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John Mason

John Mason graduated in geology from Aberystwyth University in 1985. He went on to undertake research on ore genesis and supergene alteration in the metalliferous mining districts of North and Central Wales, leading to an M Phil and a number of key papers. He also worked for a time in mineral exploration with the British Geological Survey and then the private sector. His interest in climate came via investigating severe weather events and their aftermath and seeing the massive changes that past climate shifts have brought to the Welsh landscape. When not doing any of the above, landscape and weather-photography plus sea-angling keep him occupied.


Recent blog posts

The History of Climate Science

Posted on 5 June 2020 by John Mason


The fact that carbon dioxide is a 'greenhouse gas' - a gas that prevents a certain amount of heat radiation escaping back to space and thus maintains a generally warm climate on Earth, goes back to an idea that was first conceived, though not specifically with respect to CO2, nearly 200 years ago. The story of how this important physical property was discovered, how its role in the geological past was evaluated and how we came to understand that its increased concentration, via fossil fuel burning, would adversely affect our future, covers about two centuries of enquiry, discovery, innovation and problem-solving.

This version (June 2020) supercedes the original April 2013 article, since a lot more has come to light about the work done in the 1850s-early 1860s and the important role of Eunice Foote. Katharine Hayhoe is particularly thanked for helpful discussions on that topic.

For larger versions of all timeline graphics, please click on them (they will each appear in new browser windows).

Two centuries of climate science - the timeline

Climate Science - the complete timeline, created by jg. Click on graphic for larger version.

In the beginning...



Ynyslas, western Wales – a place made by climate change

Posted on 31 October 2019 by John Mason

Ynyslas, on the Cardigan Bay coast of Wales, is a place well-known for its extensive, shingle spit-fronted sand-dunes, its hinterland of estuarine saltmarsh-flats and, seaward, its golden sandy beach, complete with a several thousand year-old submerged forest. The place gets some 250,000 visitors a year. Taking all of those factors into account, and that Ynyslas is also a direct product of actual climatic changes that occurred in the geologically-recent past, its tale was ripe for the telling, so that's just what I did. I wrote a book about it.

book  cover

The Making of Ynyslas is a climate science book with a difference. It is an account of how climate change brought one well-loved modern landscape into existence, but in doing so, destroyed another. Covering the last 25,000 years, since around the time of the Last Glacial Maximum, the story involves the details of deglaciation as the world's great ice-caps retreated polewards and seas rose, sometimes gradually and sometimes rapidly, by some 125 metres. In doing so, large areas of land were drowned: on a human time-scale, the changes would be permanent. On a geological time-scale, over hundreds of millions of years, the area now occupied by Cardigan Bay has variously been dry land or underwater on several occasions. In addition to climate change we have to consider the area's tectonic evolution over such lengthy time-frames, which are outside of the scope of the book, covering as it does the latest Pleistocene and the Holocene Stages of geological time.

Lumped together, these two stages make up the latter part of the Quaternary System, which began, following the Pliocene, 2.58 million years ago. The Quaternary represents a diversion away from the norm of the previous tens of millions of years, in that it featured regular and cyclic advances of ice-sheets, equatorwards from the Polar regions. For long stretches of geological time prior to the mid-Cenozoic, say from before some 35 million years ago, Polar ice was not a regular feature on the menu at all. So the changes from that climate state to the alternating glacials and interglacials of the Quaternary were, by definition, profound. But in order to understand how such changes came about, it is first necessary to look at past times when Earth has had an Icehouse climate. It's not a particularly common climate state over geological time and perturbations to the Slow Carbon Cycle have had a hand in every such switch.



Rebellious Times

Posted on 29 April 2019 by John Mason

The Extinction Rebellion protests of 2019 and their naysayers: analysis

It can sometimes seem a lonely road to walk. Voices in the wilderness: a plucky band of writers doing their best to explain the science of climate change, anxiously watching as the countdown-clock ticks away. Producing carefully-written, fully-referenced content, only to watch people turn over and go back to sleep. Facing condemnation, derision, ridicule, from those to whom any notion of deviation from Business as Usual is anathema. Yes, the lot of the climate change campaigner has indeed felt like a lonely road at times. But not any more.

Something extraordinary has happened. People have woken up. It reminds me in a sense of the closing chapters of Tolkein's Lord of the Rings, in which the consistently laid-back and predictably passive hobbits suddenly arise en-masse, to put a swift end to Saruman's occupation and wanton destruction of The Shire. In Tolkein's narrative, the hobbits have to fight a battle, sacrificing some of their own in the process of securing a better future for their people. It was how things tended to be done in Middle Earth.

Switch to the UK in April 2019 and it's not swords and shields but locks, glue, dance and song. The extraordinary protests by the new group, Extinction Rebellion, have brought not only climate breakdown into the limelight, but also biodiversity-loss, pollution and the myth that you can have infinite growth on a finite planet. Over the same period, vast numbers of schoolchildren have undertaken strikes and organised their own demonstrations. Swedish student Greta Thunberg has admonished administration after administration on her tour of European capital cities. Bank of England Governor, Mark Carney, starkly warned companies that if they don’t adjust to the reality of global warming, they will simply cease to exist. To top all of that off, David Attenborough delivered his bluntest warnings to date in a lengthy and compelling documentary - “Climate change: the facts”. In the light of all these developments, it almost feels as if I can put my feet up!

Of course, neither I nor we will put our feet up: if you don't hear from some Team-SkS members for a while, you can guarantee they are still busy on things climate-related, in various other ways. We know there will always be political opposition to climate science; the usual suspects will not stop peddling their contrarian talking-points and they will not go unopposed.



Welcome to the Pliocene

Posted on 10 August 2018 by John Mason

The whole story in a table....

The graphic below (click on it for a large version) is adapted from a table in the supporting information from a newly published paper in Proceedings of the National Academy of Sciences (PNAS). Trajectories of the Earth System in the Anthropocene, as the paper is entitled, looks at several climate states - the present day, the mid-Holocene, the relatively warm Eemian interglacial and, heading back a bit further into geological time, the mid-Pliocene and mid-Miocene. Data are from palaeoclimate studies. The right-hand column assesses our chances of stabilising our climate at these states in the coming decades. In some cases, it is already too late - we have gone beyond the physical parameters that support such climates:

Data details: atmospheric CO2, temperature anomaly relative to the pre-industrial era and sea-levels relative to now measured and from palaeoclimate records. The graphic, created by "JG", is adapted from Table S1 from the paper's supporting information section, available here. Data sources are fully referenced.



Dear Mr President 2.0: the discovery of the Greenhouse Effect - in Tweets

Posted on 3 April 2017 by John Mason

Here's another in our occasional series where we explain aspects of climate and planetary science in tweets. For this one, we've picked the history of the discovery of Earth's greenhouse effect, a topic we covered in detail a few years ago in The History of Climate Science. If there's a single take-home point, it's simply that we have known about Earth's greenhouse effect and the important role of carbon dioxide for a long time. A very long time. An awful lot longer than some people seem to realise.

Some climate change contrarians, when presented with facts, simply dismiss them as an "appeal to authority". Brexit enthusiast Michael Gove is so famous for stating, “people in this country have had enough of experts”, that if you type his name into Google the second thing that appears in the dropdown below is "experts". But you can bet your bottom dollar that the moment he needs specialist advice in his private life, he goes and finds a specialist. We all do.

Talking of specialists, many have come and gone in the decades before the present generations of scientists and long before the first automobiles appeared in numbers on our roads, some remarkable things had already been accomplished. This post is something of a celebration of such accomplishments and the people who made them possible.



Nobody really knows: a Trumpworld dreamscape

Posted on 29 March 2017 by John Mason

“I'm very open-minded. I'm still open-minded. Nobody really knows. Look, I'm somebody that gets it, and nobody really knows. It's not something that's so hard and fast”

Donald Trump on climate change, during an interview on Fox News Sunday, 11th Dec 2016

It had been a long day. The rain fell incessantly as a gale rose from the south-west. I had read a couple of new peer-reviewed papers as one attempted distraction, chatted online with a few fellow climate campaigners as another, argued with a few of the usual suspects and their followers as a third, then finally settled down into a prolonged stint of editing a book-chapter. Darned word-limits!

After a late supper I had a quick trawl through Facebook, scrolling past the photos of people's cats, interspersed with a multitude of political posts, almost entirely concerning either Trump or Brexit. You don't see much else these days. There was the odd one mentioning Arctic sea-ice (still at a record low and now beginning to fall again) and I put right a commentator who was arm-waving about the Antarctic, but who hadn't bothered to check the latest data. Oh well. I took a quick look outside. The wind had veered north-west and dropped. Ragged clouds drifted past the Moon. The air felt unusually warm but damp. Owls called in the unseen distance, whilst closer by, the enthusiastic croaking of frogs reminded me that spring had officially arrived. "Pruitt, pruitt, pruitt", they went, on and on. "Brexit", said another, quite distinctly. "Poor thing", I thought. "It must have a sore throat". I closed the door and turned in with a favourite book, but I was knackered. Before I was halfway from Bree to Rivendell, dodging Black Riders, reality had drifted away....



To tweet or not to tweet at Donald Trump? That was the question!

Posted on 8 March 2017 by BaerbelW

Knowing Twitter to be the prefered means of communication for the current POTUS and that he “may” have a thing or two to learn about climate science, John Mason recently set out to explain the carbon cycle in a series of 49 tweets in a language we hoped Donald Trump would be able to grasp.

