have been obtained, local HTM temperatures were on average 1.6±0.8 °C higher than now. Northwestern North America had peak warmth first, from 11,000 to 9,000 years ago, while the Laurentide Ice Sheet still chilled eastern Canada. Northeastern North America experienced peak warming 4,000 years later. Along the Arctic Coastal Plain in Alaska, there are indications of summer temperatures 2–3 °C warmer than present.[5] Research indicates that the Arctic had less sea ice than the present.[6]
https://en.wikipedia.org/wiki/Holocene_climatic_optimum
So they supposedly know that the warming back then was natural and all of this warming is manmade but they are only speculating on what caused the warming back then (Milenkovich Cycle-which is probably right). And the current warming started 200 years ago when we broke out of the Little Ice Age. So what caused the current warming the first 120-150 years before increasing CO2 added to it? No Milenkovich Cycle this time (-:
And they link to this article. Look whats embedded in that one but never got headlines in those 2 years:
https://www.cnn.com/2020/08/20/weather/greenland-ice-sheet-melt-climate-intl-hnk/index.html
"Sasgen said that these ever-increasing temperatures combined with a low snowfall, and warm atmospheric and cloud-free conditions that allowed more solar radiation to enter the ice sheet, led to the huge melt production seen last year.
Interestingly, two colder years that preceded 2019 saw a reduction in the ice melt. Satellite data found that Greenland's ice loss in 2017 and 2018 was lower than in any other two-year period between 2003 and 2019, due to two abnormally cold summers in western Greenland, a snowier fall and winter conditions in the east, according to the report."
metmike: I'm not even close to saying that the Greenland ice sheet is not melting pretty fast and that this will not continue or that we don't have global warming or that the seas are not increasing but we need to report all the facts accurately, even when they don't fit the apocalyptic narrative.
Truth on Rising Sea levels
Started by metmike - Dec. 5, 2020, 11:24 a.m.
On the amount of ice melt from global warming and amount from geothermal heat from below.
We can guess about the amount from geothermal heat and it doesn't appear that we have enough data for accurate estimates.
With global warming from the atmosphere, we have pretty accurate measurements of surface temperatures that are pretty good at showing how much warmer Greenland has been the last 2 decades compared to previous decades.
There are many other complicating items too, like erosion of the ice sheets from the outside/receeding/shrinking them, melting in the center that refreezes and calving(where a growing glacier actually pushes forward and melts). Unusually heavy snowfalls over extended periods can make up for some of the erosion.
To be honest, I have alot to learn about these processes and am taking this opportunity to share some of it(with me learning too).
https://www.britannica.com/place/Greenland-Ice-Sheet
In volume it contains 12 percent of the world’s glacier ice, and, if it melted, sea level would rise 20 feet (6 m).
https://nsidc.org/cryosphere/quickfacts/icesheets.html
Together, the Antarctic and Greenland ice sheets contain more than 99 percent of the freshwater ice on Earth. The Antarctic Ice Sheet extends almost 14 million square kilometers (5.4 million square miles), roughly the area of the contiguous United States and Mexico combined. The Antarctic Ice Sheet contains 30 million cubic kilometers (7.2 million cubic miles) of ice. The Greenland Ice Sheet extends about 1.7 million square kilometers (656,000 square miles), covering most of the island of Greenland, three times the size of Texas.
Ice sheets form in areas where snow that falls in winter does not melt entirely over the summer. Over thousands of years, the layers of snow pile up into thick masses of ice, growing thicker and denser as the weight of new snow and ice layers compresses the older layers.
Ice sheets are constantly in motion, slowly flowing downhill under their own weight. Near the coast, most of the ice moves through relatively fast-moving outlets called ice streams, glaciers, and ice shelves. As long as an ice sheet accumulates the same mass of snow as it loses to the sea, it remains stable
The mass of ice in the Greenland Ice Sheet has begun to decline. From 1979 to 2006, summer melt on the ice sheet increased by 30 percent, reaching a new record in 2007. At higher elevations, an increase in winter snow accumulation has partially offset the melt. However, the decline continues to outpace accumulation because warmer temperatures have led to increased melt and faster glacier movement at the island's edges. To learn more about research on the Greenland Ice Sheet, visit former CIRES Director Konrad Steffen's research Web page (http://cires1.colorado.edu/science/groups/steffen/).
