"When you look at several decades, it is best to sit back in your chair before looking at the results, because it is a bit scary to see how fast it is changing," French glaciologist Eric Rignot, of the University of California at Irvine
Abrupt! Climate! Emergency!
I was perusing my climate news feeds this morning and recoiled, yet again, in horror at another report on the human impacts from the climate crisis.
Example A; entire villages in India have been evacuated due to lethal heatwaves and extreme drought. Only the sick and elderly were left behind.
The climate crisis is so apparent and dangerous currently that you would have to have your head in the sand to believe otherwise.
Example B; One of the more dramatic impacts so far this year in the United States have been the constant rainfall in the middle west and southeastern states.
Farmers and small rural towns marvel at the destructive impacts on agriculture. Swamped flooded fields along with stinging tariffs, that their hero Donald Trump unleashed on them, have some farmers facing financial ruin. As the crisis continues to unfold our food supply is threatened.
The irreversible loss of critical topsoil along with industrial fertilizers now funnel into the Gulf of Mexico via the flooded Arkansas, Missouri and Mississippi rivers. The fertilizers are expected to create a dead zone the size of Massachusetts.
Why I mention these two examples of damage from a rapidly heating world is to emphasize that what happens in the Arctic does not stay in the Arctic. And what is happening in the Arctic today is grim, the consequences for all will be dire if the world does not get moving to act on the scale that this cataclysmic haunting requires.
All of us should brace ourselves for the remainder of 2019. The loss of most of Greenland's reflectability, as well as the albedo feedback loop, promises to be a bare ass spanking on a global scale.
Greenland lost 2 billion tons of ice yesterday, which is very unusual
Over 40% of Greenland experienced melting yesterday, with total ice loss estimated to be more than 2 gigatons (a gigaton is equal to 1 billion tons).
While Greenland is a big island filled with lots of ice, it is highly unusual for that much ice to be lost in the middle of June. The average "melt season" for Greenland runs from June to August, with the bulk of the melting occurring in July.
To visualize how much ice that is, imagine filling the National Mall in Washington DC with enough ice to reach a point in the sky eight times higher than the Washington Monument (to borrow an analogy Meredith Nettles from Columbia University gave to the Washington Post.)
A persistent weather pattern has been setting the stage for the current spike in melting, according to Mote.
"We've had a blocking ridge that has been anchored over East Greenland throughout much of the spring, which led to some melting activity in April -- and that pattern has persisted."
That high pressure ridge pulls up warm, humid air from the Central Atlantic into portions of Greenland,.which leads to warmer temperatures over the ice. The high pressure also prevents precipitation from forming and leads to clear, sunny skies.
Over the past week or two, that high pressure ridge got even stronger as another high pressure front moved in from the eastern United States -- the one that caused the prolonged hot and dry period in the Southeast earlier this month.
The Guardian has a much-read piece (includes raw drone footage) on the loss of sea ice in the Arctic.
“Less oxygen and ice, more acid and heat. Jonathan Watts joins an expedition studying what this means for the planet”.
The demise of an entire ocean is almost too enormous to grasp, but as the expedition sails deeper into the Arctic, the colossal processes of breakdown are increasingly evident.
The first fragment of ice appears off the starboard bow a few miles before the 79th parallel in the Fram Strait, which lies between Greenland and the Norwegian archipelago of Svalbard. The solitary floe is soon followed by another, then another, then clusters, then swarms, then entire fields of white crazy paving that stretch to the horizon.
From deck level it is a stunning sight. But from high above, drones and helicopters capture the bigger, more alarming picture: a slow-motion blast pattern of frozen shrapnel radiating from the high Arctic southwards through this strait, which is the interchange of 80% of the water between the ice cap and the world’s oceans.
This is where ice floes come to die, and the cemetery is filling faster each year, according to the leader of this scientific expedition, Till Wagner, of the University of North Carolina Wilmington (UNCW). One of the objectives of the expedition is to investigate why the collapse of Arctic ice is happening faster than climate computer models predict and to understand what this augurs for the rest of the planet.
An important video in understanding the early melt season on Greenland this year. The video immediately below is narrated by one of my heroes, Jason Box.
This busy diary continues below the fold with lots of glacier porn.
An image of a rift on Petermann Glacier taken directly beneath the Operation IceBridge aircraft.
The Geological Society of Denmark and Greenland has found that iceberg calving has increased
A new study led by The Geological Survey of Denmark and Greenland (GEUS) and published with Earth Systems Science Data estimates the ice discharge -transfer of land-ice into the ocean, at 276 tidewater glaciers around the Greenland Ice Sheet between 1986 and 2017. This makes it the densest sampling of the ice sheet’s tidewater glaciers to date.
