If warming exceeds 2°C, Antarctica’s melting ice sheets could raise seas 20 metres in coming centuries



During the Pliocene, up to one third of Antarctica’s ice sheet melted, causing sea-level rise of 20 metres.
from http://www.shutterstock.com, CC BY-ND

Georgia Rose Grant, GNS Science and Timothy Naish, Victoria University of Wellington

We know that our planet has experienced warmer periods in the past, during the Pliocene geological epoch around three million years ago.

Our research, published today, shows that up to one third of Antarctica’s ice sheet melted during this period, causing sea levels to rise by as much as 20 metres above present levels in coming centuries.

We were able to measure past changes in sea level by drilling cores at a site in New Zealand, known as the Whanganui Basin, which contains shallow marine sediments of arguably the highest resolution in the world.

Using a new method we developed to predict the water level from the size of sand particle moved by waves, we constructed a record of global sea-level change with significantly more precision than previously possible.

The Pliocene was the last time atmospheric carbon dioxide concentrations were above 400 parts per million and Earth’s temperature was 2°C warmer than pre-industrial times. We show that warming of more than 2°C could set off widespread melting in Antarctica once again and our planet could be hurtling back to the future, towards a climate that existed three million years ago.




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Overshooting the Paris climate target

Last week we saw unprecedented global protests under the banner of Greta Thunberg’s #FridaysForFuture climate strikes, as the urgency of keeping global warming below the Paris Agreement target of 2°C hit home. Thunberg captured collective frustration when she chastised the United Nations for not acting earlier on the scientific evidence. Her plea resonated as she reminded us that:

With today’s emissions levels, that remaining CO₂ budget [1.5°C] will be entirely gone in less than eight and a half years.

At the current rate of global emissions we may be back in the Pliocene by 2030 and we will have exceeded the 2°C Paris target. One of the most critical questions facing humanity is how much and how fast global sea levels will rise.

According to the recent special report on the world’s oceans and cryosphere by the Intergovernmental Panel on Climate Change (IPCC), glaciers and polar ice sheets continue to lose mass at an accelerating rate, but the contribution of polar ice sheets, in particular the Antarctic ice sheet, to future sea level rise remains difficult to constrain.

If we continue to follow our current emissions trajectory, the median (66% probability) global sea level reached by the end of the century will be 1.2 metres higher than now, with two metres a plausible upper limit (5% probability). But of course climate change doesn’t magically stop after the year 2100.




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Drilling back to the future

To better predict what we are committing the world’s future coastlines to we need to understand polar ice sheet sensitivity. If we want to know how much the oceans will rise at 400ppm CO₂, the Pliocene epoch is a good comparison.

Back in 2015, we drilled cores of sediment deposited during the Pliocene, preserved beneath the rugged hill country at the Whanganui Basin. One of us (Timothy Naish) has worked in this area for almost 30 years and identified more than 50 fluctuations in global sea level during the last 3.5 million years of Earth’s history. Global sea levels had gone up and down in response to natural climate cycles, known as Milankovitch cycles, which are caused by long-term changes in Earths solar orbit every 20,000, 40,000 and 100,000 years. These changes in turn cause polar ice sheets to grow or melt.

While sea levels were thought to have fluctuated by several tens of metres, up until now efforts to reconstruct the precise amplitude had been thwarted by difficulties due to Earth deformation processes and the incomplete nature of many of the cycles.

Our research used a well-established theoretical relationship between the size of the particles transported by waves on the continental shelf and the depth to the seabed. We then applied this method to 800 metres of drill core and outcrop, representing continuous sediment sequences that span a time period from 2.5 to 3.3 million years ago.

We show that during the Pliocene, global sea levels regularly fluctuated between five to 25 metres. We accounted for local tectonic land movements and regional sea-level changes caused by gravitational and crustal changes to determine the sea-level estimates, known as the PlioSeaNZ sea-level record. This provides an approximation of changes in global mean sea level.

Antarctica’s contribution to sea-level rise

Our study also shows that most of the sea-level rise during the Pliocene came from Antarctica’s ice sheets. During the warm Pliocene, the geography of Earth’s continents and oceans and the size of polar ice sheets were similar to today, with only a small ice sheet on Greenland during the warmest period. The melting of the Greenland ice sheet would have contributed at most five metres to the maximum 25 metres of global sea-level rise recorded at Whanganui Basin.

