Notes on “Six Degrees: Our Future on a Hotter Planet” (M. Lynas)

Lynas, Mark – Six Degrees: Our Future on a Hotter Planet (2007) PDF
Category: global warming, collapse; Rating: 5/5
Summary: Six Steps to Hell (Mark Lynas) 2007; Six Degrees Review (Real Climate) 2007; What will Climate Change do to our Planet? (Times) 2007

No-one disputes the denier argument that greenhouse gases are essential for life on Earth. But there is such an concept as too much of a good thing. It is ostrich-like to deny that our CO2 emissions, proceeding at rates unprecedented in geological history, will not soon lead to substantial global warming – current atmospheric CO2 levels were last seen during the Pliocene, when average global temperatures were almost 3C hotter. And it is Pollyannish in the extreme to maintain that the effects on human societies will be anything other than deleterious. In this book, Mark Lynas shows us why.

As I warned in my first proper Notes post – on Tainter’s The Collapse of Complex Societies – since I am doing this mostly for myself as part of my research into my book on “future history”, I cannot guarantee this will be interesting.

Introduction

Basing his work on the IPCC’s projections of 1.4-5.8C of warming for the 21st century, Lynas reviews the existing scientific literature as to the effects each degree of global temperature rise will have on our biosphere. To appreciate the scale of the upper range of these projections, consider that global temperatures were around 6C lower during the depths of the last Ice Age – when the North Sea was dry land, dessication affected even the tropics and massive ice sheets descended into central Europe, transforming it into a polar desert blasted by ice dust-laden winds.

In contrast to the conservative IPCC’s conception of climate change as gradual, he shows that there exist numerous positive feedbacks that will reinforce and accelerate global warming after the world warms by 2C – acidifying oceans will cease functioning as carbon sinks; the melting of polar ice will reduce the Earth’s albedo, making it more heat-absorptive; dying vegetation, including a possible Amazonian conflagration, will transform the world’s biomass from a carbon sink to a carbon source; melting Siberian permafrost will release previously trapped methane into the atmosphere, a greenhouse gas twenty times as powerful as CO2. Furthermore, anthropogenic global warming is occuring at rates unmatched in geological history as industrial civilization belches out carbon sequestered over tens of millions of years in decades, even as much of the world’s traditional balancing mechanisms – forests, biodiversity, mangroves, etc – have come under sustained human assault. Nor does it help that both palaeoclimate reconstructions and new models taking into account the “dimming” effect of human aerosol emissions indicate that the climate’s sensitivity to CO2 levels is as much as twice higher than previously thought. All this sets the stage for a massive extinction event by the time temperatures rise by 6C, as the world’s oceans turn anoxic, seabed methane hydrates are released and lethal hydrogen sulphide bubbles into the atmosphere from the dead seas, even destroying the ozone layer in the process.

Lynas decided to write the book on viewing the inundation of New Orleans, which he sees as a portal into the future – in which the rule of law is replaced by the rule of the gun, masses of climate refugees appear even in the world’s richest nations and industrial civilization fights its last wars for fuel and water with guns, grenades and nuclear weapons. Now for the degree by degree account.

One Degree

Though the Great Plains are one of the world’s great agricultural breadbaskets, a desert slumbers underneath. Increased dessication and pummeling storms will erode away the thin topsoil, recreating the Dust Bowl on a giant scale and re-awakening the sand dunes. More irrigation will only postpone the inevitable. There will be large-scale migration to the wetter Mid-West and Great Lakes regions. AK: actually called the Great American Desert during the 19th century!, and is now dependent on depleting Ogallala Aquifer.

Higher rainfall, glacial melt and strengthening Siberian rivers may interrupt the Gulf Stream (part of the Atlantic Meridional Overturning Circulation system), drying western Europe and cooling it by as much as 2C – recreating the conditions of the Little Ice Age during the worst winters. However, most models predict this will be a slow death. AK: If not, expect increased European dependency on Russian gas during the 2010’s and 2020’s.