As John explained: “I often wonder if a lot of climate change communication follows formats that may be unattractive to some people. Lengthy posts complete with explanatory graphics are appreciated by many, but others simply may not have the time to work through them for all sorts of reasons. Yet, this should not exclude them from accessing information. So regardless of whether Trump read the tweets or not, I wanted to proceed with this as an experiment in making climate communication available to a wider demographic. The simpler the framing of information, the more quickly it may be scanned and absorbed. I picked a fairly complex aspect of planetary science - Earth’s Carbon Cycle - and set out to simplify it whilst keeping it consistent with what the science says.

So, on February 28, the tweets started to go out on Twitter in a little tweet storm:


A good two hours later the final tweets were sent:




Dear Mr President: another message from across the Pond

Posted on 28 February 2017 by John Mason

The Carbon Cycle in 49 tweets

There seem to be a fair number of communications being sent to the White House right now. On Thursday 23rd February, The Hill reported that "Climate sceptics ask Trump to withdraw from UN agency". The "agency" in question being the U.N. Framework Convention on Climate Change and the name behind the letter being Richard Lindzen and some 300 of his buddies. This bunch of 300 signatories has something of a resemblance to those behind a January 2016 letter to NOAA, again with Lindzen involvement. Both lists read like a who's who of the usual suspects. Some sections could almost have been copied and pasted from the DeSmogBlog database of climate misinformers.

That aside, Lindzen and friends have missed an important point in this instance. Trump's preferred style of written communication is The Tweet. A series of long paragraphs is unlikely to garner the desired attention. Sometimes, it is necessary to communicate to people in their own language.

So let's try just that, in explaining to President Trump the importance of and the hazards associated with Earth's Carbon Cycle. Unlike Twitter though, this post reads in a user-friendly way, from top to bottom. So, without as much as a smidgen of FAKE NEWS, here we go:

@RealDonaldTrump 1/49

We want to tell you all about the Carbon Cycle. It helps make this planet great, so long as you don't MESS WITH IT.

@RealDonaldTrump 2/49

The Carbon Cycle is in two parts. One fast & one slow. They are different things because of the stuff they involve.

@RealDonaldTrump 3/49

The Fast Carbon Cycle involves plants. They feed on CO2 & make sugar. They keep it in their roots, stems and stuff.



Dear Mr President-elect: a message from across the Pond

Posted on 29 November 2016 by John Mason

Dear Mr President-elect,

On 6 Nov 2012, at 11:15 am, you tweeted:

“The concept of global warming was created by and for the Chinese in order to make U.S. manufacturing non-competitive.”

We'd like to take you on a quick tour back through the ages, because the early understanding of Earth's climate - and the role that carbon has to play in it - came from the West, not the East. Let's run through it quickly.

In 1800, British astronomer William Herschel first measured the heat that occurs in the warm – now known as infra-red (IR) – part of the spectrum. In 1824, French engineer Jean Baptiste Joseph Fourier calculated that Earth should be colder than it is, at its orbital distance from the Sun. Today, it is common knowledge that outgoing IR radiation is emitted by the Earth's surface in response to heating by the Sun. But Fourier was the first to figure out that the IR was being slowed down during its journey back out to space. The air, he said, must act as a form of insulating blanket, keeping the planet warm. Smart guy.

This was just two years before Samuel Morey patented the first internal combustion engine.

In 1861, Anglo-Irish physicist John Tyndall observed that some atmospheric gases were transparent to IR radiation. But he found that others, like water vapor and carbon dioxide, were powerful IR absorbers. He was the first to propose that changes in the amount of carbon dioxide in the atmosphere could influence the Earth's climate. In 1896, Swedish scientist Svante Arrhenius took it further. He made the first detailed calculations to see what a doubling of carbon dioxide levels might do to temperatures. His answer was a 5-6°C increase in the average global temperature. His ‘hot-house theory’ was set out for the first time in 1908 in his popular book ‘Worlds in the Making’.

In 1909, American astronomer Andrew Douglass developed the techniques of studying tree-rings and was the first to find the connection between tree ring widths and climate. In 1931, American physicist E.O Hulburt ran calculations to determine the effect of doubling carbon dioxide with the added burden of water vapor. His figure? 4°C of warming. In 1938, English engineer Guy Callendar discovered evidence of a warming temperature trend in the early twentieth century. He also found that CO2 levels were increasing and he warned that over the coming centuries there could be a climate shift to a permanently warmer state.



A Rough Guide to Rainfall, Run-off and Rivers

Posted on 19 January 2016 by John Mason

Introduction: a moment of realisation. July 2001, North Wales, UK

Pulling onto the side of the forestry road the air was thick with a single smell – that of mangled conifer wood. I locked the Land Rover and scrambled down to the river. It was a familiar route, an anglers' path that weaves its way cunningly for several tens of metres through steep, dense undergrowth. But something was different this time. The vegetation ended abruptly some way before it should have done. Where there had been soil, grass, rhododendron and bramble, naked rock now gleamed in the sunshine. Continuing down, I saw that the river, back down to its normal level, had an unusually clouded, milky look to it. Upstream was a prominent bluff of rock, several metres higher than its surroundings, on top of which a large Douglas Fir tree stood. It was still there, but the first few metres of its trunk were thickly and tightly wrapped with branches and tree trunks, their bark stripped away. Scrambling up the tight cone of flood-borne debris, I turned and looked down. It was at least ten metres from the top of the debris-wrap down to the water.

July 2001, North Wales

above: aftermath of a huge flash flood in July 2001, Afon Mawddach, North Wales. The figure perched on the left-hand side of the debris-wrap is a good 2 metres tall. Photo: author.

Two days before, a severe thunderstorm had affected the region. Had the area been well-populated, the resulting flash floods would have made the national headlines. Houses would not just have been flooded: some would have been swept away. It served, in the author's case, to raise an awe-struck awareness of just what can happen when the required meteorological ingredients come together. You cannot beat seeing things for yourself.

Why a rainfall primer?

So: what makes the difference between an ordinary wet day and an extreme rainfall? Judging by the often confused and contradictory comments from online discussions in the wake of the late 2015 floods, this seems as good a time as any for a primer - the three R's of flooding if you like. Rainfall, run-off and rivers. It is aimed primarily at UK readers and a lot of the illustrated examples are from Wales, because that's where I live and they are things that I have seen for myself, but the same principles apply in many parts of the world, outside of the Tropics. Rainfalls in extratropical parts of the world have a complex set of causative factors and effects. This post takes a more detailed look at both. It is by necessity long, because you cannot realistically deal with complex topics in a few soundbites, so it has been divided into sections, linked to by the seven bookmarks below.



December 2015 Floods: a floating postcard from the UK

Posted on 16 December 2015 by John Mason


The last few weeks of 2015 will be remembered for a long time in some parts of the United Kingdom for all the wrong reasons. Flooding, a word which for some has truly become the F-word. It has brought with it destruction and misery, accompanied by yet another round of smashed rainfall records, including national ones that have only stood since 2009, when many of the same communities in NW England suffered cruelly. Copenhagen and Cockermouth: Paris and Patterdale. The politicians thrash out their deals while on the ground the lives of ordinary folk are again put on hold.  But how, and why did it happen again so soon after the last time? Let's try and get through the fog. There's a lot of nonsense that gets repeated following flooding disasters in the UK. It's a bit like the myths about climate change that this website was set up to counter: there are flooding myths too. So let's take a primer in why floods occur, look at what happened last weekend in the north of England - it was an Atmospheric River that was responsible - then examine some of the myths.

pooley bridge (built 1764)

Above: the historic and much-photographed Pooley Bridge, near Ullswater and built in 1764, twelve years before America declared independence, was severed by the December 2015 floods. Photo credit: Cumbria Crack - a local news site that has pages of detailed reports on the floods for those who want to learn more. A revealing video of the afflicted old bridge, including before and after shots, is on Youtube here.



The importance of good climate communication: a recent Arctic example

Posted on 23 July 2015 by John Mason

Here's the abstract of a new paper in Nature Geoscience on Arctic sea-ice volume:

Changes in Arctic sea ice volume affect regional heat and freshwater budgets and patterns of atmospheric circulation at lower latitudes. Despite a well-documented decline in summer Arctic sea ice extent by about 40% since the late 1970s, it has been difficult to quantify trends in sea ice volume because detailed thickness observations have been lacking. Here we present an assessment of the changes in Northern Hemisphere sea ice thickness and volume using five years of CryoSat-2 measurements. Between autumn 2010 and 2012, there was a 14% reduction in Arctic sea ice volume, in keeping with the long-term decline in extent. However, we observe 33% and 25% more ice in autumn 2013 and 2014, respectively, relative to the 2010–2012 seasonal mean, which offset earlier losses. This increase was caused by the retention of thick sea ice northwest of Greenland during 2013 which, in turn, was associated with a 5% drop in the number of days on which melting occurred—conditions more typical of the late 1990s. In contrast, springtime Arctic sea ice volume has remained stable. The sharp increase in sea ice volume after just one cool summer suggests that Arctic sea ice may be more resilient than has been previously considered.

