By Bill McGuire

Even as thousands of XR foot soldiers bring London to a halt in the name of climate change sanity, the bad news keeps rolling in. The latest despatches from the climate breakdown front point to the last days of the world’s mountain glaciers and the marvellous ecosystems they support. In an earlier post (Asia – Climate Breakdown’s New Front Line), I revealed how the loss of Himalayan glaciers and ice fields feeding Asia’s mighty rivers could lead to widespread famine as they shrink to little more than trickles. Now, it appears, glaciers in western Europe look likely to suffer the same fate. Hardly surprising really, but nonetheless another nail in the coffin of our stable, pre-climate-breakdown world.

What makes the picture painted by the new study (Modelling the future evolution of glaciers in the European Alps under the EURO-CORDEX RCM ensemble) especially bleak, is that even if we act to drastically curtail greenhouse gas emissions, most of the ice locked up in the world’s mountains will not survive until the end of the century. Given a business as usual scenario, the European Alps will be effectively ice-free by 2100; the winter sports business a distant memory. But even if emissions are slashed, two thirds of the ice will still have melted away in a little over eight decades time. Even more dramatically, whatever action we take on the emissions reduction front fully half of the ice locked up in the four thousand or so Alpine glaciers will be gone within barely thirty years.

A second study (Key indicators of Arctic climate change: 1971–2017) for the first time draws together information from both physical and biological systems to show how rising air temperatures are fundamentally transforming the Arctic and the life it supports as the Earth continues to heat up. As the landmark study reveals, the Arctic region’s long stable climate is now following a path into the unknown. The consequences of this are likely to be widespread and catastrophic, not only for the region itself, but also across the world. What happens in the icy wastes of the north is already affecting the climate at more temperate latitudes, such as Europe and North America. Here, the knock-on effects of changes in airflow at high latitudes are driving persistent weather patterns in both winter and summer that result in extreme weather; big freezes and baking heatwaves. Rapid ice melting in the Arctic is also affecting the Gulf Stream and associated ocean currents and has the potential to bring them to a halt or at least precipitate a major slow down. This, in turn, threatens colder winters around the North Atlantic rim along with rapidly rising sea levels along the eastern seaboard of North America.

So, a message to our XR heroes in the London campaign and those bringing the truth about climate breakdown to cities all over the world. Hang on in there. Our planet needs you now more than ever.

Hothouse Earth, Here We Come

By Bill McGuire

More evidence has come to light to support the thesis that we are on a warming trajectory that will leave our planet unrecognisable from the one upon which human civilisation developed and thrived. Scientists congregated, this week, at Imperial College London for a Royal Meteorological Society meeting, which focused on the Earth’s climate during the Pliocene era, around three million years ago (the last time the Earth had >400ppm of atmospheric CO2). This is the last time that carbon dioxide levels were above 400ppm (parts per million). They are currently 412ppm; up from around 280ppm during pre-industrial times and climbing at two or three ppm a year.

The papers presented at the meeting transport us to a world that is similar to our own in the sense that carbon dioxide levels are comparable, but there the similarity ends. During the Pliocene, global average temperatures were 3°C – 4°C higher than they are today; a seemingly small difference, but big enough to drive changes that make Pliocene Earth dramatically different from that of the 21st century.

Evidence from plant fossils found in Antarctica show that during this part of the Pliocene, beech trees – and maybe conifers – grew on the continent, which had a drastically reduced ice cover surrounded by scrubby tundra. Summertime temperatures were around 5°C compared with minus 15°C – 20°C today. At the other end of the world, Greenland was completely ice-free. The vanished ice at both poles translates into global sea levels that are around 20m higher than they are today.

So, forget the widely touted idea that we can keep the global average temperature rise below 1.5°C or 2°C. It is now clear that the atmospheric carbon levels we have already are compatible – in the longer term – with temperatures 3°C – 4°C higher than they are now. The climate system is relatively slow to respond to change, so it will take some time for temperatures to catch up with greenhouse gas levels. But catch up they will, almost certainly by the end of the century. In other words, whatever actions we take to reduce emissions, we cannot avoid a hothouse planet scenario that will see our society torn apart by a combination of extreme heat, wild weather and catastrophically rising sea levels. And remember, there is still no sign of rising greenhouse levels being brought under control. Given current inaction, carbon dioxide concentrations in the atmosphere could quite feasibly top 500ppm and keep going, dragging global temperatures ever higher.