In Africa, Kilimanjaro will lose its remaining ice by 2020 – causing wildfires, fish stock declines and problems with hydroelectricity production. Based on palaeoclimate, in the long-term there will be a greening of the Sahara (into a savanna) and an enlarged Lake Chad…however, models say that there will only be a short interlude of heavier rains in the Sahel and on the West African coast, followed by even fiercer drought.

Coral reefs around the world will be increasingly bleached and taken over by seaweed; polar bears are pushed off the top of the world and creatures like pikas are shoved off the planet, accelerating the Anthropocene Mass Extinction event. Hurricanes will become stronger and more ubiquitous, spreading to the South Atlantic. More rockfalls in the Alps. Increased incidence of drought in the Amazon, pushing it to the brink. Atolls become doomed worlds, fated to submerge amidst the rising waves.

Two Degrees

China will face floods in the south and drought in the north – amplified by depleting fossil aquifers and burgeoning industrial demand for water. It is hoped that the resulting lowered crop yields, continental dust-storms and water stress will be mitigated through the construction of a vast megaproject to bring excess water from the Yangtze to the parched north.

The oceans will become too acidic to support calcerous life, further depleting the world’s fishery stocks and corals. The demise of plankton ecosystems will diminish the ocean’s role as a sink absorbing around half of the world’s CO2 emissions.

Crops losses, water shortages (for irrigation, hydroelectricity), grounded barge traffic and melting mountain glaciers afflict Europe as it moves to a North African climate, in which the summer heatwave of 2003 becomes the new norm. Mediterranean Europe becomes much hotter and drier, reversing current migration flows to the north. Drought and heat stress will transform its vegetation from a carbon sink to a carbon source.

Arctic warming unleashes the melting of the Greenland icecap, as meltwater forms lakes and bores icy sink-holes called moulins onto the bedrock beneath the ice sheet, lubricating its base and accelerating glacier flow. Glaciers begin to retreat, thin and accelerate at exponential rates – much of Greenland will be gone by the end of the century, raising global sea levels by up to 7m. AK: the effects will initially be particularly severe in north-east North America.

The Arctic meltdown intensifies, as lakes drain away, permafrost vanishes and infrastructure finds itself built on quicksand. A triple whammy feedback effect kicks in – earlier snowmelt (part of which is replaced by rain) causes more summer heat to go into the earth; steep, dark-colored shrubs and boreal forests encroach on once-white tundra; and melting Arctic ice is replaced by dark ocean water, raising local temperatures because of the vastly lowered albedo and making it difficult for next year’s ice to re-form. Propelled into oblivion by the ice-albedo effect, the Arctic will soon be ice-free throughout the summer. This opens up global shipping routes and huge new hydrocarbon reserves to exploitation, ushering in a geopolitical Great Game in the High North.

Agricultural decline in India of 8% as crop yields fall in increasingly drought-stricken north, though West Bengal sees improvements; experiences refugee influxes from Bangladesh as it is overwhelmed by a stronger monsoon. The glaciers supplying Peru’s desert areas with water, including the capital Lima, will dry up – leaving it dependent on unreliable highland rainfall. Though temporary solutions like piped mountain water or desalination plants will be tried, in the end these settlements could be abandoned in favor of mountain villages, ushering in subsistence crises and upheavals. In California, smaller snowpacks (since more water falls as rain) means less water and earlier run-off in flooding will test its intricate hydraulic system to the limit – not helped by its burgeoning population and increased incidence of severe drought.

In the warming world, US food production holds steady but moves from the Great Plains and the West, to the north and Mid-West. Yields increase in western Russia and Scandinavia; overall Europe too remains steady, with a northward shift. There is great potential in Canada and Russia, but it will be difficult to develop rapidly. In South and Central America, the staple maize will decline everywhere except in Chile and Ecuador; much of Africa will decline, particularly its subtropical belt – though rainier Congo, and mountainous parts of Lesotho and Ethiopia, will benefit. In general, the countries that contributed to GW least are also the worst off – though mountainous and equatorial regions hold the line, yields decline in the drier subtropics, inducing structural famine in the most destitute nations.

