It’s common knowledge that there used to be an Ice Age in this country. Something which is never clear to me is whether people generally realise that this planet has recently, i.e. in the past million years or so, undergone five ice ages, and it’s debated whether anthropogenic climate change will be sufficient to prevent the next one. As I mentioned the other day, up until the 1980s it was considered a toss-up whether the near future would involve global cooling or warming, although looking at the graph of recent global temperatures in 1977, it seemed close to inevitable that it would warm. But there have been people here for hundreds of millennia, back to the Hoxnian about four hundred millennia ago, so I will start with that, work down to the present and then go way up and repeat the process on a grander timescale.
As far as I know, and in fact I suspect I’m wrong, the earliest human remains found in what are currently these isles are the so-called “Swanscombe Man”, a Neanderthal or pre-Neanderthal woman dating from about four hundred millennia BP (before present – in fact before 1950 CE). She was found in a Swanscombe gravel pit, near Dartford in today’s Kent. The Hoxnian Stage was an interglacial lasting from 424 to 374 millennia BP, when it was slightly warmer than today on average. At the time, there were dense forests here, making it difficult for people to penetrate much of the country and they mainly stayed in river valleys, such as the Thames, then a tributary of the Rhine, where the Swanscombe remains were found. Other species sharing that environment included the straight-tusked elephant, hippos and rhinos. This is one of the startling things about British fauna, and in fact fauna in general, up until the start of the last Ice Age: it was actually quite Afrikan. Distinctive European fauna during interglacials didn’t arise until this one, referred to as the Holocene. In fact humans could be seen as an example of that, since we are originally Afrikan.
I grew up calling the Ice Ages of the Pleistocene Donau, Günz, Mindel, Rịẞ and Würm, which are apparently the wrong names for Northern Europe, where they’re called the Hamburger, Elder, Elster, Saale and Weichsel. One of the annoying things about ice ages is that they’re called different things in different parts of the world, which doesn’t generally happen with other geological periods although one of the Cenozoic epochs, can’t remember which, is said to continue in some parts of the world after it had finished in others. Possibly the Oligocene. In the case of ice ages this is to some extent justified, because as far as the Arctic regions are concerned we’ve been in one long ice age since the start of the Pleistocene. Britain, and in particular Scotland, is the northernmost land not actually considered Arctic, so it isn’t surprising that the ice ages operated somewhat differently here than they did further south. The names I mentioned at the beginning of this paragraph are also the names of Alpine rivers, because the Alps were obviously more strongly affected than lower-lying parts of the European peninsula.
When the Ice Age I’m apparently supposed to call the Saale started around 374 millennia BP, glaciers completely covered what would become this archipelago, and of course Doggerland in the German Ocean/North Sea was still completely above sea level, so at this point these isles were not islands at all but a sub-peninsula of Europe. Fauna included lemmings, mammoths, woolly rhinos and musk oxen, but there would’ve been an intermediate cooling period during which horses would have arrived because the forests were thinning out. This came to an end around 130 millennia BP with the gross of centuries or so known as the Eemian or Ipswichian, during which sea level rose to six to nine metres above where it is today. Ice ages during this time are much longer than interglacials, which all seem to last about that long, which also means we’re kind of due for a new ice age, hence Nigel Calder’s fixation which I mentioned here. This is the period during which anatomically modern humans evolved, and our split between Asian and Afrikan populations. During this time there were hippos in the Thames and Rhine, and there were also straight-tusked elephants again in Britain, although we were at the limit of their range by then. They finally became extinct, or perhaps just left, at the start of the next ice age, the Weichsel.
The Weichsel, which is the most recent ice age and the one many probably just think of as the Ice Age, was less severe than the Saale, with the ice sheets only reaching as far south as the Humber and Mid-Wales, and across in Ireland in a line across from Wexford to Galway. South of those would’ve been tundra rather than actual permanent ice cover, and there were reindeer in the Peak District who used to migrate to Lincolnshire to calve. There were also still mammoths, for instance in Shropshire, until 14 000 BP, although they had previously been wiped out here because it was too cold for them. What seems to have been happening here is that local populations of mammoths were dying out and then getting replaced by others moving into the area, in a cycle. There were also bison, woolly rhinos and Irish elks. The last seem to be remembered in Irish legends. They were not closely related to elks but to fallow deer, and their last representatives vanished around 7 700 BP in Russia, at a time when mammoths were still around – they only died out around the time the pyramids were built. Irish elk appear in cave paintings and were hunted by humans.
