Antarctica Is Melting, and Giant Ice Cracks Are Just the Start

GR: Glaciers are melting at the North Pole, the South Pole, and in mountains around the planet. Sea level is rising. If we stop adding greenhouse gasses to the atmosphere now, melting might stop within a few centuries. At that point, sea level will be more than 30 feet higher than it is now. If we continue to add greenhouse gasses to the atmosphere, we can expect 70 feet of sea-level rise before stability is reached. Stability at that point will occur because we will have stopped producing greenhouse gases–we will have little working technology left. Cutting emissions immediately is the only way we might limit the rise to 30 feet.

In East Antarctica, Australian researchers probe for crevasses on Totten Glacier—another one that has begun to look vulnerable—before deploying instruments to measure how fast it’s moving and thinning (photo by Camille Seaman).

As you will see as you read this article, critical measurements are underway to determine how fast the ice is melting. It is expensive to make the measurements that will give us the ability to predict and plan for rising sea level. Less money than presidential trips to Florida to play golf, but substantial amounts nevertheless. This is just the type of necessary spending the Trump administration (actually the corporatists controlling Congress) is intent on ending. Isn’t this a crime against nature and humanity?

Melting Antarctic Glaciers

(The following story appears in the July 2017 issue of National Geographic Magazine.)

“The massive iceberg poised to break off the Larsen C Ice Shelf may be a harbinger of a continent-wide collapse that would swamp coastal cities around the world.

“Seen from above, the Pine Island Ice Shelf is a slow-motion train wreck. Its buckled surface is scarred by thousands of large crevasses. Its edges are shredded by rifts a quarter mile across. In 2015 and 2016 a 225-square-mile chunk of it broke off the end and drifted away on the Amundsen Sea. The water there has warmed by more than a degree Fahrenheit over the past few decades, and the rate at which ice is melting and calving has quadrupled.

“On the Antarctic Peninsula, the warming has been far greater—nearly five degrees on average. That’s why a Delaware-size iceberg is poised to break off the Larsen C Ice Shelf and why smaller ice shelves on the peninsula have long since disintegrated entirely into the waters of the Weddell Sea. But around the Amundsen Sea, a thousand miles to the southwest on the Pacific coast of Antarctica, the glaciers are far larger and the stakes far higher. They affect the entire planet.

A startling sunset reddens the Lemaire Channel, off the west coast of the Antarctic Peninsula. The continent’s coastal ice is crumbling as the sea and air around it warm (photo by Camille Seaman).

 

“These are the fastest retreating glaciers on the face of the Earth,” says Eric Rignot, a glaciologist at the NASA Jet Propulsion Laboratory in Pasadena, California. Rignot has studied the region for more than two decades, using radar from aircraft and satellites, and he believes the collapse of the West Antarctic Ice Sheet is only a matter of time. The question is whether it will take 500 years or fewer than a hundred—and whether humanity will have time to prepare.

“We have to get these numbers right,” Rignot says. “But we have to be careful not to waste too much time doing that.”

“Getting the predictions right requires measurements that can be made only by going to the ice. In December 2012 a red-and-white Twin Otter plane skimmed low over the Pine Island Ice Shelf. The pilot dragged the plane’s skis through the snow, then lifted off and circled back to make sure he hadn’t uncovered any crevasses. After the plane landed, a single person disembarked. Tethered to the plane by a rope and harness, he probed the snow with an eight-foot rod.” –Douglas Fox–Photographs by Camille Seaman. (This story appears in the July 2017 issue of National Geographic magazine. Continue: Antarctica Is Melting, and Giant Ice Cracks Are Just the Start.)

The west side of the Antarctic Peninsula is warming several times faster than the rest of the planet. Ninety percent of its 674 glaciers are now in retreat and are calving more icebergs into the sea, like this one in Andvord Bay (photo by Camille Seaman).

Worrisome first quarter of 2017 climate trends – Yale Climate Connections

GR: Here’s a handy summary of global temperature, sea ice, and coral reef changes so far in 2017.

“With the first quarter of 2017 now past, the year is shaping up to be one of climate extremes: high temperatures, low sea ice, and coral bleaching.

“The year is shaping up to be one of #climate extremes: high temps, low sea ice, and coral bleaching.”

“Global surface temperatures continue to increase in-line with climate model predictions, and the world has now experienced an increased global temperature of about 0.8 degrees C (1.5 degrees F) since 1970. Temperatures for the first three months of the year were actually warmer than the 2016 average, and there is a reasonable chance that 2017 for a fourth consecutive year will be the warmest on record.