I hope to God that it never happens, but it is worth keeping in mind that burning most fossil fuel reserves is projected to lead – ultimately – to a global average temperature rise of a staggering 16°C. This would bring the mean temperature of our world to a furnace-like 30°C. This would likely – to all intents and purposes – be an extinction-level event as far as the human race is concerned. Some might say, quite justifiably in view of our appallingly bad stewardship of the planet, good riddance too!

Bill McGuire is Professor Emeritus of Geophysical & Climate Hazards at UCL and author of Waking the Giant: How a Changing Climate Triggers Earthquakes, Tsunamis and Volcanic Eruptions. He was a contributor to the IPCC 2012 report on Climate Change & Extreme Events and Disasters.

An Alarmist’s Guide To Climate Change

By Bill McGuire

First posted on Scientists for Global Responsibility

Have you noticed how the term ‘alarmist’ has been high-jacked? 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 heating argument 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 IPCC (Inter-governmental Panel on Climate Change) of being alarmist. Because every sentence of IPCC report drafts is pored over by representatives of national governments – some of whom are luke-warm 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 last month. 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 Policymakers1 – 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, 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 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 3 metres higher at the end of the century (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). 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 (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).

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 (The IMBIE Team 2018 Mass balance of the Antarctic Ice Sheet 1992 – 2017. Nature, 558, 219-222). 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 (Caesar, L. et al. 2018 Observed fingerprint of a weakening Atlantic Ocean overturning circulation. Nature 556, 191 – 196). 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. 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 (Shakhova N. E. 2008 Anomalies of methane in the atmosphere over the East Siberian shelf. Geophysical Research Abstracts10, EGU2008-A-01526. Abstract), 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 (Whiteman, G., Hope, C. and Peter Wadhams. 2013 Vast costs of Arctic change. Nature499, 401–403), a discrete methane ‘burp’ on this scale, could advance global warming by 30 years and cost the global economy USD60 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 life style; 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

Another week – another bombshell; this time exploding out of the world’s oceans. Covering more than seventy percent of our world’s surface, the oceans form an integral part of the climate system, interacting in many and complex ways with the atmosphere and cryosphere (polar ice). Because they are so closely aligned with the atmosphere they are also intimately linked to climate breakdown and increasingly impacted by it.

More than anything else, as the world has warmed, the oceans have protected us from overwhelming heat that would – by now – have otherwise likely wiped us out. The results of a study published in January reveal that, over the last 150 years, the oceans have absorbed a staggering 90 percent of the heat arising from increasing concentrations of greenhouse gases in the atmosphere. This is the equivalent of the energy produced by between around 1.5 Hiroshima-sized atomic bombs exploding every second over the entire period. Impressive enough; recently, however, the rate of heating has climbed to the energy equivalent of between three and six Hiroshima detonations a second. Another way of looking at it, is that over the last century and a half, the oceans have taken up about one thousand times the annual energy use of global society.

The huge quantities of heat sucked up by the oceans leave just a few percent to heat the land, atmosphere and ice caps – which is very lucky for us. The bad news is that the warmer oceans are starting to drive more powerful, and potentially more destructive, hurricanes and typhoons. Furthermore, ocean heating also drives rising sea levels as the warmer waters expand.

Another study, the results of which were published just this week paints a terrifying picture of the devastating impact of ocean heating on marine life. The authors of this latest study describe ocean heatwaves spreading like the wildfires that, on land, take out vast tracts of bush. In the oceans, instead, great swathes of coral reef, seagrass meadow and kelp forest are being wiped out – along with the sea-life that depends and thrives upon them. Following a similar trend to heatwaves on land, ocean heatwaves have tripled in frequency in just the last couple of decades, raising huge concerns about the survival of marine ecosystems as further heating occurs. Fish stocks, in particular, already seem to be suffering, with global stocks down by at least four percent since 1930, and by as much as 35 percent in some parts of the world.

The bottom line is that, while the oceans are shielding us from the worst of the heating caused by human activities, they can’t continue to do this forever. In addition, as they absorb more and more heat, so the life they contain is coming under increasing pressure. If we continue with business as usual, we will be left with oceans hugely depleted of life, and menus from which fish are permanently excluded. Yet another reason – as if we need one – for net zero emissions by 2025. Let’s do it.