Of critical concern is that over 90% of the heat from global warming to date has gone into the ocean. Much of it has gone into the Southern Ocean, which bathes the margins of Antarctica’s ice sheet.




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Already, we are observing warm circumpolar deep water upwelling and entering ice shelf cavities in several sites around Antarctica today. Along the Amundsen Sea coast of West Antarctica, where the ocean has been heating the most, the ice sheet is thinning and retreating the fastest. One third of Antarctica’s ice sheet — the equivalent to up to 20 metres of sea-level rise — is grounded below sea level and vulnerable to widespread collapse from ocean heating.

Our study has important implications for the stability and sensitivity of the Antarctic ice sheet and its potential to contribute to future sea levels. It supports the concept that a tipping point in the Antarctic ice sheet may be crossed if global temperatures are allowed to rise by more than 2℃. This could result in large parts of the ice sheet being committed to melt-down over the coming centuries, reshaping shorelines around the world.The Conversation

Georgia Rose Grant, Postdoctoral Research Assistant, Paleontology Team, GNS Science and Timothy Naish, Professor, Victoria University of Wellington

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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A landmark report confirms Australia is girt by hotter, higher seas. But there’s still time to act



Aerial imagery revealing the extent of storm damage in Dee Why on Sydney’s Northern Beaches in 2016 following wild weather.
NEARMAP/AAP

Jess Melbourne-Thomas, CSIRO; Kathleen McInnes, CSIRO; Nathan Bindoff, University of Tasmania, and Nerilie Abram, Australian National University

A landmark scientific report has confirmed that climate change is altering the world’s seas and ice at an unprecedented rate. Australia depends on the ocean that surrounds us for our health and prosperity. So what does this mean for us, and life on Earth?

The Intergovernmental Panel on Climate Change (IPCC) findings were launched in Monaco on Wednesday night. They provide the most definitive scientific evidence yet of warmer, more acidic and less productive seas. Glaciers and ice sheets are melting, causing sea level to rise at an accelerating rate.

The implications for Australia are serious. Extreme sea level events that used to hit once a century will occur once a year in many of the world’s coastal places by 2050. This situation is inevitable, even if greenhouse gas emissions are dramatically curbed.

The findings, titled the Special Report on the Ocean and Cryosphere in a Changing Climate, strengthen the already compelling case for countries to meet their emission reduction goals under the 2015 Paris agreement.

Beachgoers cool off in the water at Bondi Beach in Sydney, February 2019. Australia’s coast dwellers must adapt to the inevitable effects of climate change.
Joel Carrett/AAP



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A rapid and dramatic cut in greenhouse gas emissions would prevent the most catastrophic damage to the ocean and cryosphere (frozen polar and mountain regions). This would help protect the ecosystems and people that rely on them.

The report entailed two years of work by 104 authors and review editors from 36 countries, who assessed nearly 7,000 scientific papers and responded to more than 30,000 review comments.

The picture is worse than we thought

Mountain glaciers and polar ice sheets are shrinking and, together with expansion of the warming ocean, are contributing to an increasing rate of sea level rise.

During the last century, global sea levels rose about 15cm. Seas are now rising more than twice as fast – 3.6mm per year – and accelerating, the report shows.

The IPCC’s projections are more dire than in its 2014 oceans report. It has revised upwards by 10% the effect of the melting Antarctic ice sheet on sea level rise by 2100. Antarctica appears to be changing more rapidly than was thought possible even five years ago, and further work is needed to understand just how quickly ice will be lost from Antarctica in future.

Key components and changes of the ocean and cryosphere, and their linkages in the Earth system.
IPCC, 2019

If you live near the Australian coast, change is coming

By 2050, more than one billion of the world’s people will live on coastal land less than 10 metres above sea level. They will be exposed to combinations of sea level rise, extreme winds, waves, storm surges and flooding from intensified storms and tropical cyclones.

Many of Australia’s coastal cities and communities can expect to experience what was previously a once-in-a-century extreme coastal flooding event at least once every year by the middle of this century.

Our island neighbours in Indonesia and the Pacific will also be hit hard. The report warns that some island nations are likely to become uninhabitable – although the extent of this is hard to assess accurately.

