Chapter 6

One Hundred Metres

Many years ago, and it does seem like an age, I was obsessed with geography at school. There really wasn’t enough information in those early teenage years to satisfy my interest, but what there was I rapaciously gobbled up. I think it was the words that did it; new, wonderful words like Hinterland, Thalweg, Tropics, Tundra, Taiga. Taiga was my favourite, an immense word bringing to mind an ancient, tangled and wild environment that should never be set foot in. The word is Siberian, possibly Mongolian, and seems to just mean, “wild forest”[i]. The originators of that word must have lived in such an environment all their lives and, to them, it was their life: their world.

The Taiga stretches across the northern hemisphere in a vast swath of spruce, pine, larch and fir, enveloping much of northern Canada, Lapland and the entire length of the Russian nation, often taking great excursions southwards where the dry continental heart is a savage environment for lush grasslands. The Eastern Siberian Taiga alone is a continuous forest 3.9 million square kilometres (1.5 million square miles) in area[ii] – that is as large as India and Pakistan combined. This is worth repeating: the Eastern Siberian Taiga alone is as large as India and Pakistan combined.

In July 1908, at the heart of this vast tract a mighty explosion threw down millions of trees, scorching the ground for miles around:

I do not remember exactly the year, but more than twenty years ago during ploughing season, I was sitting at breakfast on the house porch at Vanavara trading post facing North. I suddenly saw that directly to the North, over Onkoul's Tunguska road, the sky split in two and fire appeared high and wide over the forest. The entire Northern side was covered with fire. At that moment I became so hot that I couldn't bear it, as if my shirt was on fire. I wanted to tear off my shirt and throw it down, but then the sky shut closed.[iii]

It was not until 1921, following a decision by the then Soviet Union to become a force in the scientific world, that Leonid Kulik, a Russian mineralogist, was commissioned to find the source of the explosion. It would take him until 1927 to find the crater, along with the arboreal destruction that spread out for miles: “The huge trees of the taiga lay flat. Pines, firs, deciduous trees; all had succumbed. The sharp outlines of the winter landscape etched it like a plate.”[iv] Nearly six years to find a disc of devastation perhaps seventy miles across; this surely says something about the size of the area being surveyed.

Yet this dark vastness that defines entire landmasses is now under attack from a multitude of sources: the loggers that think nothing of penetrating its mysteries to feed our ravenous appetite for timber, woodchip and paper; the changing rain and snowfall in places flooding out stable soils, and in others desiccating the land; the acid rain that still falls on the branches, stripping them bare. And who would have thought that such an expanse, containing some of the largest living organisms in history – some weighing in excess of a thousand tonnes – could be brought to heel by a tiny beetle measuring just five millimetres in length?

Even the magical word Taiga is dropping out of favour, to be replaced by the term Boreal Forest. Still evocative: but as with the Victorian habit of replacing the ancient Celtic names of geographical features throughout Britain with florid descriptive alternatives, when its name is changed, a place seems to lose part of its identity.

What Is A Spruce Tree?

More to the point, what is a tree? In essence, a tree is a living machine that generates energy in order to feed its need to be taller than everything around it. A forest in its natural state is a set of different canopies trying to compete with each other for light, their roots reaching out for nutrients and water; all the time at the mercy of the landscape and the weather. The tallest trees are tremendously heavy, their trunks bound into columns of woody tubes that carry water upwards to the leaves where it takes its part in the photosynthetic process – the conversion of carbon dioxide and water into sugars that the tree uses to build itself; leaf, twig, root and trunk. Photosynthesis is common to all plants. As with phytoplankton, the energy used by the tree comes from the sun; and the by-product is oxygen. Along with their crucial role in building and stabilising topsoil, providing habitats for countless species and moistening the air around them; a waste gas liberated from them through a simple chemical process gives life to every animal on Earth.

It is utterly remarkable, when you think about it, that all animals, including humans, depend on oxygen for life, in return for which they produce carbon dioxide. The carbon added to the oxygen to make this waste gas comes to animals through the consumption of (ultimately) plant matter. This plant matter took its carbon from the carbon dioxide that it absorbed from the atmosphere, which had been expelled by the animals, and in return it produced oxygen, which animals depend on for life. The cycle is so perfect; yet until green plants colonised the Earth, no animal existed – instead, the plants depended on bacteria to produce the vital carbon. For most of history the plants themselves were just microscopic blue-green algae, little more than bacteria. For eighty-five percent of the span of all life on Earth[v] a slow battle took place in which the tiniest puffs of oxygen released by the tiniest photosynthesisers fought to raise the oxygen level against the chemical processes that took the oxygen into every rock in every crevice and every pore.

