The demise of ice in New Zealand's Southern Alps

To say that articles like this,chronicling the demise of ice in New Zealand’s Southern Alps is ‘unusual’ would be a gross exagerration.

In the years I have been covering this I recall one piece of research on the Southern Alps written up in Australian media and one other comprehensive piece of journalism published in the New York Times (!)

New Zealand is busy bickering about petrol prices while the world burns

Stuff.co.nz,

10 October, 2018

OPINION: Earlier this year, I had the vaguely surreal experience of flying over the largely barren Southern Alps.

The usually snow-capped peaks were bare. Many of the small glaciers above the snowline were reduced to puddles. 

I was tagging along with NIWA's end of summer snow-line survey, which has been undertaken every year since 1977. The mountains had never been as bare as they were last summer - not even close. Lakes that didn't exist when the survey started are now several kilometres long. 

I reported more extensively about the decline of our glaciers a few months later, and spent a lot of time looking at old, sepia-tinged photos of Franz Josef glacier - a huge wall of ice, erupting up a valley - which bore no resemblance to the glacier now, a dwindling tongue covered in dirt, retracting out of sight.

THOMAS PRINGLE

The first photo of Franz Josef glacier, taken by Thomas Pringle in 1867.

READ MORE:

* Our barren Alps: Aerial survey shows snow loss 'incredibly extreme'
* Climate change and climate sceptics
* Southern Alps will likely save NZ from 'river piracy', but they won't save our retreating glaciers

Glaciers serve as a kind of thermometer for the climate. When temperatures are warm, they melt. When they're cold, they grow. With a few peculiar exceptions, it really is that simple. Ice melts in heat. 

I thought about our glaciers yesterday after the release of the IPCC's report into the possibility of limiting warming to 1.5C by the end of the century.

There are lots of reports about climate change and it's easy to become numb to them. This one, with 91 co-authors and reference to 6000 scientific papers, the most complete scientific consensus to date about limiting warming to 1.5C, was particularly bleak. 

It was bleak because it indulged the possibility of a best-case scenario. The report's co-chair, Jim Skea, said limiting warming to 1.5C was still "possible within the laws of chemistry and physics".

Translation: We can still, technically, do it. It's the laws of politics that may be a problem. 

ALDEN WILLIAMS/STUFF

Franz Josef glacier in 2018.

Within an hour of the IPCC report's release, the Prime Minister was talking about fossil fuels at her post-Cabinet press conference.

Jacinda Ardern wasn't talking about how to stop using them – which the IPCC report made abundantly clear needed to happen rapidly – but how to burn them more cheaply.

Purely from an optics perspective, it was weird timing. A prime minister who has spoken effusively on the world stage about the existential threat of climate change was, one hour after a global report urged a rapid phase-out of fossil fuels, scolding fuel companies for not selling their damaging product cheaply enough.

In the Prime Minister's defence, she wasn't specifically asked about the report. She was, however, asked to comment on refurbishments at Premier House, and the possums in its roof. The media, as ever, has a role to play here, too.

That this report was coming out was no secret. Journalists and policymakers have had access to it since at least Saturday, when it was approved. If there was one afternoon in which we shouldn't have been talking about how to burn more petrol, it was this one.

GEORGE HEARD/STUFF

The largely bare Southern Alps at the end of summer, 2018.

One of the reasons why climate change struggles to get traction in a political context is that it's experienced in abstract ways.

Most people have an immediate, first-hand experience of rising petrol prices - that's partly why it's an important issue the public is concerned about, and why politicians are always keen to be seen responding to it.

The Prime Minister's response, however, doesn't address the wider issue, which is our reliance on fossil fuels. The release of the IPCC report was an opportune time to confront this. Instead, the opposite happened.

The IPCC report makes it clear that the difference between 1.5C and 2C of warming would be immense, and is in everyone's best interest to achieve.

Under 1.5C of warming, between 70 and 90 per cent of coral reefs will die. Under 2C, virtually all coral reefs (more than 99 per cent) will be gone. Half a degree separates a world in which coral reefs exist and one in which they do not.

