Greenland is melting faster than scientists previously thought—and will likely lead to faster sea level rise—thanks to the continued, accelerating warming of the Earth's atmosphere, a new study has found.
Scientists concerned about sea level rise have long focused on Greenland's southeast and northwest regions, where large glaciers stream iceberg-sized chunks of ice into the Atlantic Ocean. Those chunks float away, eventually melting. But a new study published Jan. 21 in the Proceedings of the National Academy of Sciences found that the largest sustained ice loss from early 2003 to mid-2013 came from Greenland's southwest region, which is mostly devoid of large glaciers.
"Whatever this was, it couldn't be explained by glaciers, because there aren't many there," said Michael Bevis, lead author of the paper, Ohio Eminent Scholar and a professor of geodynamics at The Ohio State University. "It had to be the surface mass—the ice was melting inland from the coastline."
That melting, which Bevis and his co-authors believe is largely caused by global warming, means that in the southwestern part of Greenland, growing rivers of water are streaming into the ocean during summer. The key finding from their study: Southwest Greenland, which previously had not been considered a serious threat, will likely become a major future contributor to sea level rise.
"We knew we had one big problem with increasing rates of ice discharge by some large outlet glaciers," he said. "But now we recognize a second serious problem: Increasingly, large amounts of ice mass are going to leave as meltwater, as rivers that flow into the sea."
The findings could have serious implications for coastal U.S. cities, including New York and Miami, as well as island nations that are particularly vulnerable to rising sea levels.
And there is no turning back, Bevis said.
"The only thing we can do is adapt and mitigate further global warming—it's too late for there to be no effect," he said. "This is going to cause additional sea level rise. We are watching the ice sheet hit a tipping point."
Climate scientists and glaciologists have been monitoring the Greenland ice sheet as a whole since 2002, when NASA and Germany joined forces to launch GRACE. GRACE stands for Gravity Recovery and Climate Experiment, and involves twin satellites that measure ice loss across Greenland. Data from these satellites showed that between 2002 and 2016, Greenland lost approximately 280 gigatons of ice per year, equivalent to 0.03 inches of sea level rise each year. But the rate of ice loss across the island was far from steady.
Bevis' team used data from GRACE and from GPS stations scattered around Greenland's coast to identify changes in ice mass. The patterns they found show an alarming trend—by 2012, ice was being lost at nearly four times the rate that prevailed in 2003. The biggest surprise: This acceleration was focused in southwest Greenland, a part of the island that previously hadn't been known to be losing ice that rapidly.
Bevis said a natural weather phenomenon—the North Atlantic Oscillation, which brings warmer air to West Greenland, as well as clearer skies and more solar radiation—was building on man-made climate change to cause unprecedented levels of melting and runoff. Global atmospheric warming enhances summertime melting, especially in the southwest. The North Atlantic Oscillation is a natural—if erratic—cycle that causes ice to melt under normal circumstances. When combined with man-made global warming, though, the effects are supercharged.
"These oscillations have been happening forever," Bevis said. "So why only now are they causing this massive melt? It's because the atmosphere is, at its baseline, warmer. The transient warming driven by the North Atlantic Oscillation was riding on top of more sustained, global warming."
Bevis likened the melting of Greenland's ice to coral bleaching: Once the ocean's water hits a certain temperature, coral in that region begins to bleach. There have been three global coral bleaching events. The first was caused by the 1997-98 El Niño, and the other two events by the two subsequent El Niños. But El Niño cycles have been happening for thousands of years—so why have they caused global coral bleaching only since 1997?
"What's happening is sea surface temperature in the tropics is going up; shallow water gets warmer and the air gets warmer," Bevis said. "The water temperature fluctuations driven by an El Niño are riding this global ocean warming. Because of climate change, the base temperature is already close to the critical temperature at which coral bleaches, so an El Niño pushes the temperature over the critical threshold value. And in the case of Greenland, global warming has brought summertime temperatures in a significant portion of Greenland close to the melting point, and the North Atlantic Oscillation has provided the extra push that caused large areas of ice to melt".
Before this study, scientists understood Greenland to be one of the Earth's major contributors to sea-level rise—mostly because of its glaciers. But these new findings, Bevis said, show that scientists need to be watching the island's snowpack and ice fields more closely, especially in and near southwest Greenland.
GPS systems in place now monitor Greenland's ice margin sheet around most of its perimeter, but the network is very sparse in the southwest, so it is necessary to densify the network there, given these new findings.
"We're going to see faster and faster sea level rise for the foreseeable future," Bevis said. "Once you hit that tipping point, the only question is: How severe does it get?"
Explore further:
Modest warming risks 'irreversible' ice sheet loss, study warns
More information:
Michael Bevis el al., "Accelerating changes in ice mass within Greenland, and the ice sheet's sensitivity to atmospheric forcing," PNAS (2019). www.pnas.org/cgi/doi/10.1073/pnas.1806562116
Anonym518498
Jan 21, 2019howhot3
Dug
Because now there is someone to measure it. Which begs the question as to how good their respective historic metrology benchmarks and proxies really are for comparison?
aksdad
http://sealevel.colorado.edu/
grandpa
Da Schneib
ChucktheCanuck
MR166
Well that is a question for the next scare that NASA need funding for. It seems that Illegal Space Aliens are draining our oceans at night and irrigating other planets. Only Trillions more to NASA can stop the theft or soon our oceans will be empty.
Da Schneib
MR166
And don't forget that Antarctica is melting 6x faster.
Yet no sea level rise. This theft of our precious water must be stopped before we have no oceans left.
Of course the other possibility is that the poles are just fine and it is the theft of taxpayer dollars that must be stopped.