But eventually the plants mastered the atmosphere and the energy that surrounded them. Now, after numerous turbulent glaciations, the forests are a hard outline of their former lush glory; the oxygen rich world of the Carboniferous[vi] which boasted insects the size of humans, with mosses and horsetails reaching twenty metres or more in height[vii], also produced the vast beds of coal that humans burn with abandon, hardly daring to care that they comprise millions of years worth of photosynthesis, and enough carbon to end our time on Earth forever. The trees do their best to remove the carbon, a great deal of the work being concentrated in the disappearing hearts of the great rainforests of the tropics. The huge Redwoods, the Douglas Firs and the Sitka Spruce – the three largest of all the northern trees – grow more sedately than those in the tropics, taking the carbon they need, storing it out of harm’s way.

The Sitka Spruce is the largest of the many varieties of spruce. If left to thrive it can reach 90 metres, maybe more. The one hundred metres in the title of this chapter may contain a hint of artistic licence, but when compared to any other living things on Earth, the scale of the largest trees are in a category all of their own. Spruce trees form a group of about 35 species of tree, that are part of the greater family of pines, and the order that comprises all conifers on Earth. A conifer is simply a type of plant that produces cones in which its seeds are contained. Spruce are unique amongst the conifers in that they are both evergreen – they do not shed their leaves, or rather needles in any great quantity – and have needles that form spirals around each branch. They are extremely hardy and can be found across the globe, from the USA and Canada, to Norway, Russia, Japan and China.

The great Canadian forests are dominated by just a few species of tree: black spruce, balsam fir, white spruce, larch and white birch[viii]. Of these, the two spruces and the fir are evergreen conifers, constantly renewing the fragrant, acid carpet at their bases. The larch is a rare example of a hardy, non-evergreen conifer, while the birch is a hardy deciduous tree, one of the few that can survive such testing conditions.

It is easy to forget, amongst all the mystery and vastness of the Taiga, that the majority of the northern coniferous forests have only been in existence for a short time. The last ice age only started to dissipate twenty thousand years ago, and the ice was still predominant until about ten thousand years ago. It was not until the temperature and precipitation reached conditions suitable for the growth of large trees that any significant forest growth was possible which makes it remarkable that such a massive area could be fully colonised in such a short time, and with such a richness and diversity of inhabitants. The Taiga is most definitely a product of the changing climate, but itself is now instrumental in improving the stability of the climate that we are doing our best to change.

Locked Away Carbon

Calculating the amount of carbon dioxide locked up in these wooden towers is a fine art, and depends on the age of the trees, their size, their density and, not least, the amount of carbon that would also be released from the soil if these trees were removed – soil is one major type of carbon “reservoir”, forests are another type. The Intergovernmental Panel on Climate Change have produced a detailed workbook and set of guidelines[ix] for calculating the size of these reservoirs, but even they cannot tell you the precise amount of carbon in a forest: for boreal, the estimate is anything between 22 and 113 tonnes of wood per hectare. If we take somewhere in the middle, say, between 40 and 75 tonnes, then we can use this to work out how important the Canadian boreal forests are as a store for greenhouse gases. Wood in trees is about fifty percent carbon[x], which gives between 20 and 37.5 tonnes of carbon per hectare; but carbon is not a greenhouse gas, it only becomes that when it combines with oxygen through burning or decomposition to make carbon dioxide. When that happens you multiply the amount of carbon by 3.6, which gives potentially between 72 and 135 tonnes of carbon dioxide per hectare of forest cut down, burned, consumed or otherwise removed.

The Canadian Boreal forest is estimated to occupy about thirty-five percent of the total landmass of Canada[xi], making it something in the region of 3.2 million square kilometres in area. If we use the IPCC figures, that means that between 23 and 43 billion tonnes of carbon dioxide is stored in just the trees of the forest. This store of carbon slowly ebbs and flows as the forest naturally changes in density, age and species mix, but as long as it remains intact, that carbon largely remains locked away from the atmosphere.

