29/06/2017

Climate Change Could Threaten Up To 2 Billion Refugees By 2100

Huffington Post - Alexander C. Kaufman

In this August 2016 photo, a family on a raft approaches a boat in a flooded area of Jamalpur, Bangladesh. Probal Rashid via Getty Images
Charles Geisler, a sociologist at Cornell University, spent much of his career researching where poor people go when rich corporations swoop in and buy the land out from under their feet.
But his focus began to shift in 2005, after observing how storm surges tainted farmland in Bangladesh with salt water. Later that year, Hurricane Katrina struck New Orleans, submerging communities once believed to be safe behind levees and dikes. As floodwaters inundated Vietnam’s Mekong Delta last year, Geisler’s new worldview came into sharp relief.
The rising sea, he surmised, is the one displacement force more powerful than greed.
Geisler began collating climate and demographic research, and came to a dire conclusion: By the year 2100, rising sea levels could force up to 2 billion people inland, creating a refugee crisis among one-fifth of the world’s population.
Worse yet, there won’t be many places for those migrants to go.
His findings appear in the July issue of the journal Land Use Policy.
“We have a pending crisis,” Geisler, a professor emeritus of development sociology at Cornell, told HuffPost. “This relocation and huge mass migration from the coastal zone, it’s going to take place in this century and the next century.”
To get the 2 billion figure, Geisler extrapolated from a 2015 study published in the journal PLOS One. That research predicted that by 2060, there would be some 1.4 billion people living in low-lying coastal regions at risk from sea level rise. Drawing from nearly a dozen other studies, Geisler and his co-author, the University of Kentucky climate researcher Ben Currens, modeled what he called a “rather extreme scenario.”
“The paper is the worst-case scenario,” Geisler said. “We looked for estimates in these various barriers to entry that were coming from the most draconian changes that could hit us from climate change and sea level rise.”
Geisler outlined three obstacles, or “barriers to entry,” to relocating people driven inland from their homes by rising seas. The first problem is that climate change isn’t just affecting coastal communities. Droughts and desertification could make areas safe from sea level rise uninhabitable at worst, and incapable of sustaining a large influx of migrants at best, Geisler said. The second issue is closely linked: If climate refugees flock to cities, increasing the urban sprawl into land once used to farm food, those metropoles could lose the ability to feed their inflated populations.
The third issue involves physical and legal barriers, meaning regions and municipalities might erect walls and post guards to prevent climate migrants from entering and settling down. Geisler dubbed this phenomenon the “no-trespass zone.”
Geisler warned that too much of the conversation around climate adaptation is focused on building sea walls, learning to live with regular flooding, and relocating communities inland, as has happened in Alaska. These limited ideas of “adaptation” could leave humanity woefully unprepared for a mass migration that Geisler said could dwarf the current refugee crisis in Europe, driven by war, poverty and drought-linked famine in regions south and east of the continent. At least 65.6 million people have fled their homes, and the United Nations estimates that 20 people are forcibly displaced every minute by war and persecution alone. Adding unfettered climate change to that mix threatens to yield human catastrophe on a scale that is difficult to describe without sounding bombastic.
The U.S. is particularly at risk. Millions of mainland Americans could be forced to flee inland, sending the populations of at least nine coastal states downward, according a University of Georgia study released in April. Texas alone could have to take in as many as 2.5 million internal migrants.
The rising sea, he surmised, is the one displacement force more powerful than greed.
“My hope is that this paper will reorient planners and policymakers who use the term ‘adaptation’ in a very narrow way,” Geisler said. “It’s used either to mean fortifying coastal structures to keep the sea off the land, or it’s used to refer to moving a population from a coastal zone in some organized way.”
There are better ways to prepare, he said. He pointed to four counties in South Florida that began sharing hydrological data and research on the rate of sea level rise, then drafted a joint evacuation plan. Dealing with the possible results of runaway climate change requires “transboundary” planning, he said.
“Climate change is going to be with us for a long time, and the coastal zone population is going to be overwhelming as it moves inland,” Geisler said. “How are we going to employ these people? Where are we going to house them? What energy sources are they going to need?”
“Bottom line: Far more people are going to be living on far less land, and land that is not as fertile and habitable and sustainable as the low-elevation coastal zone,” he added. “And it’s coming at us faster than we thought.”

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Climate Scientists Reveal Their Fears For The Future

ABC Lateline - Kerry Brewster

Climate scientists rarely speak publicly about their personal views. But in the wake of some extreme weather events in Australia, the specialists who make predictions about our climate reveal they're experiencing sometimes deep anxieties.


