Coastal freshwater aquifers join the sea

Nazli Koseoglu points out that higher sea levels also mean more saltwater penetration into coastal freshwater aquifers.

Global sea level is rising at an accelerating rate in response to global warming. As temperatures increase, ice growth in winter falls behind ice melt in summer resulting shrinkage of nearly all surveyed glaciers worldwide. According to the U.S. Environmental Protection Agency, decline in ice cover increases amount of freshwater lost to the oceans and has already added about eight inches to the average sea level since Industrial Revolution. The IPCC forecasts [pdf] continuation of this trend in increasing sea levels over the course of this century with 0.4 to 0.8 metre additional increase only if the zero emissions are achieved as a result of historical emissions. On the other hand a more pessimistic  realistic scenario by the World Bank predicts up to 2 metres increase in the sea level assuming global carbon emissions remain unabated. A 2-metre rise in sea levels means an extreme reshaping of coastlines, possible flooding of many low-lying and coastal cities, and severe inundation of several islands.

Next to the well-documented concern for coastal and lowland flooding risk, another yet under-reported impact of sea level rise will be on the freshwater systems. When the freshwater level drops lower than the equilibrium in coastal aquifers, saltwater with higher density, thus pressure, is allowed further in land and salinize groundwater resources. This phenomenon is defined as salt intrusion (Johnson, 2007). Moreover as the sea level goes up beyond tolerable level, the interface between ground and seawater changes and intrusion risk increases, significantly impacting local drinking water availability of coastal communities. Basement and septic system failures and detrition of marshland ecosystems fed by coastal aquifers are other further hazards of the sea level rise associated with coastal aquifers are. How the sea level rise will affect in the coastal aquifers in schematised in the figure below taken from US Geological Survey sources.

coast

Climate-related hazards threaten human-environment systems and their vulnerability increase with amplified exposure. There are wide variety of physical mitigation and social adaptation options of varying effectiveness that could be combined in dealing with reducing the pressure of sea level rise on the coastal aquifers. While physical measures are mainly barriers insulating and recharging aquifers or removing saltwater, socials measures are more about adapting behaviour such as changing or limiting withdrawal patterns from coastal aquifers. However each measure requires a definite level expertise for implementation and comes at a certain capital, operation or opportunity cost to communities at risk that are not always able to afford them [pdf]. This adds up to the immense external costs and injustices of global warming that we do not account for.

coast2

As elaborated in Chang et al. multiple factors affect the vulnerability to salt intrusion in coastal aquifers of different geological characteristics at different altitudes and sea level-groundwater dynamics has a high level of inherit uncertainty due to this complexity. The occasional mismatches in sea level rises at local and global scale also adds to the challenge of determining a rule of thumb indicator or transferable decision support tool to assess vulnerability to sea level rise and type of mitigation measure to be chosen.


nazliNazli Koseoglu is a PhD student from the School of Geosciences of University of Edinburgh, UK. Her PhD looks into the valuation and optimization of water use in Scotland to increase total social return. Prior to her current studies in environmental economics, she received MSc degree in Environmental Studies and BSc in Environmental Engineering. She thinks groundwater systems can not be considered in isolation from rest of the water systems and therefore wanted to contribute Life Plus 2 Meters project to highlight the linkages between sea level rise and groundwater dynamics.

Tides will tear us apart

Emma J. Myatt writes of a future when shopping times depend on the tide.*

Dear Denise,

Congratulations! I cannot believe that by the time you get this, Zane will be fourteen weeks old. I wish there was a way to get news faster – how I miss the internet. I bet you’re an amazing mother. I bet you’re like Mum with a twist, a bit more craziness, a little less planned. You didn’t say much about the birth – not sure how the hospitals are with you but here everyone’s struggling a bit – (we now only get stories in the round-up papers at the end of the week in each town) and I’ve heard about a lack of drugs/pain relief and a total shortage of midwives.

It pisses me off that everyone saw all of this coming, and did nothing. But you know all this, no point in me ranting any more.

I want to meet Zane more than anything in the whole world. I am saving like mad but it’ll still take me years – breaks my heart to think of missing all these early months. I’ll keep doing the lotto – keep everything crossed.

Jake and I are okay. The kids are fine, working hard and hoping to get into the science projects over in the Highlands. There’s been a massive investment in the projects lately and apparently the buildings are huge towering things that you can see for miles. I’ve not been up there, just too much to do here, but I’ve seen pictures. Leo is still good at maths and chemistry, and Lexi’s a physics whizz. God knows where they get it from – not me, as you know – and Jake’s still as into farming and solid earthy stuff as he ever was. I hope they get there. It’s probably the only future I trust at the moment.

We hear stories from Aus, the ships bring papers and news but I dunno how much can be trusted and anyway, by the time they get here everything’s six weeks old. I hear it’s still hot, you are still getting plagues of insects and the fires are nuts, but at least you’re getting more rain than before. I so hope I can see it for myself one day. The latest fares are around £17,500 per person. Jake and I can pull in about half this from anything we need to sell in a good quarter, but it goes, like a finger click, to pay for life and food and everything. We’re stuck, really: if we grew our own we’d survive and not need to buy but then we’d have no money at all. Despite this I’ve managed to save. I’ve £2,000 in the bank, roughly. Jake’s got some stashed in in the farm somewhere (he won’t even tell me in case I let it slip to the gangs) but realistically it’ll be years before we make it.