Some change is inevitable and we will have to adapt. But the report also delivered a strong message about the choices that still remain. In the case of extreme sea level events around Australia, we believe a marked global reduction in greenhouse as emissions would buy us more than 10 years of extra time, in some places, to protect our coastal communities and infrastructure from the rising ocean.

Indonesian residents wade through flood water in Jakarta. The northwestern part of Jakarta is rapidly sinking.
MAST IRHAM/EPA

More frequent extreme events are often occurring at the same time or in quick succession. Tasmania’s summer of 2015-16 is a good example. The state experienced record-breaking drought which worsened the fire threat in the highlands. An unprecedented marine heatwave along the east coast damaged kelp forests and caused disease and death of shellfish, and the state’s northeast suffered severe flooding.

This string of events stretched emergency services, energy supplies and the aquaculture and manufacturing industries. The total economic cost to the state government was an estimated A$445 million. The impacts on the food, energy and manufacturing sectors cut Tasmania’s anticipated economic growth by about half.

Reefs and fish stocks are suffering

The ocean has taken a huge hit from climate change – taking up heat, absorbing carbon dioxide that makes the water more acidic, and losing oxygen. It will bring ocean conditions unlike anything we have seen before.

Marine ecosystems and fisheries around the world are under pressure from this barrage of stressors. Overall, the fisheries potential around Australia’s coasts is expected to decline during this century.

Heat build-up in the surface ocean has already triggered a marked rise in the intensity, frequency and duration of marine heatwaves. Ocean heatwaves are expected to become between four and ten times more common this century, depending on how rapidly global warming continues.

The report said coral reefs, including the Great Barrier Reef, are already at very high risk from climate change and are expected to suffer significant losses and local extinctions. This would occur even if global warming is limited to 1.5℃ – a threshold the world is set to overshoot by a wide margin.




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Our choices now are critical for the future

This report reinforces the findings of earlier reports on the importance of limiting global warming warming to 1.5℃ if we are to avoid major impacts on the land, the ocean and frozen areas.

Even if we act now to drastically reduce greenhouse gas emissions, some damage is already locked in and our ocean and frozen regions will continue to change for decades to centuries to come.

Mertz Glacier in east Antarctica. IPCC scientists say the expected effect of melting Antarctic ice on sea level rise is worse than projected five years ago.
Australian Antarctic Division

In Australia, we will need to adapt our coastal cities and communities to unavoidable sea level rise. There are a range of possible options, from building barriers to planned relocation, to protecting the coral reefs and mangroves that provide natural coastal defences.

But if we want to give adaptation the best chance of working, the clear message of this new report is that we need to reduce greenhouse gas emissions as quickly as possible.The Conversation

Jess Melbourne-Thomas, Transdisciplinary Researcher & Knowledge Broker, CSIRO; Kathleen McInnes, Senior research scientist, CSIRO; Nathan Bindoff, Professor of Physical Oceanography, Institute for Marine and Antarctic Studies, University of Tasmania, and Nerilie Abram, ARC Future Fellow, Research School of Earth Sciences; Chief Investigator for the ARC Centre of Excellence for Climate Extremes, Australian National University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Climate change may change the way ocean waves impact 50% of the world’s coastlines


Mark Hemer, CSIRO; Ian Young, University of Melbourne; Joao Morim Nascimento, Griffith University, and Nobuhito Mori, Kyoto University

The rise in sea levels is not the only way climate change will affect the coasts. Our research, published today in Nature Climate Change, found a warming planet will also alter ocean waves along more than 50% of the world’s coastlines.

If the climate warms by more than 2℃ beyond pre-industrial levels, southern Australia is likely to see longer, more southerly waves that could alter the stability of the coastline.

Scientists look at the way waves have shaped our coasts – forming beaches, spits, lagoons and sea caves – to work out how the coast looked in the past. This is our guide to understanding past sea levels.




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But often this research assumes that while sea levels might change, wave conditions have stayed the same. This same assumption is used when considering how climate change will influence future coastlines – future sea-level rise is considered, but the effect of future change on waves, which shape the coastline, is overlooked.

Changing waves

Waves are generated by surface winds. Our changing climate will drive changes in wind patterns around the globe (and in turn alter rain patterns, for example by changing El Niño and La Niña patterns). Similarly, these changes in winds will alter global ocean wave conditions.