Bill McGuire is Professor Emeritus of Geophysical & Climate Hazards at UCL and author of Waking the Giant: How a Changing Climate Triggers Earthquakes, Tsunamis and Volcanic Eruptions. He was a contributor to the IPCC 2012 report on Climate Change & Extreme Events and Disasters.

The Government that can’t do too little

By Bill McGuire

Monday afternoon (February 25th) temperatures in Trawsgoed peaked at 20.6ºC – the first time that winter temperatures in the UK have ever topped the 20ºC mark. This is, purely and simply, the result of humankind’s impact on the climate. But don’t expect Theresa May and her cronies to pay much attention. When it comes to climate breakdown, this is a government that can’t do too little. While Brexit continues to swamp the news feeds and sucks up all political and social analysis, another crisis spawned by successive Tory governments continues to build, unseen and unheard. In 2006, David Cameron’s fraudulent call to vote blue – go green was rightly laughed off and, thirteen years on, the idea that a conservative government will ever take climate change seriously is still a joke. The latest confirmation comes from a damning letter sent by the government’s own Committee on Climate Change to the UK Minister for Energy & Clean Growth, Claire Perry. I will try and ignore Perry’s Orwelian title – in the context of a regime that continues to push fracking and provide massive fossil fuel subsidies – and focus on the letter’s content.

The gist is this. By almost any measure, the government is failing in its efforts to effectively tackle climate breakdown. Seeking to meet its legal obligation to cut emissions by 80 percent (below 1990 levels) by 2050 – way down on what is needed in any case – it has not met its own targets for 15 out of 18 key indicators for reducing emissions, including in the critical areas of waste and land use, agriculture, transport and buildings. No doubt the government will attempt to grab credit for the one statistic in its favour, which shows that UK greenhouse gas emissions fell, between 2013 and 2018, by 14 percent. We know, however, that ‘home-grown’ emissions are not a fair measure of UK emissions overall, with a big chunk now ‘exported’ to China and other countries that still make stuff. Furthermore, as the CCC reports in its letter, the fall is hardly evidence of pro-active policies. Instead, it mainly reflects the continuing weak economy and changes to the EU Emissions Trading System.

Targets for insulating lofts and walls, and for installing heat pumps were all missed, but this is hardly surprising from a government that in 2016 scrapped plans for all new homes to be carbon neutral. Plans for a quarter of a million electric (including hybrid) vehicles on the road every year are also floundering, with an average of just 48,000 registered annually – less than one fifth of the target. I suppose we should be thankful for small mercies, in that the government rowed back on its ideas – some years back – to privatise the Forestry Commission. Nonetheless, its reforesting initiative is proving to be a dismal failure. On average just seven thousand hectares of new woodland was planted between 2013 and last year, compared to a target annual figure of 25,000 hectares.

In the face of ever more obvious climate breakdown this is a government that can’t even hit its own targets, and doesn’t much care. It is a government that talks the talk on climate change, but one that simply isn’t sufficiently bothered enough about climate breakdown to walk the walk. Remember, these are the same people who – a couple of weeks ago – were lambasting school children for doing what they themselves should be doing. Flagging climate breakdown as an emergency that needs dealing with NOW and getting on with the job. Rather than struggling to meet even its own mediocre emissions reduction targets, the government should be setting far more challenging ones and hitting them. To make this happen, we need to keep up the pressure for nothing less than a war-footing to stop climate breakdown in its tracks. Net Zero Carbon by 2025. Nothing else will do.


It was probably more hope than expectation, but in the early years of the 21st century, it looked as if atmospheric concentrations of the hyper-greenhouse gas, methane had pretty much stabilised. This was good news as the gas has the capability of sending planetary heating into overdrive. In the short term – say a decade or two – methane is capable of warming the planet up to 86 times more rapidly than carbon dioxide. The gas doesn’t hang around in the atmosphere for much more than ten years or so, but then it breaks down into carbon dioxide and water – both greenhouses – which means that its warming influence continues. Even after 100 years, in fact, the global warming potential of the gas is still more than 30 times that of carbon dioxide.


Now, both the hope and expectation seem short-sighted as new research reveals that methane levels in the atmosphere are on the rise again. A new open access paper published by the American Geophysical Union (1) provides evidence for atmospheric methane levels starting to climb once more in 2007 and accelerate significantly for the period 2014 – 17. Such a hike is unexpected and was not factored into the calculations that came up with the emissions reductions framework for the Paris Climate Agreement. Consequently, the probability that global average temperatures will rise far above the 2°C dangerous climate change guard rail is now even greater.


