Frozenology

Tony Wood reports from Siberia

The corridor we are standing in bristles with ice. Thick layers of what turn out, on closer inspection, to be delicate, hexagonal crystals line the walls and ceiling. I and a handful of other visitors are in the basement laboratory of the Permafrost Institute in Yakutsk; according to the red numbers of an LED panel, the temperature is -8 °C. After a few minutes, our presence – breathing, talking – has raised the temperature to -7 °C, and we are ushered back to the surface, where it is 35 °C, a day of dazzling Arctic sunshine and heat that makes the skin prickle.

Here, as elsewhere in Russia, it has been a searing summer, turning large swathes of the landscape into kindling. The apocalyptic scenes in European Russia – thousands burned out of their homes, millions of hectares of crops destroyed, Moscow wreathed in smoke from smouldering peat bogs – have dominated news reports. But vast areas of the Far Eastern Federal District were damaged too: on 31 July, for example, the Ministry of Emergency Situations reported fires occupying more than 5600 hectares. On the hillsides to the south-west of Yakutsk, six-foot-tall wooden letters spell out messages warning passing motorists of the dangers of forest fires, though some of the letters have fallen down or been removed, scrambling the words beyond comprehension.

Underground, however, it is always winter in Yakutsk. The city lies at the centre of the world’s coldest inhabited region, the Sakha Republic. Known until 1990 as Yakutia, after the Russian term for the main local ethnic group, Sakha is the largest of Russia’s federal sub-units, covering an area of three million square kilometres; it is also among the most sparsely inhabited, with a population density of 0.3 people per square kilometre. In tsarist times Yakutia was, like the rest of Siberia, a place of exile: Decembrists, Polish rebels, Narodniks and Social Democrats were among those sent here, to a prison so remote and exposed to the elements that it had no need of walls. Two of Sakha’s towns have a claim to be called the ‘Pole of Cold’, having registered temperatures of -68 °C – the lowest recorded at normal altitude outside Antarctica. In Yakutsk itself, the annual average temperature is around -8 °C, and the January average -40 °C.

The city lies in the valley of the broad, slow Lena river, and is bounded to the west by a low ridge, bare of trees; these tend to grow only where there is shelter from the punishing winds. (You can get an idea of the generic Sakha landscape from the word alaas, often translated as ‘homeland’, but which literally means a clearing surrounded by trees, usually with a pond in the middle.) Yakutsk today has a population of around 250,000, composed of roughly equal numbers of Sakha and ethnic Russians, though other former Soviet nationalities are also represented – Central Asian migrants, for example, working on building sites. On the streets, the tumbling Turkic syllables of the Sakha language mingle with the sounds of Russian and Tajik. The city was originally a fort founded in 1632 by a Cossack expeditionary force in search of furs. Letters to Moscow from the settlement’s early military governors indicate how inhospitable the tsar’s new outpost was: in 1640, a dispatch advised the sovereign ‘not to hope for wheat’, since ‘the earth does not thaw completely even in summer’; in 1686, after several failed attempts to dig a well, a later voevoda observed more precisely that the ground thawed to a depth of no more than two arshins (1.4 metres), ‘and below that the earth is always frozen.’

The Cossacks had discovered what we call permafrost. The English word, according to the OED, was coined in 1943. The Russian term, vechnaya merzlota – literally ‘eternal frozen ground’ – is older, and seems to have entered the scientific lexicon from popular parlance in the mid-19th century. Russia’s scientists, geographers and explorers had long been interested in the phenomenon: in the 18th century, Mikhail Lomonosov, the father of Russian science, had sought to explain the existence of soils that remained frozen all the year round. He also received reports of ‘strange, great animals, like elephants’ found buried deep in the ground. It was probably the repeated discovery of preserved mammoths that gave rise to the designation ‘eternal’: the unearthing of a frozen prehistory in Siberia was the equivalent of Victorian England’s encounter with geological time on the Dorset coast. In the 19th century there were attempts first to measure the extent of the permafrost, and then to master it: explorers such as Karl Ernst von Baer, Ferdinand von Wrangel and Alexander von Middendorff (many were Baltic Germans, for some reason) were succeeded a generation later by engineers planning the route of the Trans-Siberian Railway. The Permafrost Institute was founded in 1941, by which time Soviet scientists had developed a discipline – merzlotovedenie, or ‘frozenology’ – devoted to what became known as the ‘cryosphere’.