Transcript
DR SARAH PERKINS-KIRKPATRICK, RESEARCH FELLOW, UNSW CLIMATE CHANGE RESEARCH CENTRE: I think this one, it's one of my favourites.

KERRY BREWSTER: Four climate scientists at different stages in their lives and careers reveal the burden of knowing what predicted climate changes will bring.

PROF. KATRIN MEISSNER, DIRECTOR, UNSW CLIMATE CHANGE RESEARCH CENTRE:
I think for years I was really living in two different worlds. I was a scientist at work who was just objectively looking at numbers, and, um, then over years starting to be more and more worried about my own life, but I separated it completely from my private life.
I think that was a little bit of a self-protection.
'That doesn't really work that well anymore. In the past few years, I carry this knowledge with me wherever I am.
That looks beautiful, Kaitlin! That looks amazing. Look at this.
My name is Katrin Meissner, I'm the director of the Climate Change Research Centre of the University of New South Wales.
I have been working in this field for the last 20 years and I have been mapping lots of concerning trends in that time.
Many people do not really understand how big a threat climate change is to humanity.
The changes that we see right now are much faster than anything we have seen in the climate history and that concerns me because it means that ecosystems might not be able to adapt.
It's going to be dramatic. It's going to be very dramatic.

SARAH PERKINS-KIRKPATRICK: I think one day in the last heatwave I measured 45 degrees outside in the shade in our front patio, and it was 39 on the inside. I was sleeping with wet towels on my legs to keep cool.
I'm Sarah Perkins-Kirkpatrick and I'm a research fellow at the University of New South Wales and when I look at is heatwaves, so how they have changed, why they have changed, what their changes will be in the future, how we measure them and the role of climate change behind the heatwaves.
I had conversations with my husband as these heatwaves were occurring in summer, going, "Are we doing the right thing? Is it right to bring kids into this world?" with me knowing how bad it's going to be.
There is so much wrong with climate change and there are so many impacts that we're already looked into that I can't change, that no-one can really change. It's going to be bad and it's almost why would you inflict that on someone?

JUSTIN OOGERS, PHD STUDENT, UNIVERSITY OF MELBOURNE: Okay, so that's where it's going to go.
My name is Justin Oogers, I'm doing a PhD at the University of Melbourne just looking at urban micro climate as it is now and looking at how we can improve it into the future.
We need to be able to plan our cities better, we need to be able to design them better, keeping in mind what's coming, keeping in mind these temperatures that are getting into the 50s in Melbourne, and often I can't believe that I'm saying that, but the computer models, all the research is telling us, this is what's coming.
Yeah, it's tragic. Whenever I talk to my wife about heatwaves, she gets scared of them and unfortunately I can't really give her any good news.
I have been married for about five years. Yes, we want children, but we're quite concerned about it, even scared of it.
Our parents both want us to have children and there's lot of joy that comes with having children, but at the same time, knowing what's coming with climate change, we have actually just been putting it off.

PROFESSOR DAVE GRIGGS, DIRECTOR, MONASH SUSTAINABLE DEVELOPMENT INSTITUTE: You can say you don't believe in gravity but the apple is still going to hit you on the head. You can say you don't believe in climate change but it's not going to stop it getting it hotter.
I think Australia is the most vulnerable developed country in the world to climate change.
My name is Professor David Griggs, I work at the Monash Sustainable Institute at Monash University.
My background is as a climate scientist and atmospheric physicist. In the past I had been the head of the intergovernmental panel on climate change, science working group secretariat. I have been director of the Hadley Centre for Climate Change which is the UK government research centre into climate change and I've been the vice-chair of the World Climate Research Programme.
I think we're heading into a future with a considerably greater warming than two degrees and when the world doesn't do something about it, that brings a whole range of emotions into play.
I mean, depression is what is clearly something, you know, you get days when you're down because you just, what you know and what you can see coming is not good.
For people living in Australia, it means that a lot of people will suffer and a lot of people will die.
The problem is nobody's death certificate will say this person died of climate change. It will say they will die of heat stress, or cardiac arrest or they died in a bushfire.

SARAH PERKINS-KIRKPATRICK: Climate scientists are under a lot of scrutiny. We get ridiculed a lot by certain people for being alarmists, by going too much into detail. Where in actual fact we're actually probably reservists and are very conservative in our estimates and make sure we're so sure of the numbers before we actually get them out there.
I don't like to scare people, but the future is not looking very good.