The Holocene is actually formally defined, kind of by fiat, rather than just being the end of the last ice age. In the 1990s CE, it was proposed that a Holocene calendar be formally designated where years are numbered from the start of the epoch. Hence it started officially in 10 000 BCE or 11 950 BP. This makes it easier to use for geology and archæology, since Bede’s timing for the birth of Jesus is both arbitrary and culturally biassed, and not very useful for these purposes except that it helps us relate to the dates if one has a Christian background. That said, the onset of the Holocene is also the time of the last glacial retreat, and as such dates to around 11 650 years ago, or 9 630 BCE with spurious accuracy. All human recorded history has taken place in this period, and during this time there has been fluctuation in climate, here and elsewhere.
A big factor in the Holocene was the Bond events, which are fluctuations in ice rafting occurring from the Arctic in an approximately ten century cycle. In terms of the Common Era, these nine events took place at the following approximate dates: 9100 BCE, 8300 BCE, 7400 BCE, 6200 BCE, 3900 BCE, 2200 BCE, 800 BCE, 600 CE and 1500 CE. Some of these are associated with particular historical events or trends. What seems to be happening, and this is my interpretation, is that Arctic ice breaks up and spreads out in the North Atlantic, reflecting more heat back into space and cooling the planet globally. Then it refreezes and the planet warms up due to a smaller area being covered by ice.
The events in question sometimes had a major effect here, sometimes either not or not in a discernible way from this distance in time. Before I go on, I’ll talk about Doggerland, the formation of the Irish Sea and the English Channel. Doggerland, as you must surely know but I’ll mention it anyway, is the area now flooded by the North Sea. The Irish Sea used to be a marshy area with some lakes, the English Channel was also above sea level and even after the rest was submerged there was a narrow isthmus across the Pas De Calais until 5000 BCE. All of this was to do with ice melting and sea level rise.
Where the Bond events didn’t directly influence the climate significantly in this country, and in fact they would’ve done although without agriculture or written records the traces are harder to discern without some archæological research such as looking at tree rings, they may still have had a long-term knock on effect from what happened elsewhere. For instance, the 6200 BCE event led to a drier spell in Mesopotamia and therefore may have triggered irrigation efforts which led to the emergence of Sumer and the other cultures in that area, ultimately leading to the arrival of more advanced technology and different peoples here in the characteristic pattern where the East is south of the West. That said, the distribution of the aforementioned elephants also shows a northeast-southwest boundary and the glaciation kind of followed the same “diagonal” line. The 3900 BCE event led to the reformation of the Sahara Desert by four centuries later, whose effects can be seen in rock paintings showing animals usually found in wetter climates in that area. The Bronze Age began a couple of centuries after that. This got to Britain about a millennium later still. A later significant oscillation was the Iron Age Cold Epoch, which started around 800 BCE and coincided with the expansion of Ancient Greece and the foundation of Rome. This was followed by the Roman Warm period from 250 BCE to 400 CE, or 500 to 1150 AUC in the Roman dating system, which seems to have been fairly local, i.e. confined to Europe. Italy at the time was wetter and cooler, and it was the start of the current Subatlantic period. The temperature left to itself is slightly lower in this, current, period, than its predecessors and again this is evidence that we’re due an Ice Age, but human activity seems to be either postponing or preventing this for now. The cooling is thought to have triggered the migration of the Germanic tribes from Scandinavia down into the main part of Europe. There are then a number of named periods: the Late Antique Little Ice Age, Dark Ages Cold Period, Mediæval Warm Period and finally the well-known Little Ice Age.