OK, let's pick this apart. Arctic sea-ice volume is the trickiest of the sea-ice variables to measure. Extent and area are by contrast straightforward. Volume depends on the survival of multi-year ice in any melt season. A pronounced melt season, like 2012, sees some of the multi-year ice lost. But if any of the ice that didn't melt in 2012 makes it through the 2013 season, you are going to get a volume increase. The authors state that they observed 33% more ice volume in autumn 2013 relative to the 2010-2012 mean. They go on to state that in 2014 there was 25% more ice volume relative to 2010-2012 – in other words it dropped again. That shows up on the following ice thickness distribution plot: the thickest ice is in red. Big red blob for 2013, much smaller one for 2014.

ice thickness map

Such observations are reasonably consistent with PIOMAS:

arctic sea ice volume - PIOMAS



Spoiled ballots, spoiled views: an election snapshot from Powys, Wales, UK

Posted on 25 May 2015 by John Mason

It's a funny thing. One of the most viral news items concerning the UK General Election on May 7th 2015 came from my constituency of Montgomeryshire. Apparently, someone took the time and trouble to draw a remarkably detailed sketch of a penis in the box that they would have otherwise crossed had they been voting for the incumbent Conservative MP, Glyn Davies. In other headlines, three high-profile party leaders resigned within an hour of one another the following morning but everybody turned over and went back to sleep on that one.

I hasten to add that the artwork had nothing to do with me. I voted for one of the other guys – tactically, which in the context of Glyn's significantly increased majority turned out to be a wasted vote. I should have voted with my heart – for the Greens or Plaid Cymru. Unlike the other parties, at least I can state that I have met the leaders of the latter two in person and have found them to be – well, real, passionate and principled people, as opposed to the used car salesmen stuffed into suits to look “respectable”, that tends to be the norm over here.

So, what has this to do with climate change, readers may well be asking? Quite a lot in fact. What troubles me about the outcome of Election '15 is that voters, like turkeys vaguely approving the advent of Christmas, seem to have voted for more Business As Usual. But they have done so in a political atmosphere so clouded with media-served misinformation that it is hard to know where to start with the debunking. So let's put UK politics to one side now and stick to our speciality: dealing with another channel of misinformation, that related to global warming. Take a look at this letter, from the latest issue of the County Times, a weekly newspaper that covers Powys, the larger local authority area of which Montgomeryshire is a part:

letter, County Times



The UK winter of 2014-15: another Tabloid FAIL

Posted on 26 March 2015 by John Mason

Daily Express 10/10/2014

Above: Express, October 10th 2014

Introduction: the first ominous signs

“Winter 2014 set to be 'coldest for century' Britain faces ARCTIC FREEZE in just weeks”.

That was the Daily Express headline on October 10th 2014. Quoting self-styled "independent" long-range weather forecaster James Madden, it warned of an icy apocalypse on the way:

“A number of potentially very cold periods of weather and major snow events are likely to develop throughout this winter across large parts of the country, in particular, throughout the latter part of December and into January. The worst case and more plausible scenario could bring something on a similar par to the winter of 2009/10, the coldest in 31 years, or an event close to 2010/11 which experienced the coldest December in 100 years.”

Snow-enthusiasts will recall both January and December 2010 with fondness. The whole of the UK was affected: in Mid-Wales where I live snow covered local beaches above the high water mark and there were copious large ice-floes bobbing about on the Dyfi Estuary. For a while in the days following December 18th 2010, even low-lying towns like Machynlleth were blanketed in thick snow up to a foot deep. 2009-10 was the 59th coldest winter (meteorological period December/January/February) on the Central England Temperature (CET) record which goes back to 1659. 2010-11 was 112th, losing out due to milder conditions arriving in the New Year, although December 2010 at a shocking -0.7C was the second coldest December in the monthly CET record.

That sets the scene. As readers might have guessed, this post is about the UK tabloid press and its ridiculously sensationalistic weather-stories. Firstly, here is the timeline, and brief descriptions of the very severe past winters referred to in the forecasts.


Not to be outdone, the Daily Mirror had the following message for its readers on October 29th:



The cause of the greatest mass-extinctions of all? Pollution (Part 2)

Posted on 19 March 2015 by John Mason

Part Two: the Siberian Traps and the end Permian mass extinction


With more than 90% of all marine species and 75% of land species wiped out, the end Permian mass extinction was the worst biosphere crisis in the last 600 million years. The extinction was global in reach: almost all animals and plants in almost all environmental settings were affected. An idea of the severity can be visualised by considering that the time afterwards was marked by the beginning of a coal gap lasting for ten million years: coal-forming ecosystems - i.e. forests - simply did not exist for that time.

The onset of the mass extinction coincided with the main part of the eruption of the late Permian Siberian Traps Large Igneous Province (LIP), 251.9 million years ago (Ma). It contains what may be the largest known volume of terrestrial flood basalt in the world. Estimates vary but they start at volumes of at least 3 million cubic kilometres of igneous rocks that were erupted onto and intruded beneath the surface during the event. There are some much larger volume estimates that take into account "missing" erupted rocks since eroded away and the likely ratio of intruded to erupted rocks. Either way, as eruptive cycles go this was one of the biggest ever.

At the same time, there was a dramatic perturbation to the global carbon cycle, involving the injection of enough carbon dioxide to the atmosphere to triple the pre-existing levels and raise temperatures substantially. There were severe problems with other pollutants: acid rain, soil erosion, algal blooms and ocean acidification and anoxia all took a dramatic toll on life on land and in the seas.

That the Siberian Traps eruptions, the greatest of the Big Five mass-extinctions and carbon cycle havoc all happened in broadly the same geological timezone suggests they may not be unrelated. However, coincidence is not necessarily cause. For example, what if the extinction occurred a million years before the Traps were erupted?



The cause of the greatest mass-extinctions of all? Pollution (Part 1)

Posted on 19 March 2015 by John Mason

Part One: Large Igneous Provinces and their global effects


A mass extinction is an event in the fossil record, a fossilised disaster if you like, in which a massive, globally widespread and geologically rapid loss of species occurred from numerous environments. The “Big five” extinctions of the Phanerozoic (that time since the beginning of the Cambrian period, 541 million years ago) are those in which, in each instance, over half of known species disappeared from the fossil record.

How did they happen? The causes of such events, with a truly global reach, have been a well-known bone of contention within the Earth Sciences community over many decades. The popular media likes to portray such things as Hollywood-style disasters, in which everything gets wiped out in an instant. But in the realms of science, things have changed. The critically important development has been the refinement of radiometric dating, allowing us to age-constrain events down to much narrower windows of time. We can now, in some cases, talk about the start and end of an event in terms of tens of thousands (rather than millions) of years.

Such dating, coupled with the other time-tools of palaeomagnetism and the fossil record, have made it possible to develop a much clearer picture of how mass-extinctions occur. That picture is one of periods of global-scale pollution and environmental stress associated with large perturbations to the carbon cycle, lasting for thousands of years. Such upheavals are related to unusual episodes of volcanic activity with an intensity that is almost impossible to imagine. The geological calling-cards of such events are known as Large Igneous Provinces (LIPs). Bringing environmental and climatic changes at rates similar to the ones we have been creating, they have been repeat-offenders down the geological timeline. This introductory piece examines LIPs in the framework of more familiar volcanic activity: it is the only way to get a handle on their vastness.

For those readers already familiar with LIPs, you may want to skip this and go straight to Part Two, which covers the biggest extinction of them all, at the end of the Permian period, 252 million years ago (Ma). With more than 90% of all species wiped out, it was the most severe biotic crisis in Phanerozoic history. The extinction was global: almost all animals and plants in almost all environmental settings were affected. An idea of the severity can be visualised by considering that the time afterwards was marked by the beginning of a coal gap lasting for ten million years: coal-forming ecosystems simply did not exist for that time. Likewise, Howard Lee has recently considered the relationship between the end-Cretaceous extinction - the one that got the dinosaurs - and LIP volcanism here. But for those who are new to LIPs, it is recommended that you read this post first.



Climate Change: the Terminological Timeline

Posted on 27 August 2014 by John Mason

It is often said that a picture speaks a thousand words. The run of pictures below, it is hoped, will do a little more. They exist as a counterpoint to that laziest of claims - that, a few years ago, "they (the IPCC, Greenpeace, the Committee for Compulsory Implementation of Agenda 21 - take your pick) changed 'global warming' to 'climate change' because (insert pet theory here)".

Skeptical Science has of course published a detailed rebuttal to the talking-point here. But it's important to remind readers that an attempt to make that change in terminology actually occurred - but not by those who are usually accused of the act. Neither was it done for the reasons typically claimed by the opposition: in fact exactly the opposite. In 2002, prior to the mid-terms, the G.W. Bush administration (not exactly famous for its environmental track-record) sought advice on policy communication. It came, from Republican advisor and strategist Frank Luntz, in a long memo (PDF extract here), which included the observation:

"The scientific debate is closing [against us] but not yet closed. There is still a window of opportunity to challenge the science."

Luntz went on to advise:

"The terminology in the upcoming environmental debate needs refinement, starting with “global warming” and ending with “environmentalism.” It’s time for us to start talking about “climate change” instead of global warming and “conservation” instead of preservation.

1.  “Climate change” is less frightening than “global warming.” As one focus group participant noted, climate change “sounds like you’re going from Pittsburgh to Fort Lauderdale.” While global warming has catastrophic connotations attached to it, climate change suggests a more controllable and less emotional challenge.

