Lethal Heating: 07/14/17

14/07/2017

'The Island Is Being Eaten': How Climate Change Is Threatening The Torres Strait

The Guardian - Ben Doherty | Michael Slezak

In Boigu, part of Australia but just six kilometres from Papua New Guinea, roads are being washed into the sea

Joseph Billy says his community is losing land to climate change every year. Photograph: Brian Cassey/Oxfam Australia

Torres Strait residents face being forced from their homes by climate change, as their islands are lost to rising seas.
On Boigu Island, the most northerly inhabited island in Australia, just six kilometres from Papua New Guinea, the community's cemetery faces inundation and roads are being washed into the sea. A seawall installed to protect the community is already failing.

Boigu elder Dennis Gibuma says the situation is worsening every season.

Every year I have moved my shed back from the beach another few metres.
Fisherman Joseph Billy

"Our seawall is no longer any good," he says. "When the high tide and strong winds come together, it breaks. We pray we don't lose our homes. We don't want to leave this place."
Masig Island, to the south-east of Boigu, is less than three kilometres long, and just 800m across at its widest point. Also known as Yorke Island, the low-lying coral cay is steadily being lost to the waves.
"The island is being eaten," says Songhi Billy, an engineering officer on Masig. "This is a big issue. I kind of feel hopeless in a sense. Our land is part of us.
"In the short term, we can do what we can. We can't stop the erosion, our hope is to slow it down."
But he says he has to face the possibility that his people may have to abandon their ancestral home.
"Long term, we may have to evacuate the island," he says. "But I am not going. Slowly, I see Masig Island getting out of something I can control."
Fisherman Joseph Billy says his community is losing land every year.
"Last five year, every year, I have moved my shed back from the beach another few metres. We used to have a road that went all around the island but now it is broken. We will lose our land eventually."
Sea levels around the world are expected to rise between 75cm and 1.5m by the end of the century, depending on greenhouse gas emissions. According to the Australian Department of Environment and Energy, a rise of just 50cm would increase the risk of flooding around Australia by 300 times – making a once a century flood likely to occur several times a year. In some areas of Australia, flooding risk would rise much more – up to 10,000 times.
The precise sea level rise around the Torres Strait, and the projected inundation, has not been calculated but low-lying islands are expected to experience a much greater flooding risk than mainland Australia. The department identifies the remote islands of the Torres Strait as some of the most vulnerable, as does the Intergovernmental Panel on Climate Change (IPCC), which warns communities they may be forced to relocate.

Boigu Island, where the community's cemetery faces inundation and a seawall installed to protect the community is already failing. Photograph: Brian Cassey/Oxfam Australia

The chief executive of Oxfam Australia, Helen Szoke, who visited the Torres Strait at the invitation of the Torres council mayor, Vonda Malone, says the people of the strait have contributed almost nothing to the causes of climate change but are being "hit first and hardest by its impacts".
"The islands face a combination of risks including coastal erosion and inundation from rising seas, damage to the critical marine ecosystems on which their livelihoods depend, higher temperatures and shifting rainfall. Roads are being washed away and seawalls cannot protect communities from flooding."
The "strong, flourishing communities" of the Torres Strait have a powerful connection to their land and sea country, Szoke says.
"The gravest fear among community members is the loss of their connection to land and culture if they are faced with the last resort – being forced to leave their islands. The longer-term challenges, including the threat of eventually being forced from their land, are complex and extremely confronting for communities with such a deep connection to their islands."

