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human activity and the destruction of the planet


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Global Heating and Climate Breakdown: a report from Scientists for Global Responsibility (SGR)

Bill-McGuire-2000_cropped

Bill McGuire, Professor Emeritus of Geophysical & Climate Hazards, University College London, argued at the Responsible Science conference that mainstream climate science reports downplay the scale of the threats currently faced, especially from sea-level rise, extreme heat, shutdown of the Gulf Stream, and increased seismic activity. Here he spells out why.

Article from Responsible Science journal, no.2; online publication: 6 July 2020

Also to be found on the website of SGR, of which Bill McGuire is a patron:

https://www.sgr.org.uk/resources/global-heating-and-climate-breakdown


“A very fine line separates alarmism from what a risk expert colleague of mine likes to refer to comically as Compulsive Risk Assessment Psychosis (CRAP) – scaremongering as it is otherwise known. This distinction applies to global heating and ensuing climate breakdown as much as anything else; probably more so given the imminent and desperately serious ramifications of the climate emergency. My concern, however, is that – up until now at least – the message reaching the ears of both the great and the good, and the general public, is simply not alarmist enough. We have alarms for a reason, after all, they save lives. What I mean by this is that it doesn’t set the alarm bells ringing about just how bad things could get as hothouse Earth becomes an ever more likely reality.

In other words, the picture that people see and take on board, of what a broken climate will look like, is not complete. It ensures that the general view of the global heating threat is watered down, one that fails to encompass scenarios involving more deleterious impacts on society. In so doing, a sense of false security is engendered and the ‘call to arms’ to tackle global heating, diminished.

The problem can be traced to the very top. The Intergovernmental Panel on Climate Change (IPCC) undoubtedly has done vital work in building understanding and appreciation of the global heating threat, flagging likely future scenarios, and signalling what needs to be done, and how quickly – to stave off the worst of climate breakdown. Without it we would already be in a very dark place indeed. But there are downsides too.

The IPCC’s periodic reports are conservative and compiled to reflect a broad consensus. This means that they fail to address global heating and climate breakdown scenarios that, although currently regarded by the climate science community as less likely, are – nonetheless – perfectly possible. Because the IPCC reports form the climate bible that drives news stories in the press and broadcast media, this incomplete picture is – inevitably – the one pitched to the public.

The blame cannot, however, be placed at the door of the IPCC. Every report it publishes is scrutinised line-by-line by representatives of all 197 nations and groupings signed up to the 1992 UN Framework Convention on Climate Change (UNFCCC). These include the United States, Australia, Saudi Arabia, Russia and others, who have a history of playing down the climate emergency. As a matter of course, objections are raised to any elements of the text that such signatories regard as pushing too far the envelope of what global heating and climate breakdown might bring. As a consequence, much peer-reviewed climate change science fails to make the reports and, as a consequence, goes largely unnoticed by most of the media and the public.

Nowhere is this more clearly demonstrated than in the area of future sea-level rise. In its 2019 Special Report on the Oceans and Cryosphere (SROCC)1, the IPPC’s worst case likely range for sea-level rise by the period 2081-2100 is 51 – 92cm, with a figure of up to 110cm provided for 2100. In stark contrast, peer-reviewed research, not addressed in the report, forecasts that more rapid break-up of the West Antarctic Ice Sheet could see global sea levels 292cm higher by the end of the century2. Such an order of rise is supported by polar ice melt doubling times at the lower end of the 10-40 year range3 and by a tripling in the rate of Antarctic ice loss between 2012 and 20174. If maintained, such a tripling time of five years would see sea level climbing by around 5cm a year by the mid 2040s.

Another possible consequence of global heating that is underplayed in the IPCC reports is the collapse of the Gulf Stream and associated currents – known in oceanographic circles as the Atlantic Meridional Overturning Circulation (AMOC). In the aforementioned 2019 SROCC report, the IPCC recognises that ‘…the AMOC has weakened relative to 1850-1900….’ but that there is ‘….insufficient data to quantify the magnitude of weakening…’ or to ‘…properly attribute it to anthropogenic forcing.’ The report goes on to say that the ‘….AMOC is projected to weaken in the 21st century….although collapse is very unlikely.’ Other research, reported in a range of peer-reviewed papers is, however, more worrying. The strength of the AMOC has declined by 15 percent since the mid-nineteenth century and is now at its weakest for 1500 years and probably since it last collapsed 11,500 years ago5,6. Shutdown, should it occur, could happen extremely rapidly, perhaps over the course of just a year or two, leading to major cooling of the North Atlantic region and serious knock-on effects on sea level and weather patterns.