I miss you so much. Life here’s good in many ways; we’re still healthy and the kids can still learn. Our part of Scotland was pretty empty before as you know so the vanishing land hasn’t had too much impact as yet. But however lucky we feel compared to some, I will never ever forgive myself for not coming with you when the fares were reasonable. I should have listened to Mum. I’ll not go there, I go there every letter and it does me no good.

Has Zane got your eyes? Is he cheeky, like you were? Does he look like his auntie Lynn at all? I bet you’ll be a great mum Denny.

You asked about the house. It’s still here. The water’s about three metres from the door at the highest tides. Last time I wrote it was four, so the rising’s happening quicker than they all said. Nobody will buy it but, amazingly, the government has been good at making flood defences. We’re getting insane storms and the house just gets engulfed by waves. We’d have washed away by now if not for the New Walls they’ve given us. Basically they’re like huge sheets of plastic that have been put up all around the house – we’ve had them about two months now (did I write that we were getting them last time?) They got dug into what was the garden at low tide and they’re higher than the roof. They’re clear, so we can see through, but it’s still like living in a goldfish bowl. If the house goes, we do get compensation but I don’t dare tell you how much – it’s practically nothing. No point moving until it goes, so we’ve stored all the important stuff in the high field in the barn, and the rest is stuff we can live without. The New Walls have doors, all water tight of course, and at high tide we can’t enter or leave. It’s so, so strange. Dad would have hated it and I’m so glad he’s not here. Mum saw a little before she went to the home, but she’s not seen it like this. She’d be heartbroken about the garden so we just don’t tell her or show her pictures.

She’s not doing too well actually Den. I don’t know how much longer she’ll be here. I’m glad you got to say goodbye properly. She has no regrets, just tells me to tell you that you did the right thing. And you did. All that space you have in Australia whilst we huddle on a shrinking rock, climbing higher with every tide, losing more land every week. Estimates say we’ve lost a tenth of the habitable land in the UK. It feels like more.

But we try to stay happy. I sound upbeat, I know. It’s a habit I’ve got into for the kids’ sakes, and it’s hard to stop it.

The truth is though, we’re terrified, Denny. Every day I wake up expecting to be wet. The sea’s come faster than they said. It seems like a dream now when I think of how it was. Every morning I look outside through the weird New Walls and see the world, whitened through sea spray, the farm a little smaller. If the house goes we’ll be moved to one of the new settlements over at Cairn o’ Mount. They’re like council estates from the early 2020s – remember the ones they built during the first housing crisis? Tiny ugly practical things with hardly any space per family. They’re free, that’s about the only bonus. We’ll get allocated one as soon as we become homeless.

Maybe the rising will stop. After all, the ice has all gone, the travel rules have prevented any further air pollution. The limit on electricity will help, as will all the chem bans. But I feel it’s all too late. Like I said, we knew this was coming. Remember the conversations we used to have about ‘doomsday’? There was a guy in the papers last week saying how he felt doomsday had already come – that day when the damage done was too bad to reverse, whatever legislation we make now. I think he’s probably right but we’ve got to hope, right?

I’ll have to go. I can feel myself getting down and I don’t want to do that… in the end I’ll just end up telling you how shit it all is, and how we’re all doomed here and I’ll say again how short sighted I was not to come with you. See? I’m off already. I’ll have to go and get this to the delivery office so it’ll catch the boat on the 12th. I’ll see it all the way, in a bag, making its way to you across all those massive oceans.

Anyway, I’m not down all the time. We keep upbeat. We can still buy whisky, when the tide’s out it’s almost like old times. Ha – do you remember when the garden first got a bit soggy and we thought it was the extra rain or a diverted spring? Then that wave, that just kept on coming? I often think of those early days, when you were still here, when it was all still media hype. I often try to call backwards in time down the years to younger versions of ourselves, to tell them to do something. Nobody would have listened, though. Everyone thought they were just crazy anarchists… crazy people who wanted to cause chaos… remember Paula, and how she stomped off to London with all those petitions? Most of what she wished for has, by necessity, been banned.

I miss all of it.

I want the world back.

I want my sister back. Come home… No, don’t ever come home, it’s not good here and it’s going to get worse. The amount of people and the amount of Hill Houses just doesn’t add up. I hope I’m dead by that time.

I said I wasn’t going to get sad. I’m sorry Den.

I love you, and I love my new nephew, and I’ll keep lottoing and get the rest of us on that boat and come and join you. I can see your farm in my mind’s eye. All that space.

Give Zane a big kiss for me, little sis.

XXXXXX

Lynn.


MyattEmma J. Myatt is a full-time writer, full-time mother, chicken keeper and tutor who also runs a holiday let/writers’ retreat. She writes in every scrap of spare time she can find and has been published on line in various places and in several anthologies. She’s currently working on an anthology of her short stories.

hourofwrites* This vision was an entry in the “Life plus 2m” prompt at Hour of Writes, which carries out weekly, peer-reviewed writing competitions. [Apologies to Joy Devision on the title — David]

It’s about time!