Their research is responsible for one of the most distinctive features of Yakutsk. The majority of its large buildings are raised three or four feet from the ground, standing on dozens of concrete stilts: local government offices that take up an entire block, six-storey apartment buildings, a sizeable new Orthodox seminary currently under construction, even a hulking factory at the city’s edge. It gives the place a tentative feel, as if it were perching on the soil like a bird on a branch. The purpose of the stilts is to prevent heat from the buildings warming the ground, since this would melt the icy soil on which their foundations rest, causing them to sink. The wooden houses that remain in the centre of the city, and the many more that make up its poorer outskirts, show the wisdom of the new pile technique: you can tell the age of a building by how close to the pavement its windowsills have sagged. Snaking in between the buildings, throughout the city, are pipes carrying gas and steam from the centralised heating system; these too are carried above the ground on concrete piles, bending into improbable shapes to arch across streets.

The lurch between high heat and deep cold – the span between winter minima and summer maxima here can be as great as a hundred degrees – is enough to test, and often break, the infrastructure and machinery. The strains of the climate have caused many houses to buckle, creating a landscape of undulating wooden roofs and walls. Uneven summer thawing can cause the ground to disappear from under all or part of a building; since 1970 some 300 buildings have collapsed, and the rate at which this kind of subsidence occurs has been increasing since the start of the 1990s. This is a worry, given that only 3000 buildings in the city are not made of wood.

Is this yet another symptom of climate change? Some in Yakutsk blame flaws in the construction and planning of these particular buildings, while others point to the localised warming effect that any building has on the upper layers of the permafrost; only a small minority ascribe the problems to planetary climate shifts. Even the 2009 Greenpeace Russia report, from which I have taken my figures, strikes a cautious note, saying only that global climate change must ‘surely have played a role’. The hesitation illustrates the way in which Russian perceptions of the phenomenon differ from those in Western Europe or the US. Media coverage of this summer’s extreme heat provides a further example: in the West, it now appears obligatory for reports on such dramatic anomalies to refer to climate change – usually to suggest that they are just a taste of bleaker things to come – but this motif has been largely absent from the Russian press. If anything, the media have tended to play down the extraordinariness of the heat: in mid-July, Ekspert magazine described the current drought as a trifle compared to the zasukha of 1972, let alone those of 1891 and 1921, and noted that Pushkin and Gogol would generally have experienced hotter summers than this one.

The severity of this summer’s wildfires may ultimately shake the complacent into changing their views. Medvedev’s statement on 30 July that the fires sweeping the country were a consequence of climate change was perhaps an early example of this, but for the moment sceptical voices are not in the minority, among Russia’s officials or the general public. In October 2009, the state-owned Channel One broadcast a documentary, The History of a Deception, which argued that climate change is the creation of a media conspiracy fronted by Al Gore. Much of the Russian public shares this suspicion of the ecological agenda, which it sees as at best a do-gooding impediment to sales of oil and gas. There is also the perception, common in ‘emerging’ economies, that the wealthy industrialised world is now using science to kick away the developmental ladder. Although it was Moscow’s eventual ratification of the Kyoto Protocol that brought it into force in 2005, this was less a sign of green intentions than a consequence of post-Soviet industrial collapse: between 1990 and 2004, the country’s emissions contracted by 32 per cent, enabling it spectacularly to outperform its original target of zero growth. Thus in June 2009, when Medvedev announced Russia’s emissions targets for 2020, he was able effectively to mandate an increase of 30 per cent from present levels, adding that ‘we will not cut our development potential.’ A few months later, in the run-up to the Copenhagen summit, the head of the Russian delegation further exasperated environmental activists by stating that ‘scientific circles in Russia and elsewhere still do not have a united opinion on the causes of global warming,’ and suggesting that an international panel be set up to investigate how far humankind had contributed to climate change (he was perhaps unaware of the existence of the IPCC, set up by the UN in 1988).