In it’s 5th Assessment Report, published in 20147, the IPCC notes that ‘…it is very likely that heat waves will occur with a higher frequency and duration.’ It does not, however, say anything about the terrifying prospect of so-called humid heat waves. These arise when the wet bulb temperature – a measure of the combination of heat and humidity – reaches 35°C. Such conditions, if sustained, are unsurvivable, so that even a fit and healthy human in the shade has only about six hours to live. The required combination of heat and humidity has not been encountered in modern times, but the conditions were almost met in parts of Iran in July 2015. Looking ahead, the second half of the century is forecast to see humid heat waves affecting the Ganges and Indus valleys of South Asia8, the Persian Gulf and China. Most at risk is the North China Plain, where widespread irrigation is predicted to contribute to the occurrence of humid heat waves later this century that could affect up to 400 million people under a business as usual emissions scenario9.

Other elements of global heating and climate breakdown research are omitted from IPCC publications too, or at least soft-peddled. The key question then, is how can this information be made generally available and how can it’s profile be raised so as to present a more complete picture of what a hotter world might look like. Unfortunately, there does not seem to be an easy solution. One way forward might be for the IPCC to openly acknowledge the existence of relevant and important peer-reviewed research that supports non-consensus findings, and to publish this material in addenda to the main reports. This would, or course, require the agreement of the signatories of the UNFCCC, which is likely to prove difficult, if not impossible.

Another way forward could be the establishment of an independently-vetted, non-political website, perhaps validated by national academies of science, on which peer-reviewed research findings not included – for one reason or another – in IPCC publications, could be lodged.

Building a more complete picture – for both stakeholders and the public – of what global heating and climate breakdown could mean, would also benefit from more climate scientists sticking their heads above the parapet and saying in public, what they currently reserve for private conversations. Many climate scientists clearly have an issue with telling it like it is, as high-lighted in a recent analysis10.

This showed that later observations of the climate system (e.g. ice extent and sea-level rise) were typically worse than earlier predictions made by climate scientists, and that key climate indicators were often underestimated. The study also unearthed a general feeling within the climate science community that it needed to give the impression of univocality – speaking with one voice – and a consensus outlook. The analysis also revealed that – when the world is watching – climate scientists worry about how they will be perceived. Taken together, all this means that most researchers working on global heating and climate breakdown tend to play down worst-case scenarios, thereby presenting an unrepresentative picture of their impacts and consequences. What the climate science community should be doing is not making consensus a goal. If it exists, it will emerge in its own right. If it doesn’t, then clear differences of opinion need to be acknowledged and clarified. The time for sweeping inconvenient research findings under the carpet and keeping heads down for fear of reputational damage or derision are long gone. We all have a right of access to the complete picture of the world our children and grandchildren could inherit. Failing to provide this may well mean that the actions we take in this critical decade fall short of what is needed to avoid catastrophic, all-pervasive, climate breakdown.”

 

Bill McGuire’s novel – SKYSEED – an eco-thriller about geoengineering gone wrong, is published in September 2020.

References

1 IPCC 2019, Special Report on the Ocean and Cryosphere in a Changing Climate. https://www.ipcc.ch/srocc/

2 Le Bars, D. et al. 2017 A high-end sea-level rise probabilistic projection including rapid Antarctic Ice Sheet mass loss. Environmental Research Letters 12. https://iopscience.iop.org/article/10.1088/1748-9326/aa6512/meta

3 Hansen, J. et al. 2016 Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 °C global warming could be dangerous. Atmos. Chem. Phys., 16, 3761-3812.

4 The IMBIE Team 2018 Mass balance of the Antarctic Ice Sheet 1992 – 2017. Nature, 558, 219-222.

5 Caesar, L. et al. 2018 Observed fingerprint of a weakening Atlantic Ocean overturning circulation. Nature 556, 191 – 196.