We have been advocating for years but it just does not seem to get enough attention.
Vonda Malone, Torres Strait mayor

Malone says leaving the islands is a last resort and the people of the Torres Strait want to do everything possible to remain.
"These communities are facing ongoing challenges in retaining their foreshore and their gathering places – this is their land and the land of their ancestors. These communities are seeing their land washed away. We have been advocating for years but it just does not seem to get enough attention."
Malone says while some funding for climate change adaptation is filtering through, there were few resources to address the social impacts of potential dislocation.
"There is a feeling of hopelessness as communities do not know where this is going to lead to," Malone says.
Displacement caused by climate change is forecast to be a driver of massive forced migration movements in the 21st century.
Low-lying islands in the Pacific – and Torres Strait islands like Masig and Boigu – are likely to be at the forefront of forced displacement but large and densely populated countries such as Bangladesh also face widespread inundation.
Some forecasts have predicted up to 150 million people could be forcibly displaced by climate change by 2040 – larger than the record number of people already forced from their homes globally.
The US and other militaries have said that climate change poses the greatest security threat to the Asia-Pacific.
But the global legal framework for resettling people displaced from their homes lost to natural disasters or climate change is unclear. The refugee convention – established in 1951 to regularise the resettlement of those displaced by the second world war – does not recognise someone forced from their home by rising seas, or natural disaster, as requiring protection.
Already, more than a dozen Pacific Islanders have attempted to claim refugee status in New Zealand on the grounds that their homes are uninhabitable because of rising seas or climate-related disaster. All have had their claims rejected.
On Masig Island, Hilda Mosby says climate change is already affecting the marine ecosystems on which communities depend for their livelihoods. Climate change is already affecting her community "big time", she says.
But the greater existential threat for her home lies ahead.
"When we talk about relocation, it is clear this is very much a last resort," Mosby says. "This is our home. No one is willing to leave, to lose their cultural ties, the loved ones they have laid to rest here. We want to try everything to keep our community here."

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I’ve Studied Larsen C And Its Giant Iceberg For Years – It’s Not A Simple Story Of Climate Change

The Conversation - Adrian Luckman

NASA / John Sonntag

One of the largest icebergs ever recorded has just broken away from the Larsen C Ice Shelf in Antarctica. Over the past few years I’ve led a team that has been studying this ice shelf and monitoring change. We spent many weeks camped on the ice investigating melt ponds and their impact – and struggling to avoid sunburn thanks to the thin ozone layer. Our main approach, however, is to use satellites to keep an eye on things.

The iceberg would barely fit inside Wales. Adrian Luckman / MIDAS, Author provided

The ice shelves of the Antarctic peninsula. Note Larsen A and B have largely disappeared. AJ Cook & DG Vaughan, 2014, CC BY-SA

We’ve been surprised by the level of interest in what may simply be a rare but natural occurrence. Because, despite the media and public fascination, the Larsen C rift and iceberg “calving” is not a warning of imminent sea level rise, and any link to climate change is far from straightforward. This event is, however, a spectacular episode in the recent history of Antarctica’s ice shelves, involving forces beyond the human scale, in a place where few of us have been, and one which will fundamentally change the geography of this region.
Ice shelves are found where glaciers meet the ocean and the climate is cold enough to sustain the ice as it goes afloat. Located mostly around Antarctica, these floating platforms of ice a few hundred meters thick form natural barriers which slow the flow of glaciers into the ocean and thereby regulate sea level rise. In a warming world, ice shelves are of particular scientific interest because they are susceptible both to atmospheric warming from above and ocean warming from below.
Back in the 1890s, a Norwegian explorer named Carl Anton Larsen sailed south down the Antarctic Peninsula, a 1,000km long branch of the continent that points towards South America. Along the east coast he discovered the huge ice shelf which took his name.
For the following century, the shelf, or what we now know to be a set of distinct shelves – Larsen A, B, C and D – remained fairly stable. However the sudden disintegrations of Larsen A and B in 1995 and 2002 respectively, and the ongoing speed-up of glaciers which fed them, focused scientific interest on their much larger neighbour, Larsen C, the fourth biggest ice shelf in Antarctica.

The author prepares to assist his colleague, Bryn Hubbard from Aberystwyth University, in drilling a borehole in Larsen C using pressurised hot water. MIDAS, Author provided

This is why colleagues and I set out in 2014 to study the role of surface melt on the stability of this ice shelf. Not long into the project, the discovery by our colleague, Daniela Jansen, of a rift growing rapidly through Larsen C, immediately gave us something equally significant to investigate.