In 2005 Canada produced over six hundred million tonnes of carbon dioxide from the burning of fossil fuels alone[xii] (which doesn’t include any produced by deforestation), so that means that if Canada were to rapidly lose all of its native Boreal forest, the equivalent of about seventy years worth of carbon dioxide emissions would be puffed into the atmosphere in one giant breath of heat trapping gas.

In recent years, the government of Canada has, on paper, stood by its Kyoto commitment[xiii] to cut the amount of greenhouse gases it is putting into the atmosphere, even if that commitment doesn’t stand up in reality. Between 1990 and 2005 the amount of carbon dioxide it produced went up by thirty-five percent. This was not some temporary aberration; the quantity had been going up year after year almost as though no agreement existed at all. When it realised that it was on a hiding to nothing, and that the income from the lucrative oil sands mining in Alberta would make it one of the richest oil producing nations on Earth then it took decisive action – it refused to commit to any reductions in greenhouse gases at all[xiv].

But we mustn’t blame the whole of the Canadian government machine for this, the finger points primarily at Alberta, whose provincial web site balked at the idea of showing the amount of greenhouse gases it had produced over the last few years[xv], instead showing something called “Greenhouse Gas Intensity”. Greenhouse Gas Intensity compares the amount of carbon produced to the amount of money made – the more money made in comparison to the amount of greenhouses gases produced, the lower the Greenhouse Gas Intensity. Apparently, according to the graph shown on the web site, the quantity of greenhouse gases went down by twenty percent between 1994 and 2004; but only when compared to the huge amount of money Alberta is making from oil production. When you consider that Alberta’s Gross Domestic Product[xvi] increased by 3.6 percent per year in the same period[xvii] then it becomes clear that, in fact, Alberta’s greenhouse gas emissions went up by no less than twenty percent. It’s very easy to lie with statistics, but not so easy to hide the truth.

The point of all this statistical juggling is to demonstrate how powerful and potentially dangerous figures can be. It doesn’t take a great deal of effort to show that the provincial government of Alberta is essentially lying about their greenhouse gas emissions. It also doesn’t take a great deal of effort to show that, because Canada’s overall carbon dioxide emissions have been going up by an average of two percent a year, and will almost certainly accelerate as the rush for sand and shale-based oil gains momentum; that the Boreal forests become more important as a carbon sink every year.

Unfortunately, the forests are not remaining intact. I showed in Chapter One that the Central African Rainforest was under extreme pressure from logging and other practices including the mining of mineral resources. The natural Canadian Boreal forest may not have the deeply rich ecological diversity of the rainforest, but neither is it a monoculture plantation of identical trees marching across the landscape in some grotesque military spectacle. The “owners” of plantations in these forests proudly claim the planting of two trees for every one removed – look at the back of a birthday card, or a pad of paper – and they are not lying; yet they fail to explain that those two trees are part of a cash crop, substituting a complex interweaving of dependent species for a desert of quick growing sawmill fodder.

The Canadian Government report to the UN Food and Agricultural Organisation every five years on the state of its forests, yet miraculously have stated identical figures in each of the previous three reports: an outstandingly precise 310,134,000 hectares[xviii]. This has been eagerly seized upon by the Forest Products Association of Canada who state: “If all countries of the world could eliminate or virtually eliminate deforestation as Canada has done, this would have an impact comparable to eliminating fossil fuel emissions in the United States in terms of advancing GHG mitigation efforts”[xix], which would be wonderful if it were true. The FAO, in fact, refer to “the absence of information about forest plantations in Canada”[xx] and go on to state:

Wood removals are declining in Mexico and the United States of America, while they continue to increase in Canada. This trend is reflected in economic data, with modest growth in several economic indicators in Canada and a slight decline in the other two.

Something else in the FAO report caught my eye, too. It is in a section called “Forest Health and Vitality”. British Columbia, it seems, is undergoing its own logging frenzy, not for economic gain, but to protect against potential economic loss. “The Government of British Columbia has dramatically increased logging in an attempt to slow the spread of the beetle by removing recently infested trees and to recover value from trees already killed.” If BC is indeed logging to protect its future, then somewhere else trees are having to be planted at a rate sufficient to keep up with this; which means that the age and diversity of the Boreal is taking a direct hit, and the Canadian Government are making bare-faced lies about the state of this mighty ecosystem.