So there you have it. The only recorded attempt to emphasise "climate change" over "global warming" was to make the latter feel a bit cuddly to prospective Republican voters in 2002. But next time you run into someone trying to suggest otherwise, something that happens multiple times every day, simply link to this page and invite other readers to come and see for themselves. The following images are screengrabs mostly from PDF copies (available via Google Scholar) of peer-reviewed papers going back to the mid 1950s and ending in 1977, when an actual journal called Climatic Change was launched - oh, and don't forget to remind your protagonist of what "CC" stands for in IPCC (founded 1988).

Contrarians may take no notice, but many other readers will be quite capable of making their own minds up, if given checkable evidence. In all but one instance, they can do just that by clicking on a screengrab - they are linked straight to PDF copies of the papers concerned.



IPCC issue official rebuttal to more David Rose/Daily Mail nonsense

Posted on 10 April 2014 by John Mason

David Rose. That name rings a bell, huh? This was the guy who last year  manufactured an IPCC crisis meeting in the UK right-wing tabloid the Daily Mail, where he hangs out and writes pages of nonsense about climate science.  At Skeptical Science, as pointed out in the above link, we have previously pre-bunked and debunked and debunked again his articles on the subject of climate change, but he continues to appear oblivious to legitimate criticism of his work or, indeed, facts.

In his latest offering, Rose manages to turn legitimate criticism of Richard Tol into a "green smear campaign" and his co-author Ben Pile accuses the IPCC of "alarmist spin" concerning certain issues in the Final Draft of the contribution of Working Group II to the Fifth Assessment Report, which was released on March 31st 2014. Accompanying graphics accuse the IPCC of "sexing-up" these topics.


more David Rose nonsense



The Extraordinary UK Winter of 2013-14: a Timeline of Watery Chaos

Posted on 7 March 2014 by John Mason


This is the first post on the exceptionally wet and stormy UK winter of 2013-14. So many severe weather events occurred that they almost seemed continuous a lot of the time. So, to begin with, a timeline is necessary in order for readers elsewhere around the world to appreciate its sheer relentlessness. In a follow-up post, we will take a look at the outbreak of politics that accompanied it, and the scientific debate regarding causes and the possible influence of climate change. But first, a little light entertainment in the form of the run-up to the season in the popular press.

Wild headlines, wild weather (but the complete opposite of the headlines!)

Why is it that when the tabloid media outlets make a prediction, what pans out in reality tends to be the exact opposite? In October 2013, the Daily Express (a UK Conservative-leaning tabloid newspaper) had a front page headline, "Record Snow forecast for November". On November 17th, following a series of pleasantly autumnal days, it followed with, "100 DAYS OF HEAVY SNOW: Britain now facing worst winter in SIXTY YEARS warn forecasters".

It's perhaps useful at this point to explain that the Express has a kind of rota of front page themes that include massively rising house prices, miracle cures for various things, wacky theories about Princess Diana and, well, apocalyptic weather forecasts. Unfortunately, non-meteorologists sometimes take the latter at face value. Having been asked whether the headline was true by a number of elderly people who were anxious about skyrocketing fuel-bills, I got our local paper, the Cambrian News, to publish my advice which was basically, "take no notice", in so many words.

In the piece, I explained that long-range forecasting of weather (as opposed to climate), especially in a part of the world where changeability is the outstanding feature, is simply not possible to any degree of accuracy. The Express has a clever trick up its sleeve: it says that "forecasters warn", bases the gist of its stories on the ramblings of various private weather-forecasters (as opposed to mainstream professional meteorologists) and throws in a few carefully-juxtaposed quotes from the UK Met Office. No wonder readers end up wondering who said what, and many times since I have heard the Met Office blamed for these "forecasts" when in fact it had nothing to do with them. This despite their regularly-issued rebuttals, such as this one: it's an unfortunate fact of life, as Winston Churchill once observed, that a lie will go halfway round the world before the truth has got its pants on.



A rough guide to the components of Earth's Climate System

Posted on 7 October 2013 by John Mason


This is a basic primer on the components of Earth's climate and how and why they are important. It is aimed primarily at people who are relatively new to the subject and who wish to find out more.

Reading a lot of media coverage (and associated comments) with respect to the recently-released IPCC's AR5 Summary for Policymakers, it is apparent that some confusion is being generated over what exactly constitutes Earth's climate. Too frequently, whether by intent or by mistake, the term 'global warming' is only being applied to a subset of a single part of that system, namely the surface temperature record of Earth's atmosphere.

There's a lot more to the climate than that: it is a complex system with a number of key components - the atmosphere, the hydrosphere (oceans, lakes and rivers), the cryosphere (snow and ice), the geosphere (soils and rocks) and the biosphere (living things), all of which play important roles.

Living things act as sources and sinks for carbon. Snow and ice are of paramount importance in controlling the planet's albedo - the amount of sunlight that may be reflected straight back into space. They are in turn sensitive to both air and water temperatures. The oceans act as sinks and sources for both carbon and heat energy and are sensitive to atmospheric conditions overhead, and so on. The following graphic maps the key components out:

The components of Earth's climate system

We will now go on to look at those individual components and how they interact. For ease of reading, let's take them in order of appearance on the graphic, from the top down.

The Cryosphere

The snow and ice on planet Earth consists of five subsets: the ice-caps, polar sea-ice, permafrost, mountain glaciers and seasonal snow-cover. Its biggest part is the gigantic ice-caps that sit atop Greenland and the Antarctic. These have both been losing mass in recent decades due to an accelaration of melting. Such melting makes a direct contribution to sea-level rise. 



Understanding the pre-IPCC Anti-Climate Science Misinformation Blitz

Posted on 26 September 2013 by John Mason

The IPCC AR5 Cometh... and the political carpet-bombing starts in advance! (updated September 27th, 10.20am - see below!)

The basic tenets of science are pretty solid: gravity, plate tectonics, germs that cause disease and so on. The foundations of climate science, such as the role of carbon dioxide as a greenhouse gas, have likewise been well understood for decades. Similarly, in the context of the manufactured political debate that stalks climate science, some things are so equally certain that they will turn up like buses and trains - mostly when expected. A clear example is that whenever a noteworthy climate-related event occurs, contrarian activity ramps up and on occasion goes into hyperdrive. Witness, in the latter context, the weeks leading up to the release of the IPCC Fifth Assessment Report (WG1) Summary for Policymakers, a time in which the background trickle of contrarian activity has become a raging flood.

It started a while back: we noticed an uptick in Astroturfing a few weeks ago: then there was a deluge of grossly-misleading articles in certain mainstream newspapers (the usual suspects) in which an IPCC 'crisis meeting' featured strongly (it was in fact a long-planned routine meeting). Study of the 'discussions' beneath many recent climate change articles in the online versions of our newspapers showed a huge increase in anti-science commentary. It's as though the contrarians have had text-files with a list of climate-myths from which to copy-and-paste as fast as they could. It brought to mind old footage of bomber-planes like B52s in action, engaged in carpet-bombing campaigns, only in this case with randomly-selected anti-climate science myths. In a similar manner to the dubious 'gish-gallop' debating technique, the intention has clearly been to attempt to derail any serious discussion on that rather important topic: the future of Mankind on Planet Earth. 

There are times when a picture is worth a thousand words, and this is one such time, so at this point I'll hand over for a moment to my graphics-savvy colleague JG -  this is the modern face of climate change denialism:

carpet-bombing with anti-climate science myths



How to use short timeframes to distort reality: a guide to cherrypicking

Posted on 25 September 2013 by John Mason

Cherrypicking is the practice, widespread amongst climate change contrarians, of carefully selecting particular points in the noisy short-term climate datasets and using them to show 'trends' that are not representative of the true situation. The huge global surface air temperature spike that accompanied the monster El Nino of 1997-98 is thus chosen as the starting point for the "no warming in 17 15 16 years" that you may read in internet comment-threads below climate stories (the number varies, apparently at random, from commentator to commentator). This year we have seen the Arctic sea-ice melting season once again reported by contrarians as a recovery, although as the graph below, from the National Snow and Ice Data Center, clearly shows, there have been a number of 'recoveries' in previous years too. The long-term trend, as shown by the dotted trendline, is downwards.

Northern Hemisphere ice extent anomalies, August 2013

But that long term trend is exactly what the contrarians, their media allies and echo-chamber denizens do not want the public to read or hear about. Right now, in the run-up to the release of the IPCC Fifth Assessment Report (WG1) Summary for Policymakers, the contrarians are especially busy bombarding everywhere they can with climate change myths. Why not keep tabs on which myths are featuring the most, using our Most Used Climate Myths section on the left of this page? Cherrypicking is a vital tool in their armoury, so let's illustrate it with a working example: how to make Northern Hemisphere summers colder than winters. Sounds like ridiculous fantasy? It is, and is thus in good company with the other climate change myths that the contrarians like to put out.

So just to illustrate how cherrypicking is done, we'll take the upwards temperature trend from winter to summer in the Northern Hemisphere. I've downloaded the monthly HadCET (Central England Temperature) mean dataset, available here, and for 2012 (it should work for any year), I've put the values from January through to July into Excel and plotted a graph:



Arctic sea-ice 'growth', a manufactured IPCC 'crisis' and more: David Rose is at it again

Posted on 10 September 2013 by John Mason

Introduction: like wasps at an August picnic

Manmade greenhouse gases are impeding the return of heat-energy to space and land, ice, water and air are taking in and/or exchanging that heat energy at different rates over time. That is the big picture of the global warming problem: we know there is a growing planetary energy imbalance and it is variously distributing itself as time goes by. Regular Skeptical Science readers might think that quite straightforward, but some others do not share that common sense. Thus the same old, long debunked myths pop up in the mainstream media again and again. Certain key dates seem to encourage this behaviour: the forthcoming IPCC's Fifth Assessment Report being a good example. Like the way a picnic on a sunny afternoon in August tends to attract lots of annoying wasps, major events on the climate change timeline tend to see certain contrarian figures and organisations dialling up the rhetorical output.