The ice-sheet-wide discharge or iceberg calving is estimated to have increased from less than 450 Gt/year in the 1980s and 1990s to closer to 500 Gt/year now. That increase of 50 Gt/year is equivalent to an extra 1600 tons per second of icebergs year-round relative to the 1980s and 1990s.
From CIRES:
In August 2012, in the frigid wilderness of West Greenland, the Jakobshavn Glacier was flowing and breaking off into the sea at record speeds, three times faster than in previous years. An underwater calving event had caused the massive glacier to lose its footing. But the movement was not linear like a runaway train (as previous studies suggested), but dynamic: drastically speeding up, then slowing down after a few days.
Now, a new assessment by a multi-institutional, CIRES-led team has harnessed a novel, highly detailed dataset to identify the factors that caused the speedup and slowdown. As the glacier flowed faster, it became thinner and more unstable—and then, in a twist, a pileup of thick ice replenished the glacier’s terminus, slowing it down again. The work, published today in the Journal of Glaciology, may help scientists better predict how tidewater glaciers contribute to sea level rise.
“As tidewater glaciers, like Jakobshavn Isbræ, thin they become increasingly sensitive to small variations in ice thickness,” said Ryan Cassotto, CIRES researcher and lead author of the new study, which was conducted while he was a doctoral student at the University of New Hampshire. “This is because water pressure at the base of the glacier counters pressure from the weight of ice above it, which impacts how fast the glacier flows.” For tidewater glaciers grounded deep below sea level, thicker, heavier ice travels slower, and thinner, lighter ice, faster. It’s similar, Cassotto said, to the way different sized cars hydroplane: large, heavy truck tend to be very stable and resist sliding while lightweight, compact cars readily slip.”
A fascinating video that illustrates how much ice is under the waterline.
From Science Magazine:
Why slow glaciers can sometimes surge as fast as a speeding train—wiping out people in their path
Most surges, broadly defined as a flow at least 10 and often hundreds of times faster than a glacier's usual pace of advance, are quieter affairs. Many are imperceptibly slow, but others attain staggering speeds. In 1953, for example, Kutiah Glacier in Pakistan advanced 12 kilometers over 3 months. Besides overwhelming settlements, glacier surges can threaten distant communities. They can block rivers, creating lakes that can later unleash floods, and by depleting glacier mass, they can threaten the flow of meltwater that downstream towns and farms may depend on.
Now, by studying glaciers from Tibet to the Arctic islands of the Svalbard archipelago in Norway, researchers are starting to understand why some glaciers swing between extremes of stagnation and crushing flow, and how surges may be predicted. Until recently, most glaciologists believed that a glacier's physical characteristics, such as its thickness and shape, and the properties of the terrain it sits on determine whether it can surge. Now, they believe an external factor also plays a major role: water from precipitation and melting. Pooling on the surface, it can infiltrate the glacier through crevasses and reach its base, warming, lubricating, and, ultimately, releasing the ice.
snip
As the researchers reported in 2015 in The Cryosphere, Austfonna's movement accelerated each year in early July and slowed in late August. Faster speeds broadly correlated with the number of days of above-freezing air temperatures. But year after year, after the glacier slowed in August, its movement was faster than it had been before the speedup. "It got pushed to a higher level every summer," Schuler says. At the same time, its crevasses were deepening and extending. Suddenly, in the autumn of 2012, the glacier failed spectacularly. Over the following months, it gushed 4.2 cubic kilometers of ice—enough to fill 1.7 million Olympic-size swimming pools—into the Barents Sea. "It was the surge of the century," Schuler says.
Based on the correlation between warming and speedup, Schuler and his colleagues suspect that the trigger for the surge was meltwater that trickled down through crevasses and accumulated at the glacier's base, summer after summer. As the infiltrating water froze, the latent heat it released warmed the surrounding ice. "This alone can change glacier dynamics quite drastically" because warm ice flows a lot faster than its subzero counterpart, Schuler says. And as more water accumulated beneath Austfonna, the increasing pressure, like a hydraulic jack, lifted the glacier from its bed.
Ultimately the cold ice anchoring Austfonna's tongue to the ground disintegrated. "That was the critical part that held the ice back," says Jon Ove Hagen, a UiO glaciologist. Its loss unleashed the surge.
The perfect metaphor for the climate crisis.