There also seem to be some big problems with beetles.

Racing To The Pole

The story of the Tortoise and the Hare[xxi] has a nice moral: slow and steady wins the race in the end. There are a couple of flaws in the telling of the original fable, though. First, can you imagine what Aesop would have felt had it turned out that the finish line had been reached before the hare took his first nap and, in fact, the hare was just enjoying a well-earned victory bask under a tree? Second, what if both protagonists were being chased by a hungry man with a big gun? I guess the hare would feel pretty good knowing that he had a shiny gold medal and that he wasn’t going to be turned into hare pie. Poor tortoise.

Aesop was trying to make the point that many humans have a tendency to rush into things with their eyes closed, and end up not seeing the bigger picture; which is a good analogy for how the world has ended up being on the cusp of global environmental catastrophe. It seems, though, that the more power and wealth an individual has, the more tortoise-like he becomes where issues of genuine global importance are concerned. When faced with the need to take rapid action by which such a catastrophe might be averted, then the “tortoise” becomes rather shy. By the time he eventually slides his head out of the shell, looks around and says, “Now then, what’s going on around here?” the climate is changing, and everything is sliding in a giddy, untidy mess towards the brink. Meanwhile the tortoise has decided to sit down with the other tortoises and have a good chat about it.

Some races can’t be measured on a stopwatch, and have little entertainment value for enthusiastic crowds; but they are happening, whether we like it or not. Imagine a great rolling race between three heavyweight contestants: three giants of environmental change that, between them threaten to gobble up enormous areas of habitat and change the face of the Earth. Please allow me to introduce them.

Contestant One is the Industrial Logger. We met him, earlier. Armed with mechanical harvesters, feller-bunchers and bulldozers for that tricky undergrowth, and backed by friendly governments, he spends his time punching great holes in the forest and stripping down habitat leaving piles of broken scrub and huge geometric areas of infertile, acid soil in his wake. You can find them located all over the globe, wherever money can be made from wood. Because of Europe’s centuries old appetite for vast amounts of timber and paper – an appetite unfortunately not matched by any desire to preserve nature – only five percent of Scandinavia’s forest remains in its native state, the rest being little more than plantation[xxii]. The “timber frontier” is now encroaching on the Siberian Taiga: in the ten years up to 2006, the timber production of the Russian Federation rose by 41 percent[xxiii]. As we have seen, the Industrial Logger has a tendency not to tell the whole truth about his activities.  

Figure 8 : Equipment used by Contestant One -- John Deere 959J Tracked Feller-Buncher (Source: Deere & Company Website)

Contestant Two are the Bark Beetles. Weighing in at around one gram and with a nose to tail length of 5mm, they are nonetheless true giants in terms of impact and numbers. Dendroctonus micans, the Spruce Bark Beetle, tunnels into the living bark of spruce trees to form galleries where their larvae feed and develop, ultimately killing the tree[xxiv]. In Alaska alone, the beetle is spreading at a terrific rate, occupying 120,000 acres of forest in 2006, an increase of 68 percent over the previous year[xxv]. Bark beetles are very picky about what they eat, but in large areas of forest that contain a limited number of tree species that is not a problem for them. The 2006 outbreak of Mountain Pine Beetle – another type of bark beetle – in Colorado, USA, only affected lodgepole pines of a particular age, and no other trees; nevertheless 4.8 million of these trees were killed in that year, and expectations were that the entire 1,000 square mile (2,590 square kilometre) area of lodgepole pines in Colorado would be destroyed, with another 36,000 square miles further north and west in similar peril[xxvi]. 

There are a number of factors that affect the likelihood of bark beetle attack. The age of the tree is quite important: the thick bark of older trees provides some resistance, but thick bark also tends to be more fractured, allowing the beetles easier access; older trees also provide much more scope for mass breeding, given the volume of wood available. Another effect of age appears to be the amount of resin a tree is capable of producing: younger trees tend to be more adept at producing resin. Copious production of resin upon attack has been shown to be a tree’s best defence against bark beetles[xxvii]. Overall, old, large trees are more vulnerable to attack than young ones, which makes the impact of the bark beetle particularly significant in terms of scale. Resin production is something also affected by the health of a tree: the Colorado attack followed a long-term drought, leaving the trees unable to produce sufficient sap. There is also a situation where we can once again use the concept of Degree Days.

