‘Sliding through our fingers’: New Zealand scientists are outraged by the extent of glacier loss

The plane's engine groans and its small frame rises. Through a thin membrane of cloud, the spine of the Southern Alps rises like a dark saw blade.

“I wonder if my favorite glacier will be there,” said lead climate scientist Dr Andrew Lorrey. “We've had a really, really hot summer. It's hard to say. We'll just see how they've gone.”

‘It's going so fast': The decline of New Zealand's glaciers – video

In the pre-dawn darkness of Sunday morning, the small group of six researchers had gathered on the tarmac of a small airfield in Queenstown, packing cameras into backpacks, when a color leaked over the mountains. For most of the next eight hours they sat twisted in their seats, spines convulsing, lenses trained on the windows to catch the peaks of the Southern Alps as they emerged from the cloud cover. This is New Zealand's annual snowline survey, a single annual charter flight run by climate research institute Niwa that tries to capture the state of the country's glaciers before winter sets in. Today, after two record hot years, scientists are preparing for the worst.

As the small plane circles the peaks, the pilot flips between different maps on a tablet and compares notes with the science team through a headset to try to track the exact location of glaciers through the cloud cover.

Out the far window the blue-gray expanse of the Brewster Glacier looms to the right. The larger glaciers, such as Fox and Franz Josef, have shrunk but still meet you as huge rivers of ice, crinkled and cracked by the pressure of their descent, a thick ribbon of wrinkled pale blue crepe. In others, however, veins of dark rock grow out and eat deeper and deeper into the pale centers of the glaciers. Brewster's layer of ice looks like a slab of quartz, rippled with thin ribs of black dyke and apricot sediment. The thick snow and ice that might have once covered it has retreated, replaced with the dark sheen of newly exposed rock.

“It's really dramatic,” says Prof Andrew Mackintosh, the exhibition's lead researcher, leaning back over his headrest to shout over the roar of the engine. “I wouldn't have imagined seeing such changes in my lifetime – it's quite profound.”

Brewster Glacier, New Zealand.
Brewster Glacier, New Zealand. Scientists say it “won't be with us much longer”. Photo: Niwa / Rebekah Parsons-King

Mackintosh, a glaciologist now based at Monash University in Australia, helped start the monitoring program at Brewster Glacier in New Zealand in 2004. At the time, it was thick and healthy. “It's 20 years later, and I just wonder how …” he ends. “It will take a while to completely waste away, but it no longer has the characteristics of a happy, living glacier. It looks like something that's just decaying, and won't be with us much longer. “

A confrontational view

There is a sadness in watching the ice melt. Some of these scientists have been monitoring these glaciers for decades and return every year to take their pictures. They know each one by name and have their personal favorites. Some of the glaciers they used to record have disappeared in the past decade. Mackintosh and Lorrey occasionally lean over their gray vinyl seats to exchange observations, peering out the shivering windows. “She looks like shit,” says one of them.

“It's interesting as a scientist and a bit challenging as a human being to see that change,” says Mackintosh. “There is a kind of conflict: of fascination with how the system can change so quickly, combined with the emotional response of seeing the loss of ice that is such an important part of the landscape, and so beautiful and so culturally important.”

Brewster Glacier changes over three decades.  New Zealand.
Brewster Glacier has shrunk over two decades so that it no longer has “the characteristics of a happy, living glacier anymore”. Photo: Niwa / Rebekah Parsons-King

“The extent of retreat is confronting, even for a glaciologist.”

During the winter, the snow should cover the glaciers and slopes with a thick, smooth slab of marzipan. That snow feeds and protects the glacier, increasing the volume of the ice before the warmer months can remove it. Typically, a glacier will collect snow on top and slowly melt from its lower reaches, forming alpine lakes and ponds and feeding the braided rivers below. But the extent of warming temperatures is changing that dynamic even at high elevations, causing the ice on glaciers like Brewster to contract even at the higher reaches. “This is a glacier that's melting everywhere — on top and bottom and on the sides, just to get it all in,” says Mackintosh.

As the seasonal climate warms in the spring and through the summer, that snowline scales up. As the plane circles the back of Mount Bryant, Lorrey points out where the snow has retreated from the ice. “You see that ice here? All the bluish ice is completely bare, it's stripped. … So the whole glacier, almost 80%, 90% of it is melting. Every time you see blue ice, it's bare,” he says.

He shakes his head slightly. “That thing is emaciated.”

AAs the plane comes in to land at the Lake Tekapo airstrip, Lorrey points out the folds and drainage channels of the plains. “18,000 years ago, this whole valley was filled with ice,” he says. But if the ice's movement was once measured over hundreds or thousands of years, it now moves much faster, retreating from rising temperatures over the course of years or decades. 2022 was New Zealand's hottest year on record – the second consecutive year the record was broken.

Carrington Glacier, New Zealand.
Carrington Glacier, New Zealand. Dr Andrew Lorrey says urgent action is needed to save the country's remaining glaciers. Photo: Niwa / Rebekah Parsons-King

The flight attempts to document the snow lines of more than 50 glaciers, some of which have been monitored like this for the past 46 years. But over time some of the index glaciers have been replaced as they disappeared, replaced by cousins ​​in the higher reaches. Now even some of these replacement options are looking thin, and Niwa predicts that many of New Zealand's key glaciers will be gone within the decade.

There is still hope for the glaciers that remain, says Lorrey. A few fractions of a degree of warming is the difference between New Zealand's glaciers holding on or disappearing entirely.

“Rapid change is needed, rapid action is needed to change the path we are on,” Lorrey said. The damage can be done quickly, but the repair takes much longer. “These sudden and absolutely fast [losses] could happen in a few shockingly warm years,” he says, “but it's a glacially slow process to replenish that ice and build it up to its full glory.”

Fox Glacier, New Zealand.
Fox Glacier, New Zealand. Ice movement was once measured in hundreds or thousands of years – now it is years or decades. Photo: Niwa / Rebekah Parsons-King
The scientists on board the Niwa flight all have their personal favorites among the glaciers.
The scientists on board the Niwa flight all have their personal favorites among the glaciers. Photo: Niwa / Rebekah Parsons-King

“We know what's driving the loss of glaciers,” says Lorrey. “We know it exists an intimate connection between temperature changes and the changes we see in our glaciers. … We know that path is largely dictated by CO2 emissions.”

“It's kind of emotional to see a great, untouched part of our natural environment slipping through our fingers. I'd like to share it with my family and my friends and especially my daughters, and I don't know if I'll get that opportunity.. . It goes so fast.

“We need to confront this in a much more direct way, in a faster way.”

In the end, Lorrey's favourite, Llawrenny Peaks, was impossible to document this year – shrouded in thick cloud, impossible to see from the plane's window.

“In a way, I'm quite happy,” he says. “Because I suspect I might have cried if it wasn't there.

#Sliding #fingers #Zealand #scientists #outraged #extent #glacier #loss

Source link

Leave a Reply