“Global sea ice extent is near historic lows in the Arctic and Antarctic, and Arctic sea ice volume has also been decreasing as it ages and thins, with less new ice to replace it. The Great Barrier Reef experienced an unprecedented second consecutive year of coral bleaching, the only major coral bleaching on record to have occurred other than in an El Niño year.

Temperature

“Global surface temperatures were surprisingly warm in the first quarter of 2017. Despite the end of the large 2015/2016 El Niño, temperatures remained high with January, February, and March each being the second warmest on record, after 2016.” –Zeke Hausfather (Continue reading: Worrisome first quarter of 2017 climate trends – Yale Climate Connections).

An Armada of Icebergs Has Just Invaded The North Atlantic

GR: Swarms of icebergs are another symptom of global warming that we meet as we cross the threshold of accelerated change. RobertScribbler reports on the complex connections and dangers in many posts. Here’s a sample.

“I have about a decade of experience with the Ice Patrol, and in my time here, and talking with people who have been here longer, I’ve never seen anything like this or heard of anything like this before,” — Gabrielle McGrath, Coast Guard Commander of the US Ice Patrol.

“A Heinrich event is a phenomenon in which large armadas of icebergs break off from glaciers and traverse the North Atlantic.” — Commons

“Consider the situation during past ice sheet disintegrations. In melt-water pulse 1A, about 14,000 years ago, sea level rose about 20 meters in approximately 400 years (Kienast et al., 2003). That is an average of 1 meter of sea level rise every 20 years.” — Dr. James Hansen.

“This week an unprecedented 481 icebergs swarmed into the shipping lanes of a storm-tossed North Atlantic. Strong hurricane force winds had ripped these bergs from their sea ice moored haven of Baffin Bay and thrust them into the ocean waters off Newfoundland. The week before, there were only 37 such icebergs in the Atlantic’s far northern waters. And the new number this week is nearly 6 times the annual average for this time of year at 83. To be very clear, there is no record, at present, of such a large surge of icebergs entering these waters in so short a period at any time in the modern reckoning.

(Many glaciers along the periphery of Greenland have passed the point of no return. In other words, at present temperatures, these glaciers will completely melt. In the past, such major melting events have released ‘armadas of icebergs’ into the North Atlantic in instances called Heinrich Events. Video source: Chasing Ice.)

Likely Precursor to a Heinrich Event

–RobertScribbler (Continue reading: An Armada of Icebergs Has Just Invaded The North Atlantic | robertscribbler.)

This week, a massive swarm of icebergs that calved from Greenland and entered Baffin Bay have been kicked into the North Atlantic by a powerful storm system. To be clear, this is the kind of thing you’d expect at the start of a Heinrich Event. Image source: U.S. Coastguard.

Antarctic Sea Ice Hits New All-Time Record Low | robertscribbler

GR:  Here’s an update on climate-change developments in Antarctica. As in the Arctic, sea ice is melting. Losing sea ice increases solar heat absorption by open water and changes pressure systems. If this accelerates as it has at the North Pole, we have one more factor contributing to wildfires, weather extremes, and impacts on wild plants and animals.

“During late February, Antarctic sea ice breached the previous all-time record low for extent coverage since measurements began in 1978. And in the following days, sea ice extent measures near the South Pole have continued to creep lower, gradually extending into unprecedented ranges.

More above average temperatures predicted this week for Antarctica may extend sea ice record lows somewhat before refreeze sets in. Image source: Climate Reanalyzer.

“Hitherto unseen global heat — driven primarily by human fossil fuel emissions — appears to be the chief contributor to this melting. During 2016, global average surface temperatures rose to 1.2 degrees Celsius above 1880s ranges. This global reading likely represents the warmest surface temperatures the world has experienced in the last 115,000 years. At the same time, the global ocean system has been rapidly accumulating warmth and transferring it through the surface and deep layers of the world’s waters.

“Such pervasive heat is producing an ongoing trend of considerable sea ice melt in the Arctic — a trend that has been in place since record-keeping began in 1978. One that, all by itself, is strong enough to drag global sea ice measures lower and lower. The warmth is also producing land ice melt around the world — including glaciers in Antarctica, Greenland and across numerous mountain ranges.” –Robert Scribbler (Continue reading:  Antarctic Sea Ice Hits New All-Time Record Low | robertscribbler.)

Global warming produced an identifiable global sea ice melt trend during the post year 2000 period. By 2016, that trend had become glaringly obvious. See final paragraph for further discussion. Image source: Wipneus.