6 Thornalley, D. J. R. et al. 2018 Anomalously weak Labrador Sea convection and Atlantic overturning during the past 150 years. Nature 556, 227-230.

7 IPCC 2013-14 5th Assessment Report. http://ipcc.ch/report/ar5/

8 Im, E., Pal, J. S & Eltahir, E. A. B. 2017 Deadly heatwaves projected in the densely populated agricultural regions of South Asia. Science Advances 3 (8), e1603322.

9 Kang, S. & Eltahir, E. A. B. 2018 North China Plain threatened by deadly heatwaves due to climate change and irrigation. Nature Communications Article 2894.

10 Oppenheimer, M. et al. 2019 Discerning experts: the practices of scientific assessment for environmental policy. University of Chicago Press. 304pp.



 


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An alarmists guide to climate change

This is an article written by Prof Bill McGuire of University College, London and published by Scientists for Global Responsibility, as well as in: Responsible Science journal, no.1; Advance online publication: 14 February 2019.

Below is copied in its entirety from SGR magazine: http://www.sgr.org.uk/resources/alarmist-s-guide-climate-change

ProfBillMcGuire

Prof. Bill McGuire, University College London

“Have you noticed how the term ‘alarmist’ has been hijacked? In the context of climate breakdown, habitat and wildlife loss and other environmental issues, it has become synonymous with scaremongering; with the voice of doom. In certain circles it is frowned upon and judged to be a hindrance to getting the global warming message across. Iconic broadcaster David Attenborough is the latest to express the view that ‘alarmism’ in the context of the environment can be a ‘turn-off’ rather than a call to action. But are such viewpoints justified, especially when our world and our society teeter on the edge of catastrophe? After all, the simplest, most straightforward, meaning of an ‘alarmist’ is someone who raises the alarm. Is this not what we need now more than ever; to be told the whole story – warts and all? The alternative, it seems to me, is to play down the seriousness of our predicament; to send a message that is incomplete, and to conveniently avoid or marginalise predictions and forecasts that paint a picture regarded as too bleak for general consumption. Surely, this is the last thing we need at this critical time?

No-one could ever accuse the Intergovernmental Panel on Climate Change (IPCC) of being alarmist. Because every sentence of IPCC report drafts is pored over by representatives of national governments – some of whom are lukewarm or even antagonistic to the whole idea of climate change – the final versions are inevitably conservative. The closest the IPCC has come to sounding an alarm bell can be found in its latest report Global Warming of 1.5ºC, published in October. Here it warns that emissions must be slashed within 12 years (by 2030) if there is to be any chance whatsoever of keeping the global average temperature rise (since pre-industrial times) below 1.5ºC, and fall to zero by 2050.

Notwithstanding the unlikelihood of achieving net zero global emissions in a little more than three decades, the pace and degree of climate change are about more than just anthropogenic emissions. They are also influenced by tipping points and positive feedback loops; sudden changes in the behaviour of ice sheets, carbon sources and sinks, and ocean currents, which can accelerate warming and its consequences way beyond the expected. Depressingly, but perhaps not surprisingly, the latest IPCC report’s Summary for Policymakers [1] – let’s face it, the only bit likely to be read by the movers and shakers – includes just one brief mention of feedbacks and has nothing at all to say about tipping points. The justification for this appears to be that because it is not possible to assign levels of confidence to such known unknowns, they cannot be included. But it is difficult not to conclude that the real reason is to tone down the threat in order to appease those governments that view climate change as a nuisance that they would like to go away.

The decision to bury concerns over tipping points and feedbacks in the depths of the full report rather than flagging them in the Summary is nonsensical. Touting the critical importance of drastic action while at the same time soft peddling the threat has the potential to backfire, providing the obvious get out: well, if the situation is not so bad, maybe the response doesn’t need to be that urgent. If drastic, life-changing, action is being mooted, people need to know – have a right to know – why. They need to be presented with a complete picture showing how bad things might get – however scary or poorly constrained.