Under 2C, many millions more people will be exposed to coastal risks, and global damage from flooding related to sea-level rise could be more than $1t more each year.

If we don't limit warming, the seas will rise higher and more quickly - dramatically so, if the Antarctic ice-sheet melts. The vast majority of New Zealanders live on the coast, and we collectively have billions of dollars worth of assets in the lowest, most at-risk zone.

Some of our most threatened communities are poor, like those in South Dunedin or on the Buller coast. The extent to which we limit warming, and therefore sea-level rise, will affect where future generations of New Zealanders will be able to live.

New Zealand's economy is built on two things: Farming animals that burp methane, and bringing people here on planes that burn fossil fuels. De-carbonising the economy, a process which needs to happen extremely quickly, will affect everyone, but if it doesn't happen, the future costs could be much greater.

The Government is doing promising things in regards to climate change. The proposed Zero Carbon Act and the independent climate commission are a huge step forward, particularly if they come with a degree of cross-party consensus, which is starting to look likely.

The IPCC report was an ideal time to kick the tyres. The scale of the change needed across all aspects of society is unprecedented in all human history, and requires all countries to do everything possible.

If nothing else, it's an important message for leaders to communicate. The long-term costs of climate change will affect everyone, and the sacrifices we make now will change the future.

Instead, we were bickering about petrol prices while the world burns. 

Thin Ice

New Zealanders born today will live to see their country’s great glaciers shrink into extinction. No wonder there’s a boom in the number of people going to see them.

Like glaciers all over the world, the modern story of Franz Josef is one of decline. During the last ice age, it surged many kilometres further in a glistening wall of ice. By the time it was found and named by colonial settlers in the mid-19th century, it reached where the first viewing platform is today. Now, it is several kilometres further back, high up a valley, its tongue severed.

The irony is that although Franz Josef glacier is likely the smallest it has been for many thousands of years, it has never been in higher demand. Tourism has boomed to an unprecedented level, largely through a buoyant Chinese tourism industry - in the summer months, the entire town is booked out. The township must grow to meet that demand.

It risks, quite literally, building onto thin ice. The glacier will continue to shrink, likely at a rapid pace as the world gets warmer. Even if the world stopped polluting the climate today, the retreat would not stop, although it would probably slow. There will come a time where Franz Josef will no longer be spectacular, at least from ground level, and visitors will stop coming.

It's a long term threat to those who live and work in Glacier Country, the engine room of the West Coast economy which has spawned a multi-million dollar industry, employing hundreds of people. But for now, business is booming. The ice remains.

A few days earlier, ex-tropical cyclone Fehi had landed on the West Coast, destroying roads and flattening buildings in Glacier Country. But nevertheless, the path to Franz Josef glacier is packed. The car park is straining with rented campervans and tour buses, their colourful slogans popping in the grey valley.

After a 15-minute walk through the forest, the glacier first comes into view with a viewing platform hanging over the riverplain below. There are young families and tour groups and grandparents with their grandchildren, some from China, others from Germany, Australia, the USA. Two-hundred years ago, they would have been standing on the glacier but now it is a speck on the horizon, partly covered by a patch of low, dark cloud, unspooling down the ice.

Wolfgang Mueller, from Germany, last saw Franz Josef Glacier nearly 50 years ago.

An older German couple, Edeltraud and Wolfgang Mueller, have perched in a spot amongst the crowd.

Wolfgang was last here as a young man 48 years ago, he says, when the glacier roared down the valley, near where he is standing now.

It is much smaller now: “It looks completely different,” he says. “I expected that”.

Edeltraud, visiting for the first time, sees the withering glacier as a warning.

“Twenty or thirty years ago, we thought about climate change and everybody said ‘oh, you’re silly’,” she says.

“But now we have it, it’s right here.”

We know climate change influences massive storms and rising seas, acidifies the oceans and kills forests; we know it can increase the range of diseases, while reducing the range of rare species. But when we see those things, they can seem one step removed from the process of warming.