Russian scientists are not divided over whether or not climate change is happening. The data speak for themselves: according to Rosgidromet, the state hydrological and meteorological agency, the average annual temperature in Russia has risen by 1.29 °C over the last hundred years, compared to a global average increase of 0.74 °C; the mean warming over the last 30 years is higher still, at 1.33 °C. The divisions concern, rather, the causes and consequences of climate change. Broadly speaking, there are two camps, one stressing anthropogenic factors, the other pointing to longer-term climatic fluctuations on which humankind can have only a negligible impact. The first group warn of drastic consequences from further warming and press for urgent action to reduce emissions; the second maintain that there is no need for such alarmism – Vladimir Melnikov, the head of the Earth Cryosphere Institute in Tyumen, suggested in 2008 that we should all ‘calm down, there will be no catastrophes.’

This second group contains many permafrost experts, who spend their lives analysing soils that have remained frozen for tens of thousands of years, to a depth of hundreds of metres. In Yakutsk, the permafrost is between 250 and 350 metres thick: far deeper than the 28 metres Matvei Kravkov’s men managed to dig back in the 1680s, and more than double the depth of a shaft sunk by a local merchant and amateur scientist called Fedor Shergin between 1828 and 1837. Elsewhere in the Sakha Republic, the permafrost reaches a depth of 1300 metres. It would take hundreds of years of steadily increasing temperatures for the ground here to thaw out completely, a horizon far beyond the reach of existing climate models. Many experts believe that the permafrost will outlast any scenario the IPCC could produce; some even attribute a kind of mystical agency to it – Melnikov told an interviewer that permafrost by its nature ‘resists changes of any kind’.

Yet other Russian experts maintain that climate change has already affected the permafrost. According to Sergei Kirpotin of Tomsk State University, it can no longer be described as ‘eternal’: in many areas, it has become increasingly unstable. Both Rosgidromet and Greenpeace Russia report increases in the temperature of the ‘active’ layer – the upper few metres which thaw in summer – since the 1970s, ranging from 1 °C in the north part of western Siberia to 1.5 °C in central Sakha. The deepening of the active layer, they say, will bring with it a weakening of the ground’s load-bearing capacity, with a consequent risk to buildings, pipelines and roads. In other areas, they foresee the disappearance of the permafrost altogether, resulting in wrenching ecological change (moving treelines, the transplanting of ecosystems), the results of which are hard to predict.

Which of these two currents of thought is right matters a great deal, and not only to Russia. Permafrost takes up more than two-thirds of the country’s territory – an area of ten million square kilometres, the bulk of the land east of the Urals. There are three main types, classified according to the depth and contiguity of frozen ground: continuous, discontinuous and insular. They occur in three concentric areas, with a large zone of continuous permafrost enclosed by a discontinuous band and an outer insular band. Sakha forms the icy core of the first, which stretches from the Yenisei River to the Bering Strait; its southern border runs diagonally south-east from the bottom of the Yamal Peninsula to Lensk on the Lena River, before turning due east across the southern part of Sakha, and then following the coastline of the Sea of Okhotsk at a distance of about 200 kilometres. Further blocs of continuous permafrost occur in the high ground between the north-eastern shores of Lake Baikal and the Sea of Okhotsk. In these areas, the ground is frozen to a depth of at least 100 metres, though in places – Verkhoyansk, for example – it can reach more than a kilometre. Wrapped around this is a belt of discontinuous or sporadic permafrost, which broadens to take in most of the area around Lake Baikal; here the depth of frozen ground generally ranges from 25 to 100 metres. Insular permafrost, which occurs patchily and to a depth of between ten and 50 metres or less, can be found in a swathe of land that includes all of the Kola Peninsula and a portion of the Arctic coast of European Russia, as well as most of the basins of the Ob and upper Yenisei rivers, and the land around the southern tip of Lake Baikal.

Climate scientists are careful not to draw too direct a causal line between an increase in atmospheric temperature and alterations in the thermal regime below ground; they have to take into account such things as soil type, terrain, vegetation and snow cover. Nonetheless, the climatic warming that has taken place to date does coincide with some dramatic changes beneath the topsoil: the 2009 Greenpeace Russia report cites data indicating that over the past 35 years, enough insular permafrost has thawed out to shift its southern boundary northwards by 30-40 kilometres in parts of European Russia, and by 80 kilometres near the Urals.