Bringing the potential consequences of tipping points and feedbacks into the equation inevitably transforms perceptions of the dangers we face. Suddenly, climate change ceases to be something vaguely inconvenient that we can leave future generations to deal with. Instead, it becomes far more of an immediate threat capable of tearing our world apart. Take sea level, for example. The IPCC’s 5th Assessment Report, [2] published in 2013 and 2014, predicts – for a worst-case scenario – that global mean sea level could be about a metre higher by the end of the century. Bad enough for millions of coastal dwellers, but nothing compared to what our descendants might experience if a tipping point is crossed that sees the Greenland and/or West Antarctic ice sheets start to disintegrate in earnest. Models that do incorporate this, point to sea level rising far more rapidly. One suggests that the ice loss in Antarctica could occur at a much faster rate than expected, leading to global average sea level being more than 3m higher at the end of the century. [3] Another, based upon correlations between temperature and sea levels during the last interglacial, which ended around 115,000 years ago, proposes that sea level – in theory at least – could climb by as much as 5m by 2100. [4]

Worrying evidence that we might be at a tipping point in Antarctica comes from a very recent study on the rate of ice loss from 2012 to 2017. During this five-year period, Antarctic ice loss shot up threefold, from 76 billion tonnes annually, to a colossal 219 billion tonnes. [5] In total, more than 2.7 trillion tonnes of Antarctic ice has melted in the last quarter century, adding three quarters of a centimetre to global sea level. At the new rate, the contribution over the next 25 years would be 1.5cm. Not enough to worry about in its own right. If, however, the rate of increase is maintained over this period, then the annual rise by 2043 would be close to a catastrophic five centimetres a year. And this is without the growing contribution from Greenland and from the increasing expansion of sea water as the oceans warm.

And there are other causes for serious concern too. None more so than the behaviour of the Gulf Stream and associated currents (together making up the AMOC – Atlantic Meridional Overturning Circulation) that warm north-west Europe and also have a big influence on global weather patterns. In the distant past, surges of meltwater from shrinking ice sheets have caused the Gulf Stream to shut down. Now, it looks as if it might be in danger of doing so again as huge volumes of freshwater from the crumbling Greenland Ice Sheet pour into the North Atlantic, forming a so-called ‘cold blob’.

The IPCC’s official line is that another complete shutdown is ‘very unlikely’, but this is not the same as ruling it out. And there are certainly some worrying signs. The Gulf Stream has slowed by 15 – 20 percent since the middle of the 20th century and is now at its weakest for at least 1600 years. [6] The Gulf Stream has a tipping point, and – evidence from the past shows – can shut down in just a few years when this is crossed. The problem is that no-one knows when – or even if – this will happen. If it does, the ramifications will be sudden and widespread. The North Atlantic region will cool dramatically, particularly across the UK, Iceland and North West Europe, while sea ice will expand southwards (without, it should be emphasised, counteracting the trajectory of climate change). Sea-levels along the eastern seaboard of North America could rise at three to four times the global average rate. Further afield, changes to weather patterns are forecast to include a weakening of Indian and East Asian monsoons, which could have devastating consequences for crop yields. No-one is saying that the Gulf Stream is in imminent danger of collapse. Nonetheless, the threat is not insignificant, and as such should be soberly touted, not wilfully ignored.

Of the many and varied feedback loops and tipping points linked with rapid anthropogenic warming, perhaps the most disquieting involves the vast tracts of permafrost at high latitudes – both on land and beneath the sea. Trapped beneath this frozen crust are colossal quantities of methane, a greenhouse gas that has a warming effect 86 times greater than carbon dioxide. Fortunately, methane has a relatively short residence time in the atmosphere and breaks down to carbon dioxide within a few decades. Nonetheless, major outbursts of methane from the rapidly thawing permafrost are capable of causing climate mayhem with little or no warning. The geographic region of most concern is probably the submarine permafrost that floors the East Siberian Continental Shelf, where an estimated 1400 billion tonnes of carbon, in the form of methane, is lurking beneath a frozen carapace that is thawing rapidly.

According to Natalia Shakhova and colleagues, [7] as much as 50 billion tonnes of this is available for sudden release at any time, which would – at a stroke – hike the methane content of the atmosphere 12 times. According to a study published in 2013, [8] a discrete methane ‘burp’ on this scale, could advance global warming by 30 years and cost the global economy US$60 trillion – a figure close to four times the US national debt. Once again, the occurrence of such an outburst is far from a certainty and there are other issues to consider, including how much methane is absorbed by the ocean as it bubbles upwards. Notwithstanding this, there is a potential danger here that needs to be promulgated rather than hidden away, so that the scale of the climate change threat is clear to everyone.