Chris Holdsworth explains how we’ve reached a Catch-22 where inevitable adaptation obviates the need for mitigation.

timeThe single biggest barrier of our understanding and concern about climate change is time. Time is something that dictates everything, from our day-to-day schedules to how our planet regulates itself, but one’s perception of time is entirely subjective. The recent film Interstellar beautifully demonstrated this concept, and it is at the core of the discussion surrounding climate change. Where’s the evidence, why can’t I see it, why aren’t our summers noticeably hotter, why aren’t cities underwater yet? Climate change is to the human eye often invisible. It is planetary processes responding to human activity. The difficulty is that the planetary responses operate on a geological or planetary timescale, something that far exceeds our concept of time. A useful method of illustrating this is to consider the entire history of Earth in 24 hours. Do this and humans first appeared on the planet at 23:58:43, in fact industrialisation only took place seconds ago.

So this is the problem with climate change, a problem that is of our own doing, but which the consequences far-outdate a single generation. However, the fact remains we live in a human world and the impacts of climate change need to be assessed in human terms. Considering a world where sea levels are two metres higher than today is concerning, not least because the science increasingly suggests it could be a possibility by the turn of the century. This is of course because of the complex interconnectivity of our planet’s natural regulatory systems, whereby one change in the colour of a surface can change the amount of energy available to weather systems and geochemical processes. Our planet regulates itself through a multitude of complex feedback processes of which we are forcing and changing at a rate rarely seen throughout Earth history. But again, we live in a human world so we must consider the problems human society will encounter. Professor Brain Cox highlighted this recently:

“The key point is can we respond to it [the clear evidence that our climate is changing]. Do we have the political institutions, the political will and the organisation globally to respond to this challenge, and that worries me immensely. I don’t think we do at the moment.”

This concern is the real danger of climate change. The science involved is not terminal for the Earth, it has survived much worse than us and will most likely long out-live us. Climate change is humankind making our way of life and day-to-day lives much more difficult than they currently are. What Professor Cox highlights is that to change this our governance systems and figureheads need to be motivated and concerned about this issue and put simply, right now they are not.

The idea of sea levels being two metres higher than they currently are has a certain element of catch 22 about it. There would be no reasonable way of ignoring the problem, particularly in government centres like London which would likely be at least partially submerged, because for the first time significant visual evidence of human caused climate change is a problem and seriously threatens our way of life. However, if and when we reach that level of sea level we will likely be beyond the point of easily reversing the change we have set into motion, because of the nature of how our planet regulates itself. It is if you like similar to approaching a waterfall in a boat. Turn the boat a safe distance from the waterfall edge and the financial and physical cost will be minimal, but the longer you wait and closer you get to the waterfall the more difficult it becomes to reverse the direction of the boat until the boat tumbles over the edge and the financial and physical cost exponentially increases and you lose any real control in reversing the direction of the boat.

It is all rather depressing, but infuriating too because governments, particularly following the financial crash of 2008 are overly cautious with government spending for fear of increasing national deficits and decreasing public ratings. However, the longer we delay in truly addressing the causes and threats of climate change the costlier it becomes to everyone, not just government budgets. What is even more tragic is that the threats and causes of climate change present an opportunity to empower and protect individuals, particularly the most vulnerable in society. Small scale, individually owned, energy production, a more regular exposure to the natural world, enhancing the world we live in rather than degrading it. It truly is a tragedy that too many of us are blind to and on current trend will continue to neglect or not even acknowledge until it is too late.

It is perhaps fitting then to finish on the news that at the end of August 2016 a specially commissioned group of scientists came to a unanimous decision that the Earth has now entered a new geological time epoch. An epoch in geological time is shorted than a ‘period’, but longer than an absolute date or event. The criteria for the progression into a new epoch is should geologists in millions of years look back into the rock record at rocks that formed today, is there a notable shift in factors like species numbers, radioactive particles, atmospheric temperatures and rates of erosion. The group found that we comfortably qualify in all of these criteria and hence agreed that the Earth has indeed entered this new period known as the Anthropocene, likely in the mid 20th century upon the dawn of nuclear weapon usage and exponential population growth. What is even more shocking is that many scientists believe we are currently living in the sixth major mass extinction event in Earth history, the famed extinction of the dinosaurs being one of them, because at current rates three-quarters of species could become extinct in the next few centuries.

Despite all of this the question remains, can we respond? Do we have the foresight and will to really tackle this problem head on and save ourselves so much financial and social expenditure in the future? Only time will tell. There is so much potential to change things that will benefit all, but right now the forecast is bleak

HoldsworthChris Holdsworth is a final year undergraduate student at The University of Glasgow where he studies Earth Science. Aside from his studies Chris is regularly involved in public outreach and science communication work, including writing for various online media sources such as Darrow and The Glasgow Insight to Science and Technology. Chris is also the environmental officer on the student representative council (SRC) at Glasgow and sits on the council of this body. He currently lives in Glasgow, but grew up in Teesside, north east England.