What might the future bring? In a paper from 2006, Oleg Anisimov (the lead author of the Greenpeace Russia report) and Svetlana Reneva, both at the State Hydrological Institute in St Petersburg, used five different global climate models to project increases in seasonal thaw depth, and to map out the possible contours of near-surface permafrost in years to come. The median scenario, devised by the Geophysical Fluid Dynamics Laboratory (GFDL) in New Jersey, indicates that the active layer could deepen by between 25 and 40 per cent across much of Siberia by 2050, and by more than 60 per cent along the Arctic coast. It envisages a total contraction of near-surface permafrost across the Northern Hemisphere of 11 per cent by 2030, 18 per cent by 2050 and 23 per cent by 2080; in the continuous permafrost zone, it forecasts reductions of 18, 29 and 41 per cent for the same dates. This would mean that by 2080, most of what is now continuous permafrost would have shifted into the discontinuous category, leaving only the cold heart of Sakha undiminished. The cryosphere as a whole would have retreated far behind its present outer limit. Rosgidromet expects the southern permafrost boundary in western Siberia to move northward ‘by 30-80 kilometres in the next 20-25 years and by 150-200 kilometres by 2050’.

This sounds like good news, and in many ways it is. The shrinking of the cryosphere would be accompanied by a softening of the harsh climate in many areas, rendering them far more habitable. There are significant concentrations of population and infrastructure in the areas of discontinuous and insular permafrost, since Siberia’s larger cities are distributed along its southern edge, strung like beads along the great railway line. In industrial centres such as Bratsk and Krasnoyarsk, there would obviously be economic gains from a warmer climate: shorter, milder winters would mean lower expenditure on heating, for example. Rosgidromet estimates that across Russia, on average, heating will be required for five fewer days in 2015 than it was in 2000. More land would be available for cultivation, and the growing season would lengthen; Rosgidromet looks forward to the sugar-beet line marching northwards. Then there is the matter of the natural resources that may be stored in previously inaccessible ground. Arctic regions already supply more than 90 per cent of Russia’s gas and three-quarters of its oil, along with considerable quantities of the world’s nickel, cobalt, copper and diamonds. Climate change could well bring further prizes within reach.

There are plenty of dangers to be weighed against such benefits. The thawing of the permafrost would be far from even. The varying character of the soil – its density, porosity, ice content – would produce wildly different outcomes from one patch of ground to the next. Whole areas could simply collapse as soon as the ice underpinning them melts away. According to Kirpotin, parts of western Siberia have already witnessed the rapid formation of what is called ‘thermokarst’, by analogy with the perforated karst landscapes produced by weathered limestone. Such changes pose a serious threat to human infrastructure – apartment blocks, schools, factories, offices. Anisimov and Reneva constructed a ‘hazard map’ based on the GFDL model to identify where buildings are likely to be in the greatest danger. The high-risk areas include most of the Arctic coast and a band stretching along the cryosphere’s present southern edge, from the Kola Peninsula to Lake Baikal, which includes large cities such as Murmansk, Irkutsk, Chita, Blagoveshchensk and Komsomolsk-na-Amure, as well as much of the oil-producing Tyumen region, which in 2007 accounted for almost 10 per cent of Russian GDP. Indeed, the same dangers threaten Siberia’s oil and gas pipelines, which, according to one estimate cited by Greenpeace Russia, comprise a network with a total length of 350,000 kilometres. Thousands of accidents are caused each year by deformations or subsidence in the ground supporting the pipelines; many of them can be put down to heat spreading to the soil from the pipes, but the figure can only increase if the landscape undergoes the dramatic changes predicted by climate modellers.