So – to conclude – be alarmed; be very alarmed. But don’t let alarm feed inertia. Use it instead to galvanise action. For your children’s and their children’s sake, stand up and do something about it. Drastically change your lifestyle; become an activist; vote into power a government that will walk the walk on climate change, not just talk the talk. Or – preferably – all three.”
Bill McGuire is Professor Emeritus of Geophysical and Climate Hazards at University College London and a co-director of the New Weather Institute. His current book is Waking the Giant: how a changing climate triggers earthquakes, tsunamis and volcanoes. He is a signatory of an academics’ letter in support of the School Climate Strike.
References

1. IPCC (2018). Global Warming of 1.5°C. Summary for Policymakers. http://report.ipcc.ch/sr15/pdf/sr15_spm_final.pdf

2. IPCC (2014). Fifth Assessment Report. http://ipcc.ch/report/ar5/

3. Le Bars D. et al (2017). A high-end sea-level rise probabilistic projection including rapid Antarctic Ice Sheet mass loss. Environmental Research Letters, vol.12.

4. Hansen J. et al (2016). Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 °C global warming could be dangerous. Atmos. Chem. Phys., vol.16, pp.3761-3812.

5. The IMBIE Team (2018). Mass balance of the Antarctic Ice Sheet 1992 – 2017. Nature, vol.558, pp.219-222.

6. Caesar L. et al (2018). Observed fingerprint of a weakening Atlantic Ocean overturning circulation. Nature, vol.556, pp.191-196.

7. Shakhova N.E. (2008). Anomalies of methane in the atmosphere over the East Siberian shelf. Geophysical Research Abstracts, vol.10, EGU2008-A-01526. Abstract.

8. Whiteman G., Hope C., Wadhams P. (2013). Vast costs of Arctic change. Nature, vol.499, pp.401–403.


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Disappearing arctic polar ice cap – can this affect the Gulf Stream and the Jet Stream?

In Chapter 1 of my book, I provide evidence that the arctic ice is shrinking.  This is shown graphically in Figure 14 (page 34), which I reproduced, with acknowledgements to Andy Lee Haveland.  Because the size of the arctic ice varies throughout the year, and summer to winter, it is important to take measurements throughout the seasons of the year.

The figure below, published in my book with permission, gives an idea of what has been happening between 1979 and 2016.  arctic-death-spiral

Each colour represents a different month of the year and the difference in the size of the ice throughout the year shows how much it has shrunk during the period 1979-2016.  The stark difference between 1979 and 2016 can be seen best at the top of the graph.

Now, NASA has produced a time-lapse video showing the movement of the ice as it pulses through the seasons.  The video is posted on YouTube with this description, “Arctic sea ice has not only been shrinking in surface area in recent years, it’s becoming younger and thinner as well.”  The video can also be seen on the following website:

NASA releases time-lapse of the disappearing Arctic polar ice cap

This last winter (2017-18) has been very much colder in the UK and other parts of Europe and this has led to some people denying that global warming is happening.  The crazy thing is that, whilst Britain was in the grip of a lengthy period of freezing weather and large falls of snow, at the north pole it was warmer than usual, reaching melting point in some places, with temperatures up to 20 degrees higher than normal.  Similar temperature anomalies were also reported for some of the US and Canada.

The reality is that this phenomenon is all part of the unstable weather patterns that are being caused by climate change.

Now, in the latest issue of New Scientist (No. 3169, 17th March 2018), Colin Barras describes new research, which might suggest that changes in the North Atlantic current (the northern part of the Gulf Stream), could result in a shut-down, leading to even greater sea-level rise on Atlantic coasts and more intense droughts in Africa.

https://www.newscientist.com/article/mg23731693-200-polar-melt-may-shut-down-the-atlantic-current-that-warms-europe/

Marilena Oltmanns and her colleagues have studied the salinity of sea water and its temperature in the area just south of Greenland (Irminger Sea) between 2002 and 2014.  They found that, in summer, the sea had much warmer temperatures and lower salinity.  This would suggest that fresh water (melt from Greenland and the Arctic) is flooding into this area and affecting the currents and convection process.  This was more likely to happen after particularly mild winters.  In 2010-11, conditions were mild, resulting in an accumulation of fresh water in the sea, 40% of it still there even after the end of winter.  These findings are reported in Nature Climate Change, doi.org/cmbw.