Remember in Chapter Three, we found that the amount of time the temperature stayed above a certain threshold allowed the calculation of the speed at which a nematode could grow and reproduce. The same applies to bark beetles. According to a report from 2004: “The spruce bark beetle is strongly affected by the ambient temperature. A higher frequency of storm damage events and a higher temperature can increase the risk for a build up of a large population.”[xxviii] High temperatures can bring out the worst in bark beetles. Storm damage is an important factor too, for a dead tree is not able to produce sap, making itself a perfect habitat for bark beetles. As the IPCC has shown, time and time again, storminess is something that is bound to increase with climate change in the future, leaving larger swathes of dead trees and thus, when combined with the steadily rising temperatures of the Taiga, a wonderful springboard for bark beetle infestation to spread further and further across the land.

Figure 8 : Contestant Two -- Dendroctonus micans, the Spruce Bark Beetle. (Source: UK Forestry Commission)

Contestant Three is Climate Change itself. The bark beetles are enjoying the benefits of rising temperatures – basking in the extra degree days and occupying the storm-damaged timber; but with climate change also comes changes in precipitation, increasingly early snow melt, and a whole world of pain for species adapted to very specific climatic conditions. As temperatures increase, the whole broad band of Taiga is creeping northwards: abandoning land in the south and occupying land to the north that was once the sole preserve of sturdy lichens and mosses. Given the potential scale of the shift, this is one of the more sinister impacts of climate change:

Evidence of recent vegetation change is compelling. Aerial photographs show [that] along the Arctic to sub-Arctic boundary, the tree line has moved about 10 km northwards, and 2% of Alaskan tundra on the Seward Peninsula has been displaced by forest in the past 50 years. [xxix]

Ten kilometres in fifty years doesn’t seem terrifying, but then these impacts are the result of a mere 0.7°C increase in global temperatures, and way ahead of any feedback loops kicking in. If you recall, the melting snow in Aspen revealed a land surface that had a far lower albedo; it reflected less energy, and allowed the ground to absorb more. The same albedo effect happens when coniferous trees move into previously scrubby, snowy areas, like the Tundra – an area of almost permanently frozen sub-soil to the north of the Taiga. It turns out that the Taiga absorbs between three and six times as much solar energy as the Tundra[xxx], creating a positive feedback loop that increases the temperature of the Earth’s surface, which in turn causes a further northward shift in the Taiga. If the Taiga remained in the south, the additional extent of forest might offset the reduction in albedo, but as temperatures increase, droughts and outbreaks of forest fires[xxxi] also become more widespread, precisely where extra forest would be most beneficial

Using methods that calculate the area of climatic zones based on temperature, Muyin Wang and James Overland have estimated that the area of tundra lost worldwide between 1980 and 2000 was 1.4 million square kilometres, or twenty percent of the total[xxxii]. That would be bad enough in most natural habitats, but here we are also looking down the barrel of a methane-filled gun.

*   *   *

Beneath the Tundra, deep within the permafrosts of Siberia, northern Canada and Alaska, lie structures known as clathrates. These are tiny pockets of frozen methane ensconced in the sub-soil that, due to the millions of square kilometres of land under constantly frozen conditions, lock away vast amounts of this potent greenhouse gas. Some estimates suggest that beneath the Siberian permafrost alone there are 70 billion tonnes of methane[xxxiii], only prevented from escaping through the chance encounter of methane gas with innumerable minute ice caskets. The release of such a huge amount of gas (it has at least twenty times the global warming potential of the same amount of carbon dioxide) over a period of fifty years would be enough to raise the temperature of the Earth by around three degrees centigrade[xxxiv], causing tight, intense feedback loops rapidly sending the planet into a climatic freefall.

This, you will appreciate, is not something that should be happening.

Some authors, largely those keen on the potential for mineral exploitation and the opening up of shipping routes, are reporting the potential changes as positive; one even goes so far as to say, “the warming of the globe’s climate could possibly lead to a more productive and positive natural environment than we have today.”[xxxv] I am guessing that most people with a semblance of concern for life on this planet would choke on these words: optimism is fine, providing there is something to be optimistic about – enjoying the fruits of global climate change while mass extinction takes place is little short of murderous.

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