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Further to these “weather-driven” changes in waves, sea level rise can change how waves travel from deep to shallow water, as can other changes in coastal depths, such as affected reef systems.

Recent research analysed 33 years of wind and wave records from satellite measurements, and found average wind speeds have risen by 1.5 metres per second, and wave heights are up by 30cm – an 8% and 5% increase, respectively, over this relatively short historical record.

These changes were most pronounced in the Southern Ocean, which is important as waves generated in the Southern Ocean travel into all ocean basins as long swells, as far north as the latitude of San Francisco.

Sea level rise is only half the story

Given these historical changes in ocean wave conditions, we were interested in how projected future changes in atmospheric circulation, in a warmer climate, would alter wave conditions around the world.

As part of the Coordinated Ocean Wave Climate Project, ten research organisations combined to look at a range of different global wave models in a variety of future climate scenarios, to determine how waves might change in the future.

While we identified some differences between different studies, we found if the 2℃ Paris agreement target is kept, changes in wave patterns are likely to stay inside natural climate variability.

However in a business-as-usual climate, where warming continues in line with current trends, the models agreed we’re likely to see significant changes in wave conditions along 50% of the world’s coasts. These changes varied by region.

Less than 5% of the global coastline is at risk of seeing increasing wave heights. These include the southern coasts of Australia, and segments of the Pacific coast of South and Central America.

On the other hand decreases in wave heights, forecast for about 15% of the world’s coasts, can also alter coastal systems.

But describing waves by height only is the equivalent of describing an orchestra simply by the volume at which it plays.

Some areas will see the height of waves remain the same, but their length or frequency change. This can result in more force exerted on the coast (or coastal infrastructure), perhaps seeing waves run further up a beach and increasing wave-driven flooding.

Similarly, waves travelling from a slightly altered direction (suggested to occur over 20% of global coasts) can change how much sand they shunt along the coast – important considerations for how the coast might respond. Infrastructure built on the coast, or offshore, is sensitive to these many characteristics of waves.

While each of these wave characteristics is important on its own, our research identified that about 40% of the world’s coastlines are likely to see changes in wave height, period and direction happening simultaneously.

While some readers may see intense waves offering some benefit to their next surf holiday, there are much greater implications for our coastal and offshore environments. Flooding from rising sea levels could cost US$14 trillion worldwide annually by 2100 if we miss the target of 2℃ warming.




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How coastlines respond to future climate change will be a response to a complex interplay of many processes, many of which respond to variable and changing climate. To focus on sea level rise alone, and overlooking the role waves play in shaping our coasts, is a simplification which has great potential to be costly.


The authors would like to acknowledge the contribution of Xiaolan Wang, Senior Research Scientist at Environment and Climate Change, Canada, to this article.The Conversation

Mark Hemer, Principal Research Scientist, Oceans and Atmosphere, CSIRO; Ian Young, Kernot Professor of Engineering, University of Melbourne; Joao Morim Nascimento, PhD Candidate, Griffith University, and Nobuhito Mori, Professor, Kyoto University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Arctic ice loss is worrying, but the giant stirring in the South could be even worse



Field camp on the East Antarctic ice sheet.
Nerilie Abram

Nerilie Abram, Australian National University; Matthew England, UNSW, and Matt King, University of Tasmania

A record start to summer ice melt in Greenland this year has drawn attention to the northern ice sheet. We will have to wait to see if 2019 continues to break ice-melt records, but in the rapidly warming Arctic the long-term trends of ice loss are clear.

But what about at the other icy end of the planet?

Antarctica is an icy giant compared to its northern counterpart. The water frozen in the Greenland ice sheet is equivalent to around 7 metres of potential sea level rise. In the Antarctic ice sheet there are around 58 metres of sea-level rise currently locked away.

Like Greenland, the Antarctic ice sheet is losing ice and contributing to unabated global sea level rise. But there are worrying signs Antarctica is changing faster than expected and in places previously thought to be protected from rapid change.

The threat from beneath

On the Antarctic Peninsula – the most northerly part of the Antarctic continent – air temperatures over the past century have risen faster than any other place in the Southern Hemisphere. Summer melting already happens on the Antarctic Peninsula between 25 and 80 days each year. The number of melt days will rise by at least 50% when global warming hits the soon-to-be-reached 1.5℃ limit set out in the Paris Agreement, with some predictions pointing to as much as a 150% increase in melt days.