DAVE GRIGGS: I'm fortunate in that I live in Melbourne at the moment and Melbourne is one of the more climate adapted cities in Australia.
If I was living in Darwin or Brisbane, I would be seriously thinking about moving.
One of the important things about climate change when you think of it in the context of sustainable development...

KERRY BREWSTER: Among climate scientists the conversation is turning to their personal plans.

DAVE GRIGGS: We'll talk about where we're planning to retire to or where we're planning to move to, how we're planning to, you know, safeguard our families from, in the future.
And the consensus seems to be Tasmania. Tassie because it's the furthest south, it's the coolest.

SARAH PERKINS-KIRKPATRICK: We have thrown up the idea, you know, the potential if the opportunity came up is moving to Canberra. It's a city, it's got good infrastructure, it's got good employment opportunities.
Yes, it gets warm there and yes, it's a dry climate but the temperature doesn't get as hot as Sydney. Their night-time temperatures are a lot cooler and you can cope with extreme heat much better if you got cooler night-time temperatures to sleep.

JUSTIN OOGERS: For me and my wife, anywhere, maybe forced to move further south, and I'm sure that there's a lot of other people that are probably thinking the same thing.
My grandpa decided to move down to the coolest part of Australia. He's living on a boat south of Hobart and he's trying to drag me down to Tasmania. He's saying, "The University of Tasmania is down here. Should come down here", and I have often said to him I'd think about it.
My wife, she is a lot more keen to do it.

KATRIN MEISSNER: I find it really hard to decide on one particular region saying this one is going to be safe and we are just going to lock this one in.
I don't think there will be any safe places. I am, the impacts are going to be big.
So my approach is to be as mobile, as flexible as possible to be able to adapt to whatever is going to happen. My children are bilingual and we're working on a third language.
Both children have three passports, and they actually have the freedom to be able to study and work even in the European Union, or in Canada or in Australia.

KERRY BREWSTER:
After scoping New Zealand and Tasmania, Professor Griggs has settled on his native England as a climate change retreat.

DAVE GRIGGS: London is over here on the right-hand side. So we're down here in the south-west with Devon and Cornwall.
This is the house. Just a traditional old English farm house built around 1800. That's my vegetable patch so that's where I can grow my own food.
I have certainly taken a look at this and looked at the climate projections and said yeah, that's going to be good for the next sort of 100 years or so.
When, some new fact comes in that makes me fearful, I think, well, at least, you know, I have done what I can to protect my family.
I can't protect them from changes in the global economy. I can't protect them from, you know, mass migrations, I can't protect them from, you know, some of the impacts that they are going to be, no matter where I move to and no matter where I buy my house, but I can do what I can.

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Guest Post: Is The Collapse Of The West Antarctic Ice Sheet Inevitable?

Carbon Brief - Prof Christina Hulbe* | Dr Christian Ohneiser*

Aerial view of Antarctica from NASA's IceBridge project, which has allowed scientists to determine that the West Antarctic Ice Sheet may be in irreversible decline. Credit: NASA.
In the late 1970s, glaciologist John Mercer was one of the first scientists to warn of “rapid deglaciation” of the West Antarctic Ice Sheet under human-caused warming. Other scientists, studying both modern Antarctica and the geologic record of its past, soon came to a similar conclusion.
Forty years on, with more observations and a better understanding of ice sheet processes, scientists have a clearer idea of how the ice sheet is changing. Yet different models still give different projections of when retreat of the West Antarctic Ice Sheet passes the point of no return.
So, is the eventual collapse of the West Antarctic Ice Sheet already inevitable? Model projections under low emissions scenarios suggest that ice sheet retreat could stabilise, but under medium and high scenarios, collapse is unstoppable.