Most of Antarctica has yet to see dramatic warming. However, the Antarctic Peninsula, which juts out into warmer waters north of Antarctica, has warmed 2.5 degrees Celsius (4.5 degrees Fahrenheit) since 1950. A large area of the West Antarctic Ice Sheet is also losing mass, probably because of warmer water deep in the ocean near the Antarctic coast. In East Antarctica, no clear trend has emerged, although some stations appear to be cooling slightly. Overall, scientists believe that Antarctica is starting to lose ice, but so far the process has not become as quick or as widespread as in Greenland.
https://nsidc.org/cryosphere/icelights/2011/09/greenland%E2%80%99s-glaciers-and-arctic-climate
In August 2010, Greenland’s Petermann Glacier calved an iceberg. The iceberg that broke off from the Petermann was roughly 97 square miles (251 square kilometers). In July 2012, the glacier calved another ice island.
On a stable glacier, iceberg calving is a natural process that may release a large iceberg every few decades. When glacier calving accelerates, the glacier’s flow speed may also accelerate because the backpressure of the glacier front, buoyed by ocean water, has decreased.
Jason Box, professor in glaciology at the Geological Survey of Denmark and Greenland, has closely studied the Petermann Glacier, as well as the climate and ice of Greenland as a whole. He said, “Petermann is not the only loser in Greenland. In fact, there is a very clear pattern of glacier area loss all around the island.” Still, climatologists cannot blame the Petermann glacier event—or any specific ice breakup—squarely on climate change. There are too many variables that determine exactly when a glacier calves. Box said, “A single cracking event could conceivably be triggered by a seagull, acting like the straw that broke the camel’s back.” Data compiled by Box show that air temperatures in Greenland have risen sharply since the mid-1980s. The extent of melting and ice retreat has accordingly increased.
Studies show that the ice on land and ice on the ocean surface are intimately related. The decline in sea ice surrounding Greenland could speed up ice loss from the Greenland Ice Sheet. The Greenland Ice Sheet covers roughly 1.7 million square kilometers (650,000 square miles). This ice sheet is so massive that, if it melted away completely, global sea level could rise roughly 7 meters (23 feet).
To assess an ice sheet’s contribution to sea level, scientists track its mass balance. Mass balance is the difference between the ice sheet’s total growth from snow, and its total loss from melt, evaporation, and/or calving. So long as an ice sheet gains as much as it loses, glaciologists consider the ice sheet to be in balance. If an ice sheet is losing more than it is gaining—including losing ice from calving—global sea level could be on the rise.
Box said, “It is reasonable to speculate that changes in sea ice duration and concentration in the vicinity of glacier fronts should impact their stability. As the sea ice melts, the ocean can be stirred up more by strong Arctic winds and change fjord water circulation and the sub-marine melt regime.” Winter sea ice also acts as a buttress against glacier ice flow, seasonally slowing the flow speed. An earlier break-up and later freeze-up of sea ice in the fjords may play a role in the ice sheets’ mass balance.
Sea ice reflects most of the sunlight that reaches its surface. Ice-free ocean water absorbs nearly all of the sunlight that reaches its surface. Seawater’s energy absorption may affect more than ocean temperature.
A study published in 2017 found that when sea ice in Baffin Bay, just west of Greenland, starts melting unusually early in the spring, that melt correlates with early onset of melt on the ice sheet. The study’s authors suggested that sea ice retreat in Baffin Bay increases the transfer of heat from the ocean to the atmosphere over the Greenland Ice Sheet, increasing surface melt. The correlation between sea ice melt and ice sheet melt was modest, and the authors pointed out that other factors were also at work, such as regional air temperatures.
Sea ice melt does not contribute to sea level rise, just as ice melting in a cold drink will not raise the liquid level in the glass. But the miles of ice that cover Greenland are different: if that ice melts, it would be like adding more ice cubes to that glass.