A glacier is useful because it is simple. The way it sheds ice in chunks and leaks meltwater through its tongue, how it slowly retracts into the mountains, taps into a basic truth that everyone knows: Ice melts in heat.

“I think they’re the most valuable measure of climate change,” says Dr Trevor Chinn, a glaciologist.

“Every single item to do with climate is fed into them.”

A glacier is effectively a frozen river, which starts when snow falls faster than it melts. As the snow piles up, it compresses into a thick slab of ice which becomes unsustainable, squeezing ice slowly through steep valleys. In person, a glacier looks static, but take a photo every hour and you see it is constantly moving, sometimes by a few metres every day.

If we did not have glaciers trapping the water in the skies, the oceans would be 60m higher, and many low-lying cities would not exist. During the last ice age, the glaciers held so much water that sea levels were more than 100m lower than they are today: Cook Strait would have been a land bridge, if anyone had been around to walk it, and glaciers completely covered the Southern Alps, effectively separating the west from the east.

The study of glaciers used to be obscure, but has entered a renaissance period. By looking at one glacier, a scientist can begin to understand the climate it exists within and make projections about the future, which has stark implications for monitoring climate change.

This is particularly apparent in New Zealand, which is one of the best places in the world to study glaciers and climate. Our best-known glaciers are steep, accessible, and warm, due to the maritime climate of a land surrounded by ocean, which makes them susceptible to minor temperature changes.

“The ice in the glacier is only just below zero degrees, so if you think about that, you don’t have to change temperature very much to bring it up to melting,” says Dr Heather Purdie, a glaciologist at the University of Canterbury.

“And [glaciers] are not just measuring temperature, they’re measuring precipitation, snow, cloudiness - all these other general climate parameters are homogenised into the glacier, and it’s providing an average picture of regional climate for the area that it’s in.

“If we kind of watch what they’re doing, we can see what’s happening. They’re a really good independent measurement of climate.”

For a brief period, Franz Josef had a lake at its terminus.

It used to be that a glacial pace, in common usage, was synonymous with slowness. Today, a glacial pace is quick and unpredictable; ice that formed over thousands of years can dissolve and vanish over decades.

In New Zealand, this effect has been most obvious at Franz Josef and Fox glaciers on the West Coast, which are steep, accessible, and acutely sensitive to temperature changes.

Even among the world’s many glaciers, Franz and Fox are extraordinary, because of how closely they follow the climate. All glaciers have a “response time”, which is how long it takes for the glacier to respond to temperature changes.

For many large glaciers, it’s a couple of decades; larger glaciers can have response times as long as a century. These glaciers are still in the climate of the past, slowly catching up with the polluted climate of the present.

Franz Josef and Fox, due to their size and their maritime climate, have smaller response times. Franz’s is only three or four years, and Fox’s is five or six years, which means we can see how they’re being affected by today’s climate.

By following the shifts in the glacier, we can see what the slow burning climate signals are unable to tell us: What we are doing right now is transforming the natural world, which is changing right in front of us.

It first appeared as a small, black mark in the early 2000s after heavy rain, and has grown to become a glaring blot on the glacier.

When the ice flow reaches the black hole, it splits into two streams, cascading down each side before rejoining as one to flow down the tongue.

Its name has a fitting quality for a retreating glacier; the ice retracts further up the valley, as if being sucked into the black hole.

Within the next few decades, it is likely the glacier will end somewhere around the black hole, which is above where most of the glacier walks are done today. Projections for the glacier’s retreat in the future differ, and largely depend on the extent of warming, but it’s expected much of Franz Josef’s tongue will be gone by the end of the century.

By then, the glacier will be all but unrecognisable.

The first photograph of Franz Josef, taken around 1870, shows an enormous, jagged wall of ice thundering down the valley, nearly as tall as the surrounding mountains. Stand in the same spot today, and you see very little; the ice has thinned by many hundreds of metres and curled around a corner.

Franz Josef retreated drastically throughout the 20th century, as temperatures slowly started to warm. It lost about 3km of its length in total, exposing the gorge and the river flowing beneath for the first time in many centuries.