Nature at work
The development of rifts and the calving of icebergs is part of the natural cycle of an ice shelf. What makes this iceberg unusual is its size – at around 5,800 km² it’s the size of a small US state. There is also the concern that what remains of Larsen C will be susceptible to the same fate as Larsen B, and collapse almost entirely.

Larsen B once extended hundreds of kilometres over the ocean. Today, one of its glaciers runs straight into the sea. Armin Rose / shutterstock

Our work has highlighted significant similarities between the previous behaviour of Larsen B and current developments at Larsen C, and we have shown that stability may be compromised. Others, however, are confident that Larsen C will remain stable.
What is not disputed by scientists is that it will take many years to know what will happen to the remainder of Larsen C as it begins to adapt to its new shape, and as the iceberg gradually drifts away and breaks up. There will certainly be no imminent collapse, and unquestionably no direct effect on sea level because the iceberg is already afloat and displacing its own weight in seawater.

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This means that, despite much speculation, we would have to look years into the future for ice from Larsen C to contribute significantly to sea level rise. In 1995 Larsen B underwent a similar calving event. However, it took a further seven years of gradual erosion of the ice-front before the ice shelf became unstable enough to collapse, and glaciers held back by it were able to speed up, and even then the collapse process may have depended on the presence of surface melt ponds.

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Even if the remaining part of Larsen C were to eventually collapse, many years into the future, the potential sea level rise is quite modest. Taking into account only the catchments of glaciers flowing into Larsen C, the total, even after decades, will probably be less than a centimetre.

Is this a climate change signal?
This event has also been widely but over-simplistically linked to climate change. This is not surprising because notable changes in the earth’s glaciers and ice sheets are normally associated with rising environmental temperatures. The collapses of Larsen A and B have previously been linked to regional warming, and the iceberg calving will leave Larsen C at its most retreated position in records going back over a hundred years.
However, in satellite images from the 1980s, the rift was already clearly a long-established feature, and there is no direct evidence to link its recent growth to either atmospheric warming, which is not felt deep enough within the ice shelf, or ocean warming, which is an unlikely source of change given that most of Larsen C has recently been thickening. It is probably too early to blame this event directly on human-generated climate change.

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Iceberg Twice Size Of Luxembourg Breaks Off Antarctic Ice Shelf

The Guardian - Nicola Davis

Satellite data confirms 'calving' of trillion-tonne, 5,800 sq km iceberg from the Larsen C ice shelf, dramatically altering the landscape

Vast iceberg splits from Antarctic ice shelf

A giant iceberg twice the size of Luxembourg has broken off an ice shelf on the Antarctic peninsula and is now adrift in the Weddell Sea.
Reported to be "hanging by a thread" last month, the trillion-tonne iceberg was found to have split off from the Larsen C segment of the Larsen ice shelf on Wednesday morning after scientists examined the latest satellite data from the area.
The Larsen C ice shelf is more than 12% smaller in area than before the iceberg broke off – or "calved" – an event that researchers say has changed the landscape of the Antarctic peninsula and left the Larsen C ice shelf at its lowest extent ever recorded.

The Larsen C ice shelf has released an enormous iceberg

Guardian graphic | Image: Earth Observatory, 17 June 2017, data: Adrian Luckman (Swansea University), modified Copernicus Sentinel data