But the main threat to the Antarctic ice sheet doesn’t come from above. What threatens to truly transform this vast icy continent lies beneath, where warming ocean waters (and the vast heat carrying capacity of seawater) have the potential to melt ice at an unprecedented rate.




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Almost all (around 93%) of the extra heat human activities have caused to accumulate on Earth since the Industrial Revolution lies within the ocean. And a large majority of this has been taken into the depths of the Southern Ocean. It is thought that this effect could delay the start of significant warming over much of Antarctica for a century or more.

However, the Antarctic ice sheet has a weak underbelly. In some places the ice sheet sits on ground that is below sea level. This puts the ice sheet in direct contact with warm ocean waters that are very effective at melting ice and destabilising the ice sheet.

Scientists have long been worried about the potential weakness of ice in West Antarctica because of its deep interface with the ocean. This concern was flagged in the first report of the Intergovernmental Panel on Climate Change (IPCC) way back in 1990, although it was also thought that substantial ice loss from Antarctica wouldn’t be seen this century. Since 1992 satellites have been monitoring the status of the Antarctic ice sheet and we now know that not only is ice loss already underway, it is also vanishing at an accelerating rate.

The latest estimates indicate that 25% of the West Antarctic ice sheet is now unstable, and that Antarctic ice loss has increased five-fold over the past 25 years. These are remarkable numbers, bearing in mind that more than 4 metres of global sea-level rise are locked up in the West Antarctic alone.

Antarctic ice loss 1992–2019, European Space Agency.




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Thwaites Glacier in West Antarctica is currently the focus of a major US-UK research program as there is still a lot we don’t understand about how quickly ice will be lost here in the future. For example, gradual lifting of the bedrock as it responds to the lighter weight of ice (known as rebounding) could reduce contact between the ice sheet and warm ocean water and help to stabilise runaway ice loss.

On the other hand, melt water from the ice sheets is changing the structure and circulation of the Southern Ocean in a way that could bring even warmer water into contact with the base of the ice sheet, further amplifying ice loss.

There are other parts of the Antarctic ice sheet that haven’t had this same intensive research, but which appear to now be stirring. The Totten Glacier, close to Australia’s Casey station, is one area unexpectedly losing ice. There is a very pressing need to understand the vulnerabilities here and in other remote parts of the East Antarctic coast.

The other type of ice

Sea ice forms and floats on the surface of the polar oceans. The decline of Arctic sea ice over the past 40 years is one of the most visible climate change impacts on Earth. But recent years have shown us that the behaviour of Antarctic sea ice is stranger and potentially more volatile.

The extent of sea ice around Antarctica has been gradually increasing for decades. This is contrary to expectations from climate simulations, and has been attributed to changes in the ocean structure and changing winds circling the Antarctic continent.

But in 2015, the amount of sea ice around Antarctica began to drop precipitously. In just 3 years Antarctica lost the same amount of sea ice the Arctic lost in 30.




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So far in 2019, sea ice around Antarctica is tracking near or below the lowest levels on record from 40 years of satellite monitoring. In the long-term this trend is expected to continue, but such a dramatic drop over only a few years was not anticipated.

There is still a lot to learn about how quickly Antarctica will respond to climate change. But there are very clear signs that the icy giant is awakening and – via global sea level rise – coming to pay us all a visit.The Conversation

Nerilie Abram, ARC Future Fellow, Research School of Earth Sciences; Chief Investigator for the ARC Centre of Excellence for Climate Extremes, Australian National University; Matthew England, Australian Research Council Laureate Fellow; Deputy Director of the Climate Change Research Centre (CCRC); Chief Investigator in the ARC Centre of Excellence in Climate System Science, UNSW, and Matt King, Professor, Surveying & Spatial Sciences, School of Technology, Environments and Design, University of Tasmania

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Rising seas threaten Australia’s major airports – and it may be happening faster than we think



Sydney’s airport is one of the most vulnerable in Australia to sea level rise.
Shutterstock

Thomas Mortlock, Macquarie University; Andrew Gissing, Macquarie University; Ian Goodwin, Macquarie University, and Mingzhu Wang

Most major airports in Australia are located on reclaimed swamps, sitting only a few metres above the present day sea level. And the risk of sea level rise from climate change poses a greater threat to our airports than we’re prepared for.