Da Schneib
Next?
malapropism
Hmm, three observations on the link you provided that seem to indicate that your comment is wrong:
1. The title of the paper is given as, "Climate-change–driven accelerated sea-level rise detected in the altimeter era", which would seem to be saying that sea levels are rising and that the rise is accelerating.
2. Reading the paper, it is clear that the researchers have controlled for errors and known variability wherever possible and yet still they see an accelerating rise of sea levels.
3. The graph from the paper linked shows, for the 60-day smoothed line, a higher degree of sea level rise compared to the trend line for every year since 2015; i.e. sea levels are rising higher than the average trend since then. No comparable number of years since 1993 (this graph) show this.
Da Schneib
Fake link.
This crap makes it obvious that deniers are liars.
MR166
Bert_Halls
Da Schneib
MR166
Da Schneib
MR166
Da Schneib
SamB
Why is change always bad? We do not know if the change will be good or bad, so let us just see what transpires. Maybe this will be good for the world with a new North West passage, maybe better growing seasons, etc...
Shootist
let me know when they have done so for a century.
Ken_Fabian
There has been 3x more sea level rise in the past century than any century of the past 2000 years (some centuries it went up, some it went down). Not long enough yet to show the most recent accelerations from icesheet melt in sea levels as clearly distinguishable from internal variability (just regional flooding can shift water from sea to land and change sea levels between one year and the next).
https://www.aviso...vel.html
Thorium Boy
Thorium Boy
Shootist
https://www.franc...ate-jets
MR166
https://wattsupwi...-energy/
Da Schneib
Nice idea but it's gonna need work. Like most carbon-capture technologies do.
MR166
You really think so eh?
You would not recognize AGW bs if you stepped in it!
MR166
MR166
snoosebaum
ChucktheCanuck
"9.3.3 Accelerations in Sea Level Rise
Is there evidence of any "accelerations" (or departures from
long-term linear trends) in the rate of sea level rise7 From
examinations of both composite regional and global curves
and individual tide gauge records, there is no convincing
evidence of an acceleration in global sea level rise during
the twentieth century For longer periods, however, there is
weak evidence for an acceleration over the last 2-3
centuries"
Thorium Boy
Thorium Boy
Da Schneib
Got it.
zz5555
TheGhostofOtto1923
"The E-Cat (Energy Catalyzer) is a newly-developed heating technology with an extremely high power density that will provide industrial-grade heat at costs well below those of conventional heating sources. In a live online broadcast on January 31, 2019, the E-Cat's inventor, Dr. Andrea Rossi, will introduce the first commercial E-Cat product, show a demonstration of the technology, and answer questions from interested viewers."
-The ice is saved yay!
TheGhostofOtto1923
"Customers pay for heat delivered at costs that will always be significantly lower (at least 20 percent lower) than the cost of any other energy source the customer may use."
-When dr Mills's dark matter hydrino engine comes online, rossi will go broke.
MR166
TheGhostofOtto1923
TheGhostofOtto1923
Abstract
"Some theoretical frameworks that explore the possible formation of dense exotic electron clusters in E-Cat SK are presented. Some considerations on the probable role of Casimir, Aharonov-Bohm and vacuum polarization eects in the formation of such structures are proposed. Dense electron clusters are introduced as a probable precursor for the formation of proton-electron aggregates at pico-metric scale, stressing the importance of evaluating the plausibility of special electron-nucleon interactions, as already suggested in [14]. An observed isotopic dependence of a particular spectral line in the visible range of E-Cat plasma spectrum seems to conrm the presence of a specic proton-electron interaction at electron Compton wavelength scale..."
-although 'eects' is not a physical interaction that I'm aware of. More questions than answers Im afraid.
TheGhostofOtto1923
"In addition to its theoretical aspects, the paper describes an experiment conducted with the E-Cat SK, concluding that the COP of the E-Cat SK was:
"COP2 = Eout/E2 >107 (SSM)
"Definitely a huge value! After 60 days of continued operation an E-Cat SK has produced (as we can and from a simple extrapolation) 31680kWh of heat, approximately the equivalentof 2762 kg of heating oil (avoiding, at same time, the emission of about 800 kg of CO2)."
-With all that power, how can we not take him seriously? I mean, seriously? "800 kg of CO2" - of course Gore must be involved...
MR166
Ah the ghost of Professor Cory Irwin lives.
https://www.youtu...dRGbQPr0
TheGhostofOtto1923
howhot3
TheGhostofOtto1923
Etc.
Just glowing little boxes in everybody's basement and under car hoods, supplying endless power for next to nothing. Ships, trains, planes, starships. The only thing to worry about then, eventually, would be waste heat.
I do think rossi exposed his fraud during his last show when he lifted the corner of his black box and flipped a switch.
Dr Mills and his hydrino dark matter furnace still shows promise however.
TheGhostofOtto1923
howhot3
Maybe for a good SCI-FI movie, But first you need to demonstrate that Dark matter is something one can extract energy from. I've followed Rossi for a while in hopes it was the real deal, but alas, I'm not getting it. Hydrated metals do heat up in a pressurized hydrogen gas by what can be described as 'internal friction' as the metal 'breaths'. I don't see anything that will save the planet.
But keep your chin-up @Ghost, there could be some exciting renewables showing up soon.
TheGhostofOtto1923
Like this
https://brilliant...a-video/
-Is it real? Who knows? Could it be faked? Yeah, at the moment.
But I prefer to keep an open mind because its funner.
TheGhostofOtto1923
But I dont think his present facilities will be adequate for accommodating that sort of production. Maybe he has a backyard.
TheGhostofOtto1923