The first two of these coincide to some extent, with the Late Antique Little Ice Age occurring in the middle of the Dark Ages Cold Period. In other words the former was the peak of the latter. The longer period seems to be precisely dateable to 509-865 CE, and includes for Britain most of the sub-Roman period, Augustine’s arrival and the early years of Alfred’s life until shortly before he became King. The middle of that period seems to have been worsened by volcanic eruptions reducing sunlight. The Annals of Ulster record a crop failure leading to a lack of bread in 536 and those of Innisfallen says this continued until 539. Ice cores from those years show a higher sulphur content than others. The Annales Cambriæ record “great mortality in Britain and Ireland” and also say it was King Arthur’s last battle. In various places it’s said that the Sun shone only weakly for a year and a half. In China it snowed in August 536.
This was eventually followed by the Mediæval Warm Period, lasting from around 950-1250. Sediments in the Sargasso Sea show that it was 1°C warmer than 1996 at this time. It seems that the ice-free seas of the North Atlantic were taken advantage of by the Norse people to colonise Greenland, as they called it, and Afrika was drier. After a bit of a gap, the Little Ice Age began in about 1350 and lasted up until about 1900, and this is something I find puzzling. There was a major famine here in 1315-17 which seems to have set Europe up for the Black Death later in the century because the people who were children at the time of the famine seem to have grown up rather unhealthy, laying them and the communities around them open to the ravages of the plague, if that’s what it was, as adults, and also making them a source of infection for healthier people who might otherwise have escaped. It might be expected that this was due to a series of years with bad weather conditions for growth of wheat in particular because of the climate, but in fact this doesn’t seem to be so. However, it does seem that a five-year long series of eruptions in Aotearoa/New Zealand of Mount Tarawera may have precipitated the event. Some people do extend the Little Ice Age back to 1300.
The following few centuries had such features as white Xmases and frost fairs on the Thames. There are two reasons why white Xmases used to me more frequent. One of them is pretty obvious, but the other, so I hear, is that there tends to be a snowier period shortly before the dates which are now celebrated as Christmas, and the calendar reforms moved it out of this to a less snowy stage of the winter. I’m not sure about that because it seems more likely to snow in early January than mid-December, so it seems to be in the wrong direction.
Frost fairs were held on the Thames in London from the seventh to the nineteenth centuries CE, peaking from the seventeenth century onward when the Little Ice Age was at its most severe. It’s thought that the Thames was more likely to freeze over in any case back then because of the water wheels under London Bridge slowing the flow of the river down and the pollution in the water raising the freezing point. They were in any case quite seldom held, and were much more common elsewhere in Europe. The Thames has frozen over further upstream much more recently, unsurprisingly in winter 1963. I can remember the sea freezing over to a limited extent in the Thames Estuary. It froze over for several weeks in London in the third Christian century, and in 695, the date of the first fair, then there’s a gap until 1608, when it first used name. The biggest was in 1683-4, when the ice was half a metre thick. The last one was in February 1814, when the ice supported an elephant. I don’t want to ignore the cruelty of exploiting a presumably Asian elephant in that way, but note the connection with native British straight-tusked elephants living on the banks of the river in ages past. In 1831, London Bridge was pulled down and the climate was warming, meaning that it ceased to be feasible from that point on.
Approaching living memory, there’s the Year Without A Summer, also known as “Eighteen Hundred And Frozen To Death”, a phrase many older people may have heard of. This is 1816. The 1815 eruption of Mount Tambora in today’s Indonesia led to a global fall in temperature of 0.7°C. The summer temperatures were relatively lowest in France and England. There was food price inflation all over Europe and in 1819, there were typhus epidemics in Ireland and Scotland as a result of malnourishment. Mary Shelley wrote ‘Frankenstein’ during the summer of this year because the weather was too bad for them to go outside. Also by this time, sunspots were being observed and the Sun’s surface was unusually “clean” between 1796 and 1820, a period known as the Dalton Minimum, and like other minima it coincided with a spell of colder temperatures. The better-known Maunder Minimum from 1645-1715 had also seen this, and it’s also hypothesised that there’s a rhythm instantiated by these two, meaning that an earlier Spörer Minimum had occurred from 1460-1550.
There are several ways to retrieve the record of climate change in fairly recent times, including ice core samples, tree rings, coral skeletons, cave deposits and foraminiferan skeletons from the sea bed and chalk. One of the things these show is that the industrial revolution, which at the time was fuelled by coal, began to make its presence felt by about 1830, rather surprisingly in the Southern Hemisphere more than the Northern. Antarctica has been protected from much of this by the circulation of water and air currents in the Southern Ocean, but it can be seen in other oceans and landmasses south of the Equator.