This is frustrating yet it has over the years become quite predictable: arguing with some climate change contrarians is similar to attempting debate with a well-trained parrot. Imagine: the parrot has memorised some twenty statements that it can squawk out at random. Thus it will follow up on 'no warming since 1997' with 'in the 1970s they said there'd be an ice-age' and so on. Another piece in the UK-based Daily Mail's Sunday edition of September 8th 2013, written by a figure familiar to Skeptical Science readers, Mail and Vanity Fair journalist David Rose, gives a classic example of such parroting.  There's another in the UK's Daily Telegraph along remarkably similar lines (it could even be the same parrot), and Dana tackled both head-on in a Guardian article on September 9th. Here, we dissect the claims in more detail, free from the restrictions of media word-limits.



East Antarctica Ice-Sheet more vulnerable to melting than we thought: new research

Posted on 31 July 2013 by John Mason

Missing contributor to the 22 +/- 10m Pliocene sea-level rise identified

We know from satellite measurements that the Greenland and West Antarctic ice sheets (GIS and WAIS respectively) are losing mass in response to global warming, and that, in the case of the partly sea-based West Antarctica ice-sheet, basal melting of the ice by warmer ocean-water is likely to be a key mechanism. In the case of the East Antarctica Ice-Sheet (EAIS), the situation has been less clear: thinning of ice shelves and acceleration of glaciers have been described in some areas but it has to date given an impression of relative stability. New research, however, has found that it might not be as resilient to warming as we thought, especially in areas where the bedrock is low-lying.

The research, published in July 2013 in the journal Nature, concerns data collected from marine sediments comprising much (5.3-3.3 million years ago) of the Pliocene Series (spanning 5.3-2.588 million years ago) off the coast of East Antarctica. Its key finding is that during the Pliocene there occurred a series of long, warm intervals during which parts of the East Antarctic Ice-Sheet margin retreated hundreds of kilometres inland. This finding is of importance to our understanding of future global warming and its effects, because the climate during the Pliocene was similar to that predicted for the latter part of the current century and atmospheric greenhouse gas concentrations were similar to those of the present day.

Modelling has already suggested that low-lying areas of the EAIS are candidate zones for Pliocene melt. In fact, some extra ice-melt is likely required to explain global sea-level changes during the Pliocene. That there were periods of significant sea-level rise is understood, but estimates of the amount vary, leading to the figure of 22 +/- 10 metres. What seems likely, however, is that sea-level rise due to the collapse of the GIS and WAIS would, at around 12m, appear to be insufficient to accomplish such an inundation. That these ice-sheets periodically collapsed during Pliocene times has been covered this year at Skeptical Science, here.



Understanding the long-term carbon-cycle: weathering of rocks - a vitally important carbon-sink

Posted on 2 July 2013 by John Mason

The long-term carbon-cycle

 above: the processes of the long-term carbon-cycle that this post explores. Graphic: jg.

This post delves into the long-term carbon cycle that involves the interactions of the atmosphere with rocks and oceans over many millions of years. Because of its length, I've broken it up into bookmarked sections for easy reference: to come back here click on 'back to contents' in each instance.


Introduction: what is weathering?

Carbon dioxide and rock weathering: the chemistry

Limitations to the precipitation of calcium carbonate: the Carbonate Compensation Depth

The significance of weathering as a carbon-sink

Deep weathering of rocks: an illustrated example from Mid-Wales, UK

How breaking up minerals affects their weathering-rate: mountain-building as an accelerant

Picking up signals of major weathering episodes in the geological record

Introduction: what is weathering?

Weathering is a familiar process to us all. It involves the chemical reactions between chemical compounds in the atmosphere and chemical compounds on the planet's surface. When your car's exhaust pipe falls apart noisily, it is because the steel from which it was constructed has, over several years, reacted with oxygen and rainwater to form rust. It has weathered. But that's a relatively fast example involving a relatively unstable compound. The compounds making up the vast majority of Earth's land surface - the minerals that make up rocks - are, by and large, very slow to react. As a consequence, large-scale weathering is a process that takes place on a timescale of millions of years, over which periods it constitutes a critically important carbon-sink.



UK Secretary of State for the Environment reveals his depth of knowledge of climate change (not!)

Posted on 12 June 2013 by John Mason

An extraordinary - and worrying - insight into the mind of Owen Paterson, Secretary of State for the Environment here in the UK, was provided during a June 7th edition of the political Q&A programme Any Questions, available on BBC Radio 4 here. The programme is broadcast from a different venue every week and consists of chairman Jonathan Dimbleby and a panel of four politicians and commentators plus a studio audience who ask a selection of topical questions. This edition was from my home town of Machynlleth in Mid Wales and more specifically from the Centre for Alternative Technology, which has been promoting renewable energy and other sustainability issues since the 1970s.

This week's panel was made up of Peter Hain, Labour MP for Neath, Leanne Wood, leader of Plaid Cymru, Owen Paterson, UK Secretary of State for the Environment and James Delingpole, blogger and well-known inhabitant of an alternate universe when it comes to climate science.

A question from audience member Sally Carr (at 29 minutes 22 secs into the broadcast) caught my attention:

"Are those concerned about climate change talking anti-scientific green ideological nonsense?"

This is of course a Delingpole quote (Daily Telegraph, June 4th 2013) turned back at him, as Dimbleby himself observed. Delingpole was on first and gave a typical performance stuffed to the gills with strawman arguments and many 'usual suspect' talking points that we have debunked beyond death here at Skeptical Science - "no warming since 1997", of course, plus a few throwaway comments about yoghourt-weavers and eco-loons, accompanied by much spirited heckling. The only thing missing was a "POLAR BEARS ARE NOT EXTINCT" arm-waving exercise. All typical Delingpole and exactly what anyone would expect. The following graphic is sufficient to address his entire attitude in general:



Video: Lake El'gygytgyn, Pleistocene super-Interglacials and Arctic warmth

Posted on 1 June 2013 by John Mason

Here is a must-see 2012 presentation by Julie Brigham-Grette of the University of Massachusetts Amherst, covering the research her team has been doing into Lake El'gygytgyn (pronouned El-Guh-Git-Kin), a water-filled meteor crater in Arctic Russia that came into being after the impact of a ~1km diameter space-rock, 3.6 million years ago.

This is incredibly important work because:

  • The Lake El'gygytgyn region was not glaciated during any of the ice ages. As a consequence, the >300m accumulated sequence of lake sediments represents a continuous, undisturbed sedimentary record going all the way back from the present to the aftermath of the impact.
  • The team succeeded in 2009 in extracting cores spanning this entire 3.6 million year period.
  • The oldest continuous ice core records to date extend 123,000 years in Greenland and 800,000 years in Antarctica: the Lake El'gygytgyn cores go way back beyond those times and provide an unprecedented view of the past climate of the Arctic.
  • Results show that during the Pleistocene (2.588 million - 11.7 thousand years ago), there were a number of super-interglacials - like the present period but much wetter and several degrees warmer in the Arctic, during which the Greenland and West Antarctic ice-sheets didn't just melt a bit. They disappeared.

Skeptical Science recently covered the new 2013 paper by the same team, describing the Arctic climate in the Lake El'gygytgyn region during the Pliocene, when boreal forests extended well up into the Arctic and summer temperatures were 8oC warmer than they are at present:

The last time carbon dioxide concentrations were around 400ppm: a snapshot from Arctic Siberia

The data coming from Lake El'gygytgyn strongly suggest that the Arctic climate is highly sensitive to small changes in forcing, warming much faster than the rest of the world in the phenomenon known as Arctic Amplification. In recent years, Arctic Amplification has emerged as a strong modern-day climate signal. To cite but one example, the sea-ice response has been of far greater magnitude than model-based forecasts projected. Now, the past is giving a similar narrative, and understanding the climate of the past gives us our best chance of understanding the climate of the future.

Readers of Skeptical Science can expect to encounter more news from Lake El'gygytgyn in due course. In the meantime, why not watch the 24-minute video to see for yourself?




A Rough Guide to the Jet Stream: what it is, how it works and how it is responding to enhanced Arctic warming

Posted on 22 May 2013 by John Mason

Barely a week goes by these days in the Northern Hemisphere without the jet stream being mentioned in the news, but rarely do such news items explain in detail what it is and why it is important. As a severe weather photographer this past 10+ years, an activity which requires successful DIY forecasting, I've had to develop an appreciation into what makes it tick. This post, then, is a start-from-scratch primer based on that knowledge plus some valuable assistance from academia into where the current research is heading. Because of its length and breadth of coverage, I've broken it up into bookmarked sections for easy reference: to come back here click on 'back to contents' in each instance.