"It is a really major event in terms of the size of the ice tablet that we've got now drifting away," said Anna Hogg, an expert in satellite observations of glaciers from the University of Leeds.
At 5,800 sq km the new iceberg, expected to be dubbed A68, is half as big as the record-holding iceberg B-15 which split off from the Ross ice shelf in the year 2000, but it is nonetheless believed to be among the 10 largest icebergs ever recorded.
The huge crack that spawned the new iceberg grew over a period of years, but between 25 May and 31 May alone, the rift grew by 17km – the largest increase since January. Between the 24 June and 27 June the movement of the ice sped up, reaching a rate of more than 10 metres per day for the already-severed section.
But in the end it wasn't a simple break – data collected just days before the iceberg calved revealed that the rift had branched multiple times. "We see one large [iceberg] for now. It is likely that this will break into smaller pieces as time goes by," said Adrian Luckman, professor of glaciology at Swansea University and leader of the UK's Midas project which is focused on the state of the ice shelf.
Unlike thin layers of sea ice, ice shelves are floating masses of ice, hundreds of metres thick, which are attached to huge, grounded ice sheets. These ice shelves act like buttresses, holding back and slowing down the movement into the sea of the glaciers that feed them.
"There is enough ice in Antarctica that if it all melted, or even just flowed into the ocean, sea levels [would] rise by 60 metres," said Martin Siegert, professor of geosciences at Imperial College London and co-director of the Grantham Institute for Climate Change & Environment. But while the birth of the huge iceberg might look dramatic, experts say it will not itself result in sea level rises. "It's like your ice cube in your gin and tonic – it is already floating and if it melts it doesn't change the volume of water in the glass by very much at all," said Hogg.
Following the collapse of the more northerly Larsen A ice shelf in 1995 and Larsen B in 2002, all eyes have turned to Larsen C.
But Siegert is quick to point out that the calving of the new iceberg is not a sign that the ice shelf is about to disintegrate, stressing that ice shelves naturally break up as they extend further out into the ocean. "I am not unduly concerned about it – it is not the first mega iceberg ever to have formed," he said.
Andrew Shepherd, professor of Earth Observation at the University of Leeds, agreed. "Everyone loves a good iceberg, and this one is a corker," he said. "But despite keeping us waiting for so long, I'm pretty sure that Antarctica won't be shedding a tear when it's gone because the continent loses plenty of its ice this way each year, and so it's really just business as usual!"
Luckman said that while the Larsen C ice shelf might continue to shed icebergs, it might regrow. Nevertheless previous research by the team has suggested that the remaining ice shelf is likely less stable now that the iceberg has calved, although it is unlikely the event would have any short-term effects. "We will have to wait years or decades to know what will happen to the remainder of Larsen C," he said, pointing out that it took seven years after the release of a large iceberg from Larsen B before the ice shelf became unstable and disintegrated.
What's more, Luckman stressed that while large melt ponds were seen on Larsen B prior to its collapse - features which are thought to have affected the structure of the ice shelf - those seen on Larsen C are far smaller and are not even present at this time of year.
And while climate change is accepted to have played a role in the wholesale disintegration of the Larsen A and Larsen B ice shelves, Luckman emphasised that there is no evidence that the calving of the giant iceberg is linked to such processes.
Twila Moon, a glacier expert at the US National Ice and Snow Data Center agrees but, she said, climate change could have made the situation more likely.
"Certainly the changes that we see on ice shelves, such as thinning because of warmer ocean waters, are the sort [of changes] that are going to make it easier for these events to happen," she said.
Luckman is not convinced. "It is a possibility, but recent data from the Scripps Institute of Oceanography actually show most of the shelf thickening," he said.
The progress of the rift, and the loss of the iceberg, has been carefully followed by analysis of radar images from the European Space Agency's Sentinel-1 mission, which provides data from the region every six days.
"Before we would have been lucky if we had got one satellite image a year of an event like this, so we would not have been able to watch it unfold," said Hogg, pointing out that the radar system allows data to be collected whatever the weather and in the dark, while technological advances mean more data that can be downloaded than for previous satellites.

IMAGE

The news of the giant iceberg comes after US president Donald Trump announced that the US will be withdrawing from the 2015 Paris climate accord – an agreement signed by more than 190 countries to tackle global warming. "Truly I am dismayed," said Moon of the move.
Now at the mercy of the ocean currents, the newly calved iceberg could last for decades, depending on whether it enters warmer waters or bumps into other icebergs or ice shelves.

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