While the retreat in the 20th century was significant, it hit a higher gear around 2008. In just a decade, it has lost another 1.4km of its length, the fastest rate of retreat ever recorded at the glacier.

The result is that the glacier is likely the smallest it has been in a very long time. There is preliminary work which shows that very little of the rock at the front of the glacier has been exposed to the atmosphere before, meaning those studying it are the first humans to set foot there, on land that for millennia was buried deep in the ice.

From a ledge high above Franz Josef, Dr Brian Anderson, a glaciologist at Victoria University, looks down at the steep, ice-carved valley below.

Until recently, the gorge had been covered in ice, concealing everything beneath. Plants are now starting to grow where the glacier once filled the valley, which have left a shadow along the walls, marking where the glacier used to be.

“I’d never seen this gorge until the last decade, so I never knew what was under here,” Anderson says.

When he was growing up on the West Coast, Anderson spent a lot of time in the mountains. For much of his life, the glaciers were advancing, growing in response to a localised cooling period that lasted throughout the 1980s and 1990s, a period of growth that was both spectacular and unique.

When he started studying Franz Josef as a glaciologist, he visited every month for 12 years to measure stakes he had drilled into the ice, to see how far the glacier had moved.

It was an old-school style of glaciology, he says, similar to how the glacier was measured earlier in the century - on one trip, whilst scrambling around the forest, he found several of the stakes used to measure the glacier many decades earlier, which had since been forgotten in the forest that grew in the glacier’s wake.

When Anderson wrote his thesis about Franz Josef in the early 2000s, he projected a sharp retreat in the coming years, in response to the warming climate. When the retreat began in earnest in 2008, even he was surprised at how quickly the glacier started disappearing.

“It’s faster than I thought it could possibly retreat, to be honest, and it’s the fastest in the historic record,” he says.

He has started using more modern tools to chronicle the glacier’s movements. He has a network of nine strategically placed cameras taking photos every hour, which he stitches together into timelapses. They are in obscure spots off the beaten track so they won’t be disturbed, and lodged in boxes, mostly to protect them from kea. He has lost two cameras to lightning strikes, but the rest have survived, feeding a collection of what is now 100,000 photos.

One of his time lapses shows a year of retreat at Fox Glacier in 2012, in which a large chunk of its tongue collapsed. It went viral, because it was a stark illustration of how dramatically a glacier can change in a remarkably small period of time.

“I see all these things that I didn’t really realise were changing," he says.

"Basically, everything’s moving, everything’s coming downhill, there are little rockfalls everywhere, it’ll rain a lot and it’ll flood and masses of ice will fall off the glacier, just all these things you wouldn’t necessarily notice just by visiting.”

His latest findings show something quite extraordinary: Franz Josef is advancing. Since the end of 2016, it has crept forward by about 80m, which would make it one of the few glaciers in the world that is growing, not shrinking.

It’s not much, Anderson says - an 80m advance after a 1400m retreat is one step forward after 18 steps backwards - and he has no doubt it will retreat again. Already, after a historically warm summer, the glacier appears to be leaking, with a large hole spurting water that wasn’t there last year.

But it’s a rare glimmer of hope in a field that may one day become redundant, once the glaciers are all but gone.

“How many advancing glaciers are there in the world that you can go and visit?” he says.

“It’s probably only a handful.”

He pauses as a helicopter passes overhead, the deafening sound of its rotors filling the empty space of the gorge, dropping off another load of tourists onto the ice, tiny black dots against the sprawling white ice.

Anderson is not hopeful that emissions can be curbed to keep the glacier looking like it does now; more retreat is inevitable.

It has already happened so quickly he can see the retreat through his own children. He walked onto the glacier with his first child, but not with his second. By then it was too late.

But right now, for a brief moment, the glacier is growing, and it still looks spectacular.

“It’s really special that the glacier’s advancing at the moment,” he says.

“It’s probably not going to do it for very long, just because it’s so warm. But even though the big picture is one of retreat and a really obvious human cause for that, I think we also have to apprciate what we have, which is still really special.”