In fact, some of the top climate scientists now believe global sea-level rise of over two metres by 2100 is likely under our current trajectory of high carbon emissions.




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This makes Cairns (less than 3m above sea level), Sydney and Brisbane (under 4m), and Townsville and Hobart (both around under 5m) airports among the most vulnerable.

Antarctica’s ice sheets could be melting faster than we think.
Tanya Patrick/CSIRO science image, CC BY

In the US, the National Oceanic and Atmospheric Administration (NOAA) has recommended that global mean sea level rise of up to 2.7 metres this century should be considered in planning for coastal infrastructure.

This is two to three times greater than the upper limit of recommended sea level rise projections applied in Australia.

But generally, the amount of sea level rise we can expect over the coming century is deeply uncertain. This is because ice sheet retreat rates from global warming are unpredictable.




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Given the significant disruption cost and deep uncertainty associated with the timing of sea level rise, we must adopt a risk-based approach which considers extreme sea level rise scenarios as part of coastal infrastructure planning.

Are we prepared?

As polar ocean waters warm, they can cause glaciers to melt from beneath, leading to more icebergs breaking off into the ocean and then a rapid rise in global sea level. This has happened multiple times in the Earth’s past and, on some occasions, in a matter of decades.

The Intergovernmental Panel on Climate Change (IPCC) puts sea level rise projections for Australia somewhere between 50 to 90 centimetres by 2090, relative to the average sea level measured between 1986 to 2005. But the emerging science indicates this may now be an underestimate.

Some studies suggest if substantive glacial basins of the West Antarctic Ice Sheet were to collapse, it could contribute at least a further two metres to global sea levels.

Most Australian airports have conducted risk assessments for the IPCC projections.

In fact, there is no state-level policy that considers extreme sea level rise for the most critical infrastructure, even though it is possible sea levels could exceed those recommended by the IPCC within the coming century.




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And for airports, the planning implications are stark when you compare the current projection of less than a metre of sea level rise and the potential of at least a two metre rise later this century.

Taking the most low-lying major airports in Australia as an example, our modelling suggests a collapse of the West Antarctic Ice Sheet would see their near complete inundation – without any adaptation in place.

For more elevated locations, coastal infrastructure may still be inoperable more frequently when the combined effect of storm surges, waves, elevated groundwater or river flooding are considered.

A $200 billion problem

Our airports and other forms of infrastructure near the coastline are critical to the Australian economy. The aviation industry has an estimated annual revenue of over A$43 billion, adding around A$16 billion to the economy in 2017.

While there are many uncertainties around the future cost of sea-level rise, a study by the Climate Council suggests over a metre sea level rise would put more than A$200 billion worth of Australian infrastructure at risk.

It is difficult to assign a probability and time-frame to ice sheet collapse, but scientific estimates are reducing that time frame to a century rather than a millennium.




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Uncertainty generally comes with a cost, so proactive planning would make economic sense.

Adapting our most critical coastal assets while sea levels rapidly rise is not an option – mitigation infrastructure could take decades to construct and may be prohibitively expensive.

Given the deep uncertainties associated with the timing of ice-sheet collapse, we suggest airport and other critical coastal infrastructure is subjected to risk analysis for a two to three metre sea level rise.The Conversation

Thomas Mortlock, Senior Risk Scientist, Risk Frontiers, Adjunct Fellow, Macquarie University; Andrew Gissing, General Manager, Risk Frontiers, Adjunct Fellow, Macquarie University; Ian Goodwin, Associate Professor, Macquarie University, and Mingzhu Wang, Senior Geospatial Scientist, Risk Frontiers, Adjunct Fellow, Macquarie University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Climate change forced these Fijian communities to move – and with 80 more at risk, here’s what they learned


File 20190430 136787 bz9zdf.jpg?ixlib=rb 1.1
Many houses were flattened after Tropical Cyclone Evan, leading to the partial relocation of the Fijian viillage Denimanu.
Rowena Harbridge/AusAID, CC BY-SA

Annah Piggott-McKellar, The University of Queensland; Karen Elizabeth McNamara, The University of Queensland, and Patrick D. Nunn, University of the Sunshine Coast

The original Fijian village of Vunidogoloa is abandoned. Houses, now dilapidated, remain overgrown with vegetation. Remnants of an old seawall built to protect the village is a stark reminder of what climate change can do to a community’s home.