A big concern is that it is not clear where the methane is coming from. There seems to have been an especially significant increase in the gas across the tropics and sub-tropics and at northern mid-latitudes, and more intensive farming and the warming of methane-hosting swamps and bogs have been fingered as possible culprits. Far more worrying is the possibility that chemical changes in the atmosphere, as it warms, might make it more difficult to break down methane. If true, this would be very bad news indeed, because it would mean that this extremely potent greenhouse gas would hang around for longer, thereby significantly increasing its global warming potential.


And there could be plenty more methane to come. Trapped beneath the vast tracts of permafrost at high latitudes are colossal quantities of the gas. 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 one research team 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. A discrete methane ‘burp’ on this scale could, it has been estimated, advance global warming by 30 years and cost the global economy USD60 trillion – a figure close to four times the US national debt. The occurrence of such an outburst is far from certain and there are other issues to consider, including how much methane is absorbed by the ocean as it bubbles upwards. Nonetheless, this cataclysmic scenario provides yet another reason – if more were needed – why we must slash our own emissions to zero as soon as we can.


(1) Very strong atmospheric methane growth in the four years 2014‐2017: Implications for the Paris Agreement


Bill McGuire is Professor Emeritus of Geophysical & Climate Hazards at UCL and author of Waking the Giant: How a Changing Climate Triggers Earthquakes, Tsunamis and Volcanic Eruptions. He was a contributor to the IPCC 2012 report on Climate Change & Extreme Events and Disasters.




Despite the fact that ITV once broadcast a fly-on-the-wall documentary about me called Disasterman, I have always had a fairly positive outlook. Staying optimistic in light of the environmental bombshells published this week, however, is not easy. At times like this it is difficult not to wonder if, whatever action we take, we may already be doomed.

The first bombshell exploded at the weekend, when the results of a major new study (1) revealed that the global population of insects of all types was plunging by 2.5 percent a year. Should this rate of decline continue – and there is good reason to think it could even accelerate – then a quarter of all insects alive today will be gone in a decade. Before 2070, half will have vanished and none will survive to the end of the century. It is impossible to play down the scale of this blossoming catastrophe. Without insects we will starve. Full stop! This would be as near as it gets to an extinction event for the human race, and not one that happens in the dim and distant future, but one that will increasingly impact on our children and their children. As ever, this should not really come as a surprise. We know the cause – a conspiracy of climate change and industrial-scale intensive agriculture. The solutions too, are clear; a complete rethink of our diet, how we grow our food and how we manage our world – for the good of all life, not just our own.

On Tuesday, hard on the heels of the insectageddon bombshell came another, this one in the form of a new report by the UK’s Institute for Public Policy Research (2). This flagged up how the accelerating impacts of climate change and other environmental problems, threatens a collapse of the world’s social and economic systems. Once again, this is hardly news to those of us who have eyes and use them, but the report draws attention to a number of key points; not least the fact that mainstream political and policy debates utterly fail to recognise the problem. It is off the radar and kept there by Brexit, trade wars and comparable issues that pale into insignificance against climate breakdown and environmental degradation. Not only can most policy makers not see the elephant in the room, they are not even in the room.

These two reports are simply the latest in a near continuous torrent of bad news that acts to sap the will. In the face of this mind-numbing deluge, it would be all too easy to throw in the towel; to turn our backs on the environmental crisis that threatens our survival; to plead that it’s just too hard to tackle. But we can’t afford to do this. It is too late now to prevent dangerous, all-pervasive, climate change that will affect every one of us and make the lives of our children and theirs a real struggle. It is going to be tough anyway – that’s now a certainty – but the longer we delay and the slower we are to take serious action, the worse it will be. This is why Extinction Rebellion is calling for a net zero carbon world by 2025. However bad the news gets, this is still something worth fighting for. What choice do we have?

(1) Worldwide decline of entomofauna: a review of its drivers

(2) This is a crisis: facing up to the age of environmental breakdown


Bill McGuire is Professor Emeritus of Geophysical & Climate Hazards at UCL and author of Waking the Giant: How a Changing Climate Triggers Earthquakes, Tsunamis and Volcanic Eruptions. He was a contributor to the IPCC 2012 report on Climate Change & Extreme Events and Disasters.