Earth's Troposphere - an introduction

Weather systems aloft - the Polar Front and the jet stream

Waves on the jet stream - upper ridges and troughs

Positive vorticity - a driver of severe weather - and the jet stream

Wind-shear - a driver of severe weather - and the jet stream

Jetstreak development along the jet stream - a driver of severe weather

Northern Hemisphere atmospheric circulation patterns: the Arctic and North Atlantic Oscillations

Climate change and the future: how will the jet steam and pressure-patterns respond?


Earth's Troposphere - an introduction

back to Contents

We live at the bottom of a soup of gases, constantly moving in all directions - our atmosphere. Virtually all of our tangible weather goes on in its lowest major division, the Troposphere. This division varies in average thickness from about 9000m over the poles to 17000m over the tropics - in other words, it's thinnest in cold areas and thickest in hot areas, because hot air is more expansive than cold air. Likewise it fluctuates in thickness on a seasonal basis according to whether it's warmer or colder. Above it lies the Stratosphere, while below it lies the surface of the Earth.



The last time carbon dioxide concentrations were around 400ppm: a snapshot from Arctic Siberia

Posted on 14 May 2013 by John Mason


During the late Pliocene and early Pleistocene Series of the Cenozoic Era, 3.6 to 2.2 Ma (million years ago), the Arctic was much warmer than it is at the present day (with summer temperatures from 3.6-3.4 Ma some 8oC warmer than today). That is a key finding of research into a lake-sediment core obtained in Eastern Siberia, which is of exceptional importance because it has provided the longest continuous late Cenozoic land-based sedimentary record thus far. The sedimentary sequence dates from recent times back to 3.6 Ma when the lake was formed by a large extraterrestrial impact. During the warm period, atmospheric carbon dioxide concentrations were close to those of today, at around 400 parts per million, indicative of a strong climate sensitivity signal in the Arctic, which has again warmed very rapidly in recent decades. The lake sediment record has thus provided us with a snapshot of how the Arctic may look in the near future.


Geologists divide geological time into Eons (the longest divisions), Eras, Systems and Series. The Pliocene (5.333-2.588 Ma) is the final Series of the Neogene System and the Pleistocene (2.588 Ma-11,700 years ago) is the first Series of the Quaternary System, both being part of the Cenozoic Era, the latest Era of the Phanerozoic Eon.

Just to get that into context, here is all of geological time plotted against the human 12-month calendar year, so that geological time starts on the first second of New Years' Day and the present is the last second of New Years' Eve. On such a scale, the whole Cenozoic Era equates to a tiny bit of late December!

All of Geological time plotted against the human year



Death in Jurassic Park: global warming and ocean anoxia

Posted on 15 March 2013 by John Mason

New research links greenhouse gas-related global warming to severe environmental degradation and a mass-extinction during the Lower Jurassic Period, around 183 million years ago.


As any aquarium-keeper will know, a critical factor in the wellbeing of their collection involves the amount of oxygen in the water. Marine animals, from lowly worms through to large sharks, all have one thing in common in that they extract dissolved oxygen from seawater for the purpose of respiration. Take that dissolved oxygen to a critically low level - hypoxia - and they will struggle to survive - just as most climbers would end up in a very groggy state if they attempted to climb to the summit of Everest without bottled oxygen, relying only upon the increasingly hypoxic air that one encounters with increasing altitude. Take that dissolved oxygen down to zero - anoxia - and pretty much everything is dead, period.

Marine hypoxic and anoxic events are well-known from the geological record and have been in some cases so widespread as to lead to mass-extinctions. This piece explores some recent research that describes one such event during the Toarcian stage of the Lower Jurassic period, some 183-174 million years ago (fig.1).

Geological timechart and details of the Jurassic Period

Fig. 1: L: Geological time, plotted against the 12-month human calendar, so that Earth begins existence on New Years' Day and now is New Years' Eve, just before midnight. R: Details of the Jurassic Period and the Stages into which it is divided by geologists. This post concerns events that took place in the latest stage of the Lower Jurassic. Mya = millions of years ago.

The Jurassic Period in general had a warm global climate, but during the Toarcian stage there was a period of additional global warming in which temperatures are estimated to have increased by 2–3.5oC in subtropical areas and 6–8oC at higher latitudes. The fact that such values are similar to projections for the end of this century under a business as usual scenario will not be missed by readers. The time in question is also marked by a 'negative excursion' in the carbon isotope record, meaning a spike occurred in atmospheric carbon concentrations - a feature in common with other major warming events in the geological record, such as the Palaeocene-Eocene Thermal Maximum, 55 million years ago. However, before looking at the event in question, let's take a look at oxygen in seawater and what makes it tick.



The Great Disconnect: the human disease of which climate change is but one symptom

Posted on 7 February 2013 by John Mason

'I grieved to think how brief the dream of the human intellect had been. It had committed suicide. It had set itself steadfastly towards comfort and ease, a balanced society with security and permanency as its watchword, it had attained its hopes - to come  to this at last...'

'...It is a law of nature we overlook, that intellectual versatility is the compensation for change, danger, and trouble. An animal perfectly in harmony with its environment is a perfect mechanism. Nature never appeals to intelligence until habit and instinct are useless. There is no intelligence where there is no change and no need of change. Only those animals partake of intelligence that have to meet a huge variety of needs and dangers.' 

from The Time Machine by H.G. Wells (1895)

 Connectivity. We utterly rely on it. Without connectivity, our civilisation ceases to exist. That's a big statement to make, but I will argue below how, over the past fifty years, many of us have lost the full understanding of its importance, or in many cases have not developed such an understanding. In a destabilising climate, that  detachment becomes all the more problematic.

Some connections we still manage to make with ease. We know that if there is a power-cut, things that run on mains electricity will, in the absence of a generator, not work. We know that if there is a heavy snowstorm then the roads will be paralysed. We fully understand that, if the systems we have devised go down, then disruption to our day-to-day lives will ensue until the problems are fixed, the power reconnected and the snow thaws. We see and feel the connectivity of these systems and plan for them accordingly - candles in the cupboard, a shovel in the car boot during the winter months, and so on.

 Like a human tide....

above: like a human tide... lights on the highway



Met Office decadal forecasting explained: the reality

Posted on 11 January 2013 by John Mason

"Decadal forecasts provide essential information about ocean ‘weather’ and how it will evolve in the next few years in the context of a globally warming world, but they do not tell us anything about  long-term climate sensitivity  (i.e. how much the planet will warm for a specified increase in radiative forcing related to greenhouse gases)."

UK Met Office, January 2013

In 2012, the Hadley Centre (the climatology section of the UK Met Office) introduced its latest multi-year forecast model, HadGEM3, into the decadal forecasting system, replacing the earlier HadCM3 (figs. 2 and 3, below), developed in the earliest years of the 21st Century. HadGEM3 represents the product of many years of detailed research and involves a better understanding of the many variables that work together to bring us the climate we experience. Running the model involves a phenomenal amount of number-crunching, to such an extent that it is only run out to T+ 5 years — to run it out further would hog too many computing resources. It is the first of these five-year runs that has attracted so much media attention of late. But what kind of forecast is it, exactly? Here lies the source of much of the misunderstanding. Having spoken at length to the Met Office about this subject on January 10th, I'll try to explain.



Food Security: the first big hit from Climate Change will be to our pockets

Posted on 26 December 2012 by John Mason

"While the global community has committed itself to holding warming below 2°C to prevent “dangerous” climate change, the sum total of current policies—in place and pledged—will very likely lead to  warming far in excess of this level. Indeed, present emission trends put the world plausibly on a path toward 4°C warming within this century."

Turn down the Heat - why a 4oC warmer world must be avoided

World Bank, 2012

Met Office - UK rainfall, June 2012I've been growing a lot of my own food this past few years and amongst the varied challenges I've had to work around, the dismal summer of 2012 here in Wales has been the greatest of all. A cold and often overcast spring was followed by an exceptionally wet summer - the Met Office graphic for June (R) spells that out in no uncertain terms - and the few brief flickers of warmth that were felt early in the autumn came too late: the wind and rain soon set in again.

How did that affect the crops? Well, firstly, despite all sorts of control measures, including dead-of-night visits armed with a torch and bucket, the slugs had a field-day, chomping their way through anything they fancied. Slugs are always a nuisance to veg-growers, but the conditions this summer were just about perfectly in their favour. But there was more to it than that: the cold spring meant that the soil was slow to warm; bees and hoverflies, both vitally important to any grower, were both late to appear and in short supply and the severely reduced sunshine further compounded things. In short, it was a bit of a disaster!



Newsflash: A 4°C warmer world can, and must be, avoided - World Bank

Posted on 21 November 2012 by John Mason

Regular readers of Skeptical Science will be well aware of the growing signs of destabilisation in the global climate. Coming hard on the heels of a plethora of other warnings, the World Bank have now released a must-read report, dated November 18th 2012.  It runs to 106 pages, which we'll read and digest before a more detailed analysis is posted (soon!): in the meanwhile, here is an excerpt from the above link.

Key Points:

  • New World Bank-commissioned report warns the world is on track to a “4°C world” marked by extreme heat-waves and life-threatening sea level rise.
  • Adverse effects of global warming are “tilted against many of the world's poorest regions” and likely to undermine development efforts and goals.
  • Bank eyes increased support for adaptation, mitigation, inclusive green growth and climate-smart development.

Turn Down The Heat - World Bank on Climate Change



Record Arctic Sea-ice minimum 2012 declared - it's the Silly Season!