Thawing permafrost wouldn’t only transform the ground on which Russia stands: it could also alter the composition of the Earth’s atmosphere. Much of Siberia consists of swampland – especially in the west, where the watershed of the Ob contains an estimated one million square kilometres of bog. This includes the Great Vasyugan Mire, the largest single peatland in the world, with an area of 68,000 square kilometres. Viewed from the air, the land around the middle reaches of the Ob looks like an enormous stretch of green baize, riddled with the blue-black holes of ponds and ox-bow lakes; rivers meander to the horizon in long, broad striations. Since the discovery of oil under Lake Samotlor in the 1960s, this waterlogged plain has been Russia’s principal source of export earnings. Cities such as Nefteyugansk and Nizhnevartovsk sprouted along the Ob’s banks, and have been growing rapidly since the 1970s. Beneath the surface of western Siberia, according to Sergei Kirpotin’s calculations, somewhere between 50 and 70 billion tonnes of carbon are stored. This is around 26 per cent of the carbon so far accumulated by terrestrial ecosystems.

Most of this ancient carbon is currently locked away in frozen soil under lakes, ponds and rivers. But the retreat of the cryosphere could result in the release of millions of tonnes of it in the form of methane. There are also large quantities of methane deep in the Arctic Ocean, trapped under the frozen sea floor or in ice crystals, which could bubble to the surface in the event of further warming. Methane is a far more potent greenhouse gas than carbon dioxide, and could have a significant ‘forcing’ effect on the global climate while it remains in the atmosphere; some scientists fear it could tip us over a warming threshold that it might otherwise have taken decades to reach. At present, the mires and bogs of southern Siberia act as a net carbon sink, drawing in carbon dioxide from the atmosphere as they continue to expand. But in the north, the thawing of Arctic permafrost and the warming ocean are releasing methane into the atmosphere in as yet unknown quantities.

Scientists differ as to the extent and impact of these methane emissions, both now and in the futures projected by global climate models. Anisimov and Reneva, for example, calculate that by 2050, methane emissions will increase by perhaps 50 per cent along the Arctic coast, and by 30-50 per cent in the discontinuous permafrost zone; in the West Siberian plain, where the largest concentrations of stored carbon lie, there will be a 20 per cent increase. According to Stephen Sitch of the Met Office’s Hadley Centre, the gradual seepage of methane from Siberia’s permafrost could effectively double atmospheric levels of the gas, leading to an increase in global warming of 10-25 per cent over the next century. Anisimov, on the other hand, is convinced that the total contribution of methane emissions to rising temperatures will be negligible, arriving at a figure of an extra 0.012 °C by 2050. Rosgidromet agrees: its 2008 report asserted that increased methane emissions from Siberian wetlands and thawing permafrost ‘will not have any impact on the global climate’.

However, these conclusions rest on very patchy data. This is partly because so many of the sites are so remote. The Arctic seas may be contributing far more methane than previously suspected: in March 2010, a team led by Natalia Shakhova and Igor Semiletov argued in Science that the East Siberian Arctic Shelf, a vast area that includes the Laptev Sea, the East Siberian Sea and the Russian portion of the Chukchi Sea, contains very large quantities of dissolved methane. They calculate that in the shallow reaches of this shelf, the amount of methane emitted every year is around eight billion tonnes, ‘of the same magnitude as existing estimates of total methane emissions from the entire world ocean’.

There is a problem, too, with methods of measurement. Satellite imaging can tell us much, but not about the quantities of greenhouse gases emerging from Siberian thaw lakes. Instead, scientists have tended to gauge the ‘respiration’ of gases from the water’s surface, then extrapolate from this to arrive at more general estimates. But fieldwork by Russian and American scientists in northern Chukotka suggests that steady upward diffusion is not the way in which most methane is emitted. According to research published in Nature in 2006 by a team led by Katey Walter and Sergei Zimov, the vast bulk of methane emissions comes in the form of ‘ebullition’ – concentrated bursts of gas that cause bubbles to form in ice, or else prevent areas of water from freezing over at all. They calculate that we may have to increase current estimates of methane emissions by between 10 and 63 per cent. If they are right, the thawing of the permafrost could unleash large bursts of methane into the atmosphere, to unmeasurable effect on the global carbon balance. We could be pushed across the next threshold of global warming at any moment. Or it may already have happened: perhaps somewhere in the vast unpeopled expanses between the Urals and Alaska, a 40,000-year-old cloud of gas is already silently remaking our future.