Oltmanns believes that, if several warm years occur in succession, there would be a build up of fresh water, impeding the process of convection.  This might result in a shut-down of the North Atlantic current.  This might bring about the end of the North Atlantic’s relatively mild climate and the ameliorating effects of the Gulf Stream.

Other writers and researchers are proposing other impacts too, as far reaching as Africa and South America, though at this time much of it is still speculation.

Further information about the North Atlantic current can be found in Wikipedia, from which the following diagram has been taken.

2000px-North_Atlantic_currents.svg

 

Could this mean that the prolonged freezing period experienced in the UK and Europe last winter could become the norm?

Since writing the above, I have come across a review of scientific articles about the state of the Arctic ice cap, written by Vanessa Spedding.  It can be found on the Scientists for Global Responsibility website, as follows:

http://www.sgr.org.uk/resources/state-arctic-heightens-focus-climate-policy

The main conclusion of this review is that the presence of a summer ice-free Arctic can be an indicator of how well the world is sticking to the 1.5 degree Paris Agreement target for global warming.  There is a very low chance of an ice-free Arctic at 1.5 degrees but at 2 degrees, the chance rises to 39%.  At 3 degrees, 73%.  Full details of this work can be seen in an article by Screen and Williamson at:

11. Screen JA, Williamson D (2017). Ice-free Arctic at 1.5 °C? Nature Climate Change, vol.7, pp.230–231. DOI: 10.1038/nclimate3248.  https://www.nature.com/nclimate/journal/v7/n4/full/nclimate3248.html

Another 15 articles are cited in Spedding’s review. One of them, from Prof. Jennifer Francis of the Institute of Marine and Coastal Sciences at Rutgers University in the USA, suggests that there is a link between a warming Arctic and a disrupted jet stream, with effects on Northern hemisphere weather patterns.

Now, in August 2018, a report in The Guardian suggests that the oldest and thickest sea ice in the Arctic has started to break up for the first time ever, opening waters north of Greenland that are normally frozen the year round – an area that is often called “the last ice area”.  It is believed that this has occurred because of the abnormal heatwave in northern Europe in the summer of 2018. In the past, the ice in this region has packed together and is over 4 metres thick, with ridges up to 20 metres.

Full details about this and other concerns of climate scientists can be seen at:

https://www.theguardian.com/world/2018/aug/21/arctics-strongest-sea-ice-breaks-up-for-first-time-on-record?CMP=twt_a-science_b-gdnscience

ANTARCTICA

As regards Antarctica, the situation is just as grim, though different from the Arctic. A British-led study, using satellite tracking, showed that a region of ice the size of Greater London vanished from the edge of Antarctica between 2010 and 2016.

The 1,463 square kilometres of underwater ice at the base of the Antarctic ice sheet melted under the influence of warm ocean water currents. Scientists demonstrated how the massive ice sheet is retreating as its edges, fed by a multitude of glaciers, are eroded.

See: https://www.aol.co.uk/news/2018/04/02/antarctic-ice-area-the-size-of-london-lost-in-six-years/?ncid=webmail

The lead researcher, Dr Hannes Konrad, from the University of Leeds, said: “Our study provides clear evidence that retreat is happening across the ice sheet due to ocean melting at its base, and not just at the few spots that have been mapped before now. This retreat has had a huge impact on inland glaciers, because releasing them from the sea bed removes friction, causing them to speed up and contribute to global sea level rise.”

The biggest changes were seen in West Antarctica, where more than a fifth of the ice sheet had retreated across the sea floor faster than the general pace of deglaciation.

The findings have been published on 2nd April 2018 in the journal Nature Geoscience. See: https://www.nature.com/articles/s41561-018-0082-z

Previous studies had indicated an expansion of sea ice in the antarctic region but this latest study used grounding lines as indicators of ice-sheet instability.

 

Further posts will be added here as they emerge.