This is more or less common knowledge, so I won’t go into much depth, and I’m pretty sure I’ve covered it extensively elsewhere on this blog. Therefore I’ll just mention three events: the winters of 1947 and 1963, and the summer of 1976.
From 23rd January 1947, Britain and the rest of Europe experienced an unusually harsh winter, which incidentally is a major plot point in my novel ‘1934’. I also know someone whose life was basically ruined by it. An anticyclone was stationary over Scandinavia, preventing low pressure areas from moving towards Britain from the Atlantic and allowing winds to blow from the east across the country. The temperature dropped to -21°C, there was pack ice in the Channel and ice floes in the North Sea. Similar, and in some cases more severe, measures were taken as during the War, including lower rations, the suspension of television, the reduction of radio and there were power cuts which even affected Buckingham Palace. Four million people claimed unemployment benefit. Three million sheep died, there were many crops lost or irretrievable from the ground due to frozen soil and there were of course many human casualties. This was followed by serious flooding in March when the snow and ice melted.
The next severe winter occurred sixteen years later, and Sarada can remember this although I wasn’t born. This was known as the Big Freeze of ’63 and was the coldest since 1895. The situation began similarly to 1947 with a stationary high over Scandinavia, but this was then replaced by another over Iceland. Temperatures fell to -19°C in Scotland and the sea froze over at Herne Bay for 1.6 kilometres. January 1963 is the coldest month since January 1814. The difference between the two post-War winters is probably down to the fact that Britain had recovered economically from the War by the second, and there were also some advances in technology and the infrastructure, but that’s just my guess.
Finally for today I want to mention an incident which I can actually remember quite clearly: the summer of 1976. Although this was only the second driest summer since records began, next to 1995, it’s far more memorable for its weather than the later one. You may recall, incidentally, that 1975 was also very hot and dry, and that dryness and mildness continued through the ’75-’76 winter, meaning that more insects survived and continued to reproduce in the next year. Meanwhile the water reserves were already unusually low. The cause of the actual heatwave and drought was, surprisingly, similar to those of the winters of ’47 and ’63, with a high pressure area stuck over Europe, and in fact the whole of Europe was affected, not just Britain. Shade temperatures rose to 34°C in late July. Rivers, lakes and reservoirs dried up, the grass died and there was a plague of ladybirds. It was actually possible to fill shovels with them, and many people, including myself, discovered for the first time that they “sweat” an irritant clear yellow liquid when stressed (incidentally the same thing happened a couple of days ago to me while I was out). This was because ladybirds are predators of other insects, and their plethora had led to a population explosion. There were also standpipes in the street due to a water shortage, and I think hosepipes were banned for the first time. The Archbishop of Canterbury prayed for rain to no avail. Then, bizarrely, the Prime Minister Harold Wilson appointed a minister for drought, Denis Howell, and ordered him to do a rain dance! Then it rained and he became minster for floods. I shall now specifically invite Steve to tell us his tale of ’76.
As for me, my tenth birthday occurred during the drought. I was on holiday in the Isle Of Wight and my brother and I both went down with tonsilitis. My temperature went up to 38.3°C. However, I recovered in time to enjoy the rest of the holiday, and we went to Blackgang Chine where there was a “ride” purporting to be Hell which was very hot inside, except that it wasn’t because of the temperature outside. Two other notable features were that after it had started raining people were still using standpipes and were actually standing in the rain waiting for water, and it was stated that even if it rained every day until the year 2000 there wouldn’t be enough water to replace what there had been in 1974. There was also said to be a problem with the mud getting baked into an impermeable condition, such that the rain would just run off and fail to accumulate. There were forest fires in the South, and everyone was warned to take extreme care. However, these have actually served to replenish heathland in the long run. Deaths went up by twenty percent.
That, then, is the history of climate in this country from the life of Swanscombe Woman four hundred millennia ago into the late twentieth century. Tomorrow I will cover the history of climate here from deep in prehistory up until the advent of the latest spate of Ice Ages.