Posted on 22 September 2012 by John Mason

The truth is incontrovertible. Panic may resent it, ignorance may deride it, malice may distort it, but there it is. Winston Churchill, 1916.

Late summer has long been known in media circles as the Silly Season, when any old story, embellished a bit here and a bit there, is trundled out to fill column space normally occupied by the graver matters of politics and business.

In the world of climate science, late summer is of course rather more important, marking the peak of the annual sea-ice melting season of the Northern Hemisphere, and this year has been extraordinary, with the canary in the coal mine tweeting louder than ever that something is seriously amiss with the climate.

With Arctic sea-ice having reached a record low extent, area and volume, several weeks ahead of the usual end-of-melt date, the Blogosphere has been ablaze with lengthy discussions of this event and its potential and worrisome ramifications. There have also been mass-outbreaks of denial accompanied by varying degrees of silliness, as one might expect when faced with an event like a record Arctic melt-out. Many commentators could see the meltdown approaching, both in the Arctic and around parts of the Blogosphere, with Gareth Renowden over at Hot Topic speculating in early August as follows:



Unpicking a Gish-Gallop: former Greenpeace figure Patrick Moore on climate change

Posted on 25 August 2012 by John Mason

Who recently said this?

"If we stopped using fossil fuel today, or by 2020 as Al Gore proposes, at least half the human population would perish and there wouldn't be a tree left on the planet with[in] a year, as people struggled to find enough energy to stay alive."

And some people call us 'alarmists'!!

The excerpt comes from a recent piece in the Conservative-leaning Washington Times, to which links are being circulated in the certain quarters of the Blogosphere. The source? Patrick Moore - not the famous TV astronomer, but a former early member of Greenpeace, with which he was involved at various levels between 1971 and 1986, before leaving the organisation to take up salmon-farming in British Columbia and then going on to become involved in PR consultancy for various industries. He managed to exasperate his former organisation sufficiently to have a press release dedicated to him in 2008, and two years later he came under journalist George Monbiot's beady eye in this article, published in The Guardian. Now he's back, with an interview entitled 'Patrick Moore on the facts and fiction of climate change'. Reading down the page, beyond the paragraph from which the above statement was taken, one is treated to a classic example of a well-known debating tactic, the so-called Gish-Gallop. As this is a frequently used ploy by fake-sceptics, it's worth using this example to explore what a Gish-Gallop is and how it works.



‘It’s not looking good for corn’ - new video from Peter Sinclair

Posted on 6 August 2012 by John Mason

Here's a new video from Peter Sinclair, the latest in his excellent 'This is not cool' series, reposted from the Yale Forum. I've long admired Peter's incisive techniques when it comes to communicating the reality of climate change and the dangers it poses. In this case, with severe problems in the arable sector of the USA due to the prolonged heat and drought that has been experienced, climate change is going to hit a lot of ordinary people in the pocket as food prices rise in response. Perhaps someone ought to ask James Inhofe, Republican Senator for drought-stricken Oklahoma, what he plans to do about that. It's supposed to be his job, after all. But don't hold your breath. In a March 2009 speech, he declared:

"I will now report to you about the skeptical Heartland Institute’s International Conference on Climate Change in New York City this week. As the most outspoken critic of man-made global warming alarmism in the United States Senate, I am pleased to see the world’s largest-ever gathering of global warming skeptics assemble in New York City to confront the issue, “Global warming: Was it ever really a crisis?”

Meanwhile, back home in Oklahoma, triple-digit temperatures continue and the wildfires burn on. Over to Peter:



The Mid-Wales floods of June 2012: a taste of things to come?

Posted on 20 July 2012 by John Mason

Sitting on the western side of a landmass that already juts out prominently into the Atlantic, facing into the prevailing moist sou-westerlies and having lots of high ground just set back from the coast, Wales has a deserved reputation for having a wet climate. It is generally a very green country. Not all the time, it must be said: the summer of 2006 was marked by a drought so severe that farmers ended up having to cut sections of fence to allow stock to access what springs were still flowing, and it was the year in which a farmer friend was one of many who decided to have a borehole drilled as a new and more reliable water supply.

I've lived here in Mid-Wales for over 30 years now and having a strong interest in meteorology I've investigated all sorts of severe weather, from the Great Blizzard of 1982 to the EF-2  tornado that tore a path of destruction through a neighbouring village late in 2006. I've seen the aftermath of flash floods following severe thunderstorms and have even chased the occasional supercell. But I don't think any of these events have been so shocking as the Mid-Wales floods of June 8-9 2012.

Map showing the area affected by the 8-9th June 2012 floods

above: map of the area of Wales affected by the floods of June 8-9, 2012. Green triangles are summits, the highest of which is Plynlimon (752m). Large red circles are towns; small ones are villages. Roads are in red; rivers in blue. Graphic: author



Two Centuries of Climate Science: part three - Manabe to the present day, 1966-2012

Posted on 11 May 2012 by John Mason

The fact that carbon dioxide is a 'greenhouse gas' - a gas that prevents a certain amount of heat radiation escaping back to space and thus maintains a generally warm climate on Earth, goes back to an idea that was first conceived, though not specifically with respect to CO2, nearly 200 years ago. The three-part tale of how this important physical property, its role in the geological past and understanding how it may affect our future, covers about two centuries of enquiry, discovery, innovation and problem-solving.

This post is Part Three of this series, which also includes Part One and Part Two.

Climate Science Timeline, 1960-today

graphic: jg



Two Centuries of Climate Science: part two - Hulburt to Keeling, 1931- 1965

Posted on 2 May 2012 by John Mason

The fact that carbon dioxide is a 'greenhouse gas' - a gas that prevents a certain amount of heat radiation escaping back to space and thus maintains a generally warm climate on Earth, goes back to an idea that was first conceived, though not specifically with respect to CO2, nearly 200 years ago. The three-part tale of how this important physical property, its role in the geological past and understanding how it may affect our future, covers about two centuries of enquiry, discovery, innovation and problem-solving.

This is Part Two of this series, which also includes Part One and Part Three.

 Atmospheric carbon dioxide levels from the late 1950s onwards

above: atmospheric carbon dioxide levels from the late 1950s onwards. The red wiggles mark out seasonal variations in uptake by plants.

We resume this narrative in 1931, when American physicist E.O Hulburt ran calculations to determine the effect of doubling carbon dioxide once again, and, including the added burden of water vapour, he came up with a figure of around 4°C of warming. He also rebutted Ångström's work and determined that, regardless of convective processes, it was the escape of infra-red radiation to Space (or the hinderance thereof) that was of key importance. The resultant paper appeared in a the journal Physical Review, which tended not to be read by earth and atmospheric scientists and was as a consequence missed by many of them. In any case, it was generally thought that Earth's climate system maintained itself in some natural kind of balance. In retrospect, given the dramatic climate changes that had led to the ice-ages, this was a curious stance to take.

Seven years later, English engineer Guy Callendar, something of an outsider (a steam-engine specialist but with a very keen interest in meteorology), revived the idea, having discovered evidence of a warming temperature trend in the early twentieth century from compilations of temperature records. At long last, the actual levels of carbon dioxide in the atmosphere were revisited: Callendar found they had increased by some 10%, which he suggested may have caused the warming, and he went on to add that over the coming centuries there could be a climate shift to a permanently warmer state.



Two Centuries of Climate Science: part one - Fourier to Arrhenius, 1820-1930

Posted on 26 April 2012 by John Mason

The fact that carbon dioxide is a 'greenhouse gas' - a gas that prevents a certain amount of heat radiation escaping back to space and thus maintains a generally warm climate on Earth, goes back to an idea that was first conceived, though not specifically with respect to CO2, nearly 200 years ago. The three-part tale of how this important physical property, its role in the geological past and understanding how it may affect our future, covers about two centuries of enquiry, discovery, innovation and problem-solving.

This is Part One of this series, which also includes Part Two and Part Three.

To pick up the scientific trail of what is today known as the Greenhouse Effect, we need to travel back in time to France in the 1820s. Napoleon, defeated at the Battle of Waterloo just a few years previously, had just died, but somebody who had at one time undertaken significant engineering and academic projects for the late Emperor was now busily engaged on his investigations of the physical world, with a specific interest in the behaviour of heat. This was Jean Baptiste Joseph Fourier (1768–1830).

Fourier had calculated that a planetary object the size of Earth should, quite simply, not be as warm as it is at its distance from the Sun. Therefore, he reasoned, there must be something else apart from incoming solar radiation, some other factor that keeps the planet warmer. One suggestion he came up with was that the energy coming in from the sun in the form of visible and ultra-violet light (known back then as "luminous heat") was easily able to pass through Earth's atmosphere and heat up the planet's surface, but that the "non-luminous heat" (now known as infra-red radiation) then emitted by the Earth's surface could not make it back in the opposite direction quite so readily. The warmed air must, he reasoned, act as some kind of insulating blanket. That was about as far as he got with the idea back then, as the detailed measurements required to explore this hypothesis were not available, given the technology of the day.

Fourier, Tyndall & Arrhenius - the grandfathers of climate science
above: the Grandfathers of Climate Science



Submerged Forests off the coast of Wales: a Climate Change Snapshot

Posted on 7 April 2012 by John Mason

Sea-level rise over the past 10,000 years is recorded in Cardigan Bay, off the western seaboard of Wales, UK. Peat-beds complete with the remains of trees are today exposed over low tide along several of the Bay's beaches. Incredibly, a new exposure of peat has recently yielded human footprints, made some 3000 years or more ago by the people who witnessed the final stages of the drowning of the land.