Chain reaction
Ice sheets form where snow accumulates, densifies, and remains stored as ice on the land surface. Antarctica’s massive ice sheets sit astride the cold, windswept continental interior and funnel down towards the (relatively) warm ocean around the coast.
Where the ice meets the water, floating ice shelves form. These are seaward extensions of the ice sheet that connect land-based ice with relatively fast-changing parts of the climate system. Changing winds and warmer oceans bring warm water into contact with the floating ice, increasing the rate at which it melts.
Ocean-driven ice loss is already underway where the West Antarctic Ice Sheet flows into the Amundsen Sea. The best observations available indicate that relatively warm Circumpolar Deep Water has been able to intrude onto the Amundsen Sea continental shelf over the last few decades. The continental shelf is the area of seabed immediately surrounding a land mass, where the sea is relatively shallow compared to the open ocean beyond it.
The warmer-than-usual water increases the melt rate on the underside of floating ice shelves, causing them to thin. For the West Antarctic Ice Sheet, this thinning sets up a chain reaction that scientists think could be unstoppable.
The interdisciplinary and multi-institution Aotearoa New Zealand Ross Ice Shelf research programme aims to understand the processes and process interactions that determine how the ice shelf will respond to future warming. This field camp is in the middle of the ice shelf, about 350 km from Scott Base, at location selected to balance our interests in sub-ice oceanography, ice/atmosphere interaction, glaciology, and sedimentary records of the past. Later this year, we will return to the site with a hot water drill built at Victoria University of Wellington to bore through the ice to observe the ice/ocean interface directly, measure ocean properties, and sample sediments on the sea floor. Credit: Christina Hulbe.
‘Self-sustaining retreat’
In West Antarctica, most of the ice sheet rests on the seafloor, and the basin that it sits in grows deeper with distance from the coastline. This makes it particularly susceptible to a “self-sustaining retreat”.
The base of the ice sheet is below sea level, which means that the warm ocean can melt and thin the ice at the “grounding line” – the boundary between the grounded ice sheet and the floating ice shelf.
If we were to take only one measure of the well-being of the West Antarctic Ice Sheet, it would probably be the position of the grounding line. The position of the grounding line indicates the balance between water stored in the ice sheet and water returned to the sea. Processes acting at the grounding line can also drive the grounded ice to change.
Melting alone can cause grounding line retreat and sea level rise. But melting can also initiate something called the “marine ice sheet instability”. “Marine” because the base of the ice sheet is below sea level, and “instability” for the fact that once it starts, the retreat is self-sustaining.
Here’s how it works. If changes on the floating side cause ice on the grounded side to lift off from the seafloor and float, the grounding line will retreat. Because the ice flows more rapidly when it is floating than it did when grounded, the rate of ice flow near the grounding line will increase. Faster flow means thinning, which may in turn cause more ice to lift off and float. Because greater thickness also causes the ice to flow faster, grounding line retreat into the deep can also produce faster flow.
You can see this explained in the figure below.
Diagram showing why the West Antarctic Ice Sheet is particularly susceptible to runaway grounding line retreat. Source: Hulbe (2017).
Not whether ice sheets retreat, but how fast
It is not clear yet if this instability has already started along the Amundsen Sea coast. If it hasn’t, and if the ocean warming stops, the grounding line should balance out at a new location. If it has, the retreat will continue no matter what happens next.
Model predictions of the future of the ice sheet can vary by a factor of 10 or more for the same emissions scenarios. These differences depend on how the processes through which climate forces the ice to change are represented in the models. But the question isn’t whether or not climate change will drive ice sheet retreat, the question is how fast it will go, and the extent to which policy decisions to affect our carbon emissions can make a difference to the outcome.
Under medium and high emissions scenarios, the models agree that the West Antarctic Ice Sheet will eventually collapse. At the higher end, marine-based sections of the East Antarctic ice sheet also retreat. However, under low emissions scenarios – lower than our current pathway – retreat may be limited.
If the marine ice sheet instability has not been initiated, then once the warming stops, the rate of retreat declines and grounding lines stabilise. The implication is that wholesale loss of the West Antarctic Ice Sheet may not be inevitable. But the low-end ice sheet scenarios are not well understood and the more scientists study the geologic record of past ice sheet change, the more vulnerable the ice sheets appear to be.
Earth’s climate has been oscillating between relatively warm (interglacial) and relatively cold (glacial) conditions for the last five million years. Even before human influences on climate, those swings appear to have driven grounding line retreat deep into the West Antarctic Ice Sheet interior. Some of the warm swings were into what are called “super-interglacial” conditions. During these times, southern oceans were between 3C and 8C warmer than at present, the ice sheets were smaller, and global sea levels were higher than today.
The causes and timings of super-interglacials are not well understood and even the models most responsive to changing temperatures can’t reproduce the speed of ice loss. But these records make clear how sensitive the Antarctic ice sheets are to climate change, even before the extra kick from global warming. The record of the past never seems to yield less cause for concern.
The motto for early 21st Century cryospheric science should be “that happened faster than I thought it would.” Wherever we look, either in the past or in the present, we are challenged to keep up – in the ways we measure, theorise, project, and prepare for the future.

*Prof Christina Hulbe is geophysicist in the School of Surveying at the University of Otago in New Zealand
*Dr Christian Ohneiser is a paleoclimatologist in the Department of Geology at the same university.

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