Vunidogoloa is one of four Fijian communities that have been forced to relocate from the effects of climate change. And more than 80 communities have been earmarked by the Fiji government for potential future relocation.




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Low lying coastal communities like these are especially vulnerable to threats of sea-level rise, inundation of tides, increased intensity of storm surges and coastal erosion. Extreme, sudden weather events such as cyclones can also force communities to move, particularly in the tropics.

But relocating communities involves much more than simply rebuilding houses in a safer location.

It involves providing the right conditions for people to rebuild the lives they knew, such as equitable access to resources and services, social capital and community infrastructure.

Our research documents the experiences and outcomes of relocation for two of these Fijian communities – Vunidogoloa and Denimanu.

The relocated villages

My colleagues and I visited Vunidogoloa and Denimanu, villages in Fiji’s Northern Islands, at the end of 2017 and spoke to village leaders and community members to learn how they felt about the relocation process.

All 153 residents of Vunidogoloa and roughly half of the 170 people in Denimanu moved away from their climate ravaged homes.

Map of Fiji showing the two case study sites.
Author provided

Flooding in Vunidogoloa

Vunidogoloa is a classic example of the slow creep of climate change. For a number of decades the residents have fought coastal flooding, salt-water intrusion and shoreline erosion. The village leaders approached the Fijian government, asking to be relocated to safer ground.

The relocation was originally set for 2012 but, after delays, the entire village moved roughly 1.5 kilometres inland two years later. This is often recognised as the first ever village in Fiji to relocate from climate change.

The new village relocation site of Vunidogoloa.

Cyclone in Denimanu

In contrast to Vunidogoloa, Denimanu experienced sudden onset effects of climate change.

While the village had been experiencing encroaching shorelines for years, it was Tropical Cyclone Evan, which hit in 2012 destroying 19 houses closest to the shoreline, that prompted relocation.




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These homes were rebuilt roughly 500 metres from the original site on a hill slope. With the remaining houses still standing on the original site, the village was only partially moved.

The new village relocation site of Denimanu.
Author provided

Was relocation a success?

The relocation was a success in Vunidogoloa, and residents said they now feel much safer from climate change hazards. One villager told us:

We were so fearful because of the tides living at the old site. We were happy to move away from that fear.

But in Denimanu, where the relocated villagers live on a slope, fears of coastal threats have now been replaced by a fear of potential landslides. This is especially concerning as the village’s primary school was recently destroyed by a nearby landslide.

A relocated Denimanu local said:

We were delighted with the move to the new houses, but we were still worried about the landslide because the houses were on the hill and we know this place.

The landslide that destroyed the primary school in Denimanu village.

Ultimately, residents in both villages were happy with many aspects of the relocation process.

For example, they were provided solar power, rainwater tanks, and household facilities that weren’t available in the original villages. Vunidogoloa also received pineapple plants, cattle, and fish ponds, which have helped reestablish their livelihoods.

But it’s not all good news. While new housing was built for the community, they were built to a poor standard, with leaking through the doors and walls, especially in periods of high rainfall. Fiji is located in the tropics, so these infrastructure problems are likely to get worse.




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And moving the Vunidogoloa villagers away from the ocean might damage their livelihoods, as fishing is one of their dominant sources of food. The ocean also provides an important spiritual connection for local people.

The impacts of climate change are set to rise, especially if global action to halt greenhouse gas emissions stagnates. More vulnerable communities will need to move away from their current homes.

While relocating communities to safer, less exposed areas is one option to help people manage climate hazards, it’s not a viable solution for all those affected.

Our research shows relocation must be done in a manner that accounts for the rebuilding of local livelihoods, with sustainable adaptation solutions that put local priorities at the centre of this process.

And we need them before more coastal villages are impacted by both slow and sudden onset climate impacts, putting more people in danger.The Conversation

Annah Piggott-McKellar, PhD Candidate, The University of Queensland; Karen Elizabeth McNamara, Senior lecturer, The University of Queensland, and Patrick D. Nunn, Professor of Geography, School of Social Sciences, University of the Sunshine Coast

This article is republished from The Conversation under a Creative Commons license. Read the original article.