The deglaciation that followed the Last Glacial Maximum, twenty thousand years ago, was accompanied by a global sea-level rise that averaged out at some 120 metres. Around the British Isles, there are many areas covered by shallow seas, 10-20 metres in depth, and Cardigan Bay, off the west-facing coast of Wales, is one of them. Sailing due west from the local coastal ports such as Aberystwyth and Aberdyfi, it is a good ten nautical miles before the 20m submarine contour is reached. The sea-bed is a sandy table-land, divided by several great ridges of gravel and boulders - the Sarnau (Welsh for Roads) - that mark the lateral moraines of the valley-glaciers that flowed out westward to join the Irish Sea Ice-Sheet.

View across Cardigan Bay with one of the Sarnau in the foreground

above: view across Cardigan Bay to the Snowdonia mountains, with one of the Sarnau, Sarn Cynfelyn, in the foreground. It extends out beneath the sea as a steep-sided reef for over six nautical miles. Photo: author.



Catching up with the Younger Dryas: do mass-extinctions always need impacts?

Posted on 24 March 2012 by John Mason

Perhaps the most curious aspect of Earth's emergence from the last glacial maximum, a process that began just under 20,000 calendar years ago, was the Younger Dryas, (named after the pollen-record of the beautiful plant that is now grown in many rock-gardens - my Grandfather grew it and I did in my time): a period beginning 12,900 years before present and lasting over 1,000 years during which the planet, and especially the northern hemisphere, cooled rather abruptly and, at high latitudes, glacial re-advance commenced.  Ending even more abruptly, perhaps in as little as a few decades, it marked the final cold snap before the advent of the more temperate conditions of the Holocene Period. So: what caused it?

The last twenty thousand years

above: the Younger Dryas in the context of the past twenty thousand years. The later (post-Neolithic) periods refer primarily to Western Europe.



Climate Deniers Are Giving Us Skeptics a Bad Name - Fred Singer

Posted on 17 March 2012 by John Mason

Somebody recently drew our attention to a provocatively-titled piece by Fred Singer on the website of the Independent Institute, another of those many political think-tanks over in the USA. We had a look at the piece and it turns out that it is another strange example of someone well-known over many years for their contrarian views on climate change (among other things) attempting to claim some kind of 'middle ground'. In short, as you will see below, he is saying, "most deniers [his term, which he uses a lot] are wrong, most climate scientists are wrong but I'm right".

It's not the first time we've seen someone trying to re-jig the debate, with a number of leading political anti-science activists now saying that they accept that the greenhouse effect exists and that temperatures are increased by Mankind's industrial emissions of carbon dioxide and other gases (but only by a teeny-weeny little bit). In doing so, they are putting ground between themselves and the rank-and-file who daily appear on comment threads to insist that the greenhouse effect doesn't exist, is a hoax and blah blah blah. It's as if they have realised that there is no longer any mileage in promoting that particular bunch of myths to policymakers and public alike, so that instead they are going for climate sensitivity as an alternative target. "Calling all think-tanks. Calling all think-tanks. Go to Plan B, repeat, go to Plan B."

Independent Institute

OK then, let's take a closer look. All of Singer's text is in italics.

Singer begins by drawing up his view of where the 'balance' exists in the climate debate:



Declining Arctic sea-ice and record U.S. and European snowfalls: are they linked?

Posted on 14 March 2012 by John Mason

It is often said of the Arctic that, when it comes to climate change, this region of Earth is the proverbial 'Canary in the Coalmine' - that is, if anywhere is going to alert us that something's up, it's up there in the far north. So we have seen sea-ice coverage diminishing dramatically and sea-ice volume falling off a cliff. Land-ice too is on the retreat: a mineral exploration company that has returned to the Black Angel mine in western Greenland, last worked from 1973-1990, have found a new orebody exposed at surface, where "the existence of mineralisation at this location was known, but previously it was covered by 60m of ice." Just recently Skeptical Science reviewed the science and ran an interview with one of the lead scientists in a team investigating extensive outgassing of methane from the sea-bed of the East Siberian Arctic Shelf, possibly linked to the degradation of undersea permafrost. There's a lot going on up there, to which we can add the accumulating evidence that, paradoxically, reductions in sea-ice cover may be driving changes in atmospheric circulation patterns that have been behind the severely cold plunges and record-breaking snowfalls seen over the continents at more temperate latitudes in recent winters.

Living where I do, not far from the west coast of Wales, in that part of NW Europe that sticks furthest out into the Atlantic Ocean, cold winters are in general uncommon. The months of December, January and February are often dominated by zonal conditions in which Atlantic depressions are bowled at us one after another by a strong westerly jetstream. On occasion, high pressure builds on a N-S axis in the mid-Atlantic, allowing a northerly flow bringing snow-showers, but typically such events are over within a few days. In both 2009-10 and 2010-11, things were radically different. I well recall Christmas morning in 2010: it was symbolic of the whole affair in a month that had seen almost continuous snow and ice, and just when I thought it couldn't get any worse, I came downstairs to be greeted by a centimetre of solid ice on the tiled bathroom floor. I had left the taps a-dripping overnight, but what I hadn't accounted for was that ice built up outside, sealing the outflow-pipe so that back-pressure had forced an 'o'-ring joint apart where the pipe went through the wall, allowing the water to make its way across the floor until it got so cold that it, too, froze. The taps by that point had both stopped dripping as well. Not the most auspicious start to a day.

Ice-floes on the Dyfi Estuary, December 2010

above: ice-floes along the Dyfi Estuary, Mid-Wales, December 2010. Photo: Author



Arctic methane outgassing on the E Siberian Shelf part 2 - an interview with Dr Natalia Shakhova

Posted on 19 January 2012 by John Mason

In December 2011, following a fresh flurry of sometimes conflicting media reports about methane outgassing on the East Siberia Arctic Shelf (ESAS), we decided to go and talk to the people doing the work on the ground. We are pleased to report that Dr Natalia Shakhova (NS below) of the University of Alaska in Fairbanks agreed to be interviewed by the author, on behalf of Skeptical Science, via email. Here are the responses, verbatim, to our questions.



Above: Bathymetric map (source - NOAA) of the Arctic with key features noted and the subject area highlighted in red.


SkS: In your JGR paper from 2010 you state that methane hydrate in Siberia can occur at depths as shallow as 20 m. Have any such remarkably shallow methane hydrate deposits on the ESAS been directly observed/sampled and if so, how could methane hydrate have formed at such depths?

NS: Yes, such shallow hydrates were sampled in Siberia. They form as a result of the so-called “self-preservation phenomenon” and they are termed “metastable”. This phenomenon has been intensively studied by Russian geologists starting in the late 1980s.



Arctic methane outgassing on the E Siberian Shelf part 1 - the background

Posted on 15 January 2012 by John Mason

Reports of extensive areas of methane - a powerful greenhouse gas - bubbling up through the shallow waters of the East Siberian Arctic Shelf (ESAS) have been doing the rounds in the media recently, with some articles taking the apocalyptic approach and others the opposite. So what IS going on in the far North? In this two-part post we will first examine the data available to date and then in part two we go on to discuss the findings of 2011 with the research team who have been doing the work on the ground.


To understand the goings-on up at the ESAS in context, we need to go back to the time of the last glacial maximum, some 20,000 years ago. Although the climate was cold, much of Siberia remained unglaciated for the simple reason that the climate was also extremely dry: the main area of glaciation was in the Verkhoyansk Range in the east, which rises to nearly 2500m. The low-lying plains of central Siberia saw the development of permafrost - defined as soil that remains at below freezing point for two or more years. The prolonged cold of the last glacial period saw permafrost develop to great depths - over 1000m in places.  Extensive areas of this old permafrost, albeit thinner than at the last glacial maximum, exist at the present day. On land, permafrost occurs several metres below surface, and is overlain by the so-called active layer, soil which seasonally thaws out and in which the Siberian flora grows.

Map of the Arctic showing the East Siberian Shelf

Above: Bathymetric map (source - NOAA) of the Arctic with key features noted and the subject area highlighted in red.



The End of the Hothouse

Posted on 16 December 2011 by John Mason

A new study links major atmospheric CO2 drop to the onset of Antarctic glaciation, 33.7 million years ago

Forty million years ago, Antarctica had a pleasantly mild climate, its mountains and shores flanked by swathes of woodland in which a diverse mammalian fauna flourished. Today, it is one of the most inhospitable places on Earth. Throughout this time, the continent has remained in pretty much the same place, straddling the South Pole. It follows that a drastic climatic change must have occurred, but how?

That has been the subject of much research over the years and a good picture has gradually emerged. Now, a new paper in the journal Science has clarified the role of rapidly-declining atmospheric carbon dioxide levels in the temperature-plunge that saw the rapid onset of Antarctic glaciation, 33.7 million years ago. The fall in CO2 concentration was from 1000-1200 ppm down to 600-700ppm, at which point it was cool enough to allow glaciers to start to form. That our current emissions path takes us beyond the latter levels by 2100 means that we are heading straight towards a planet that may no longer sustain polar ice-caps, resulting in a steady melt and relentless sea-level rise that will duly threaten every coastal city in the world. We'll see what the research found out in a moment, but first let's take a quick look at the Cenozoic Era, the geological timespan during which the glaciation of Antarctica began.



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