The ongoing sixth great extinction event will be turbo-charged by climate change, which too many species are too slow, too specialized or too already-damaged to escape. It is moving north at 30km per year – much too fast for butterflies (2km), forests (1km) or beetles (0.2km) [AK: and bees?] to adapt to. More than a third of today’s species will die off, ushering in a hot, silent summer. In the coming Age of Loneliness, humans will have to try to replace nature’s prior services on an increasingly artificial and fragile world. AK: through hydroponics, species transfers, systems studies, fish farms, bioengineering, geoengineering, etc.

Three Degrees

Eventually, conditions will resemble those of the Pliocene, when stunted shrubs grew in the Transantarctic Mountains, conifers populated northern Greenland and East Africa was covered in lush forests. But as for the transition…

Even as the tropics and mid-latitudes drown in floods, the subtropics bake to death – including much of sub-Saharan Africa, where increased evaporation due to heat and much stronger winds erode away the topsoil to reveal the sand dunes of the greater Kalahari desert. Botswana is covered in dunes in its entirety, as is much of Zambia, Angola, Namibia, western Zimbabwe and northern South Africa – making human habitation impossible. Meanwhile, East Africa gets more humid – increased rainfall in Somalia, Kenya, Tanzania, Mozambique, etc, results in more flooding and malarial infestation, further compounding Africa’s development crisis.

Much of the interior of and southern Australia becomes inhospitable because of an unholy trinity of fire, heat and drought – leading to general agricultural collapse, drying rivers, salination and gigantic conflagrations (pyro-cumulonimbus, black hail, tornadoes and huge smoke stacks).

There may appear a permanent El Niño, in which Peru and California suffer from more storms and floods; the Amazon desiccates; drought afflicts southern and northern Africa, India, Indonesia, and Australia; the US has milder winters and calmer Atlantic hurricanes; and Europe experiences drier winters.

Increasing dessication leads to the collapse of the Amazon rainforest. Home to half of global diversity, 10% of Earth’s net primary productivity and its main river containing 20% of all water discharged into the world’s oceans, the Amazon is already under siege from cattle ranching, soya plantations, roads and illegal logging. As it is increasingly afflicted by drought, its soils shift from being carbon sinks to carbon sources – further exacerbating warming. Fires spread, accelerating the downfall – its slow regeneration allows more sunlight to penetrate the forest canopy and further dry out the forest floor, while rainfall is suppressed by the resulting months-long clouds of smoke. The collapse starts from the north-east and spreads, culminating in a massive conflagration as walls of flame march across the remaining forest – covering the whole region in choking smog, raining down gray drizzles of ash and blotting out the Sun with a leaden pall. No vegetation survives except bits of grassland and savanna at the edges. The world’s former hydrological engine turns into a sweltering desert of Saharan temperatures, fierce sandstorms, and meandering, muddied gorges.

Central America is already suffering from overpopulation, destruction of forest cover and erosion, like the Mayans of old; global warming will lead to severe droughts, subsistence crisis and socio-political collapse, resulting in mass emigration that will again leave behind ghost towns and monuments to a lost culture. Although at first it may get weaker due to the Asian Brown Cloud, the Indian monsoon will then become stronger – leading to more variability (increasing catastrophic flooding AND droughts) and exacerbation of current humidity differentials (it will be wetter on the Indian west coast and north-east, Bangladesh and the Bay of Bengal; drier in north India and south Pakistan).

Since the Indus Valley is essentially desert, with no rain coming in from either the Punjabi plains or the lawless mountains of Balochistan, the river is almost entirely reliant on Himalayan ice-water melt. As the glaciers dissipate, flows will at first swell, but will later crash for months at a time during the dry season. This will devastate the canal-watered Punjabi breadbasket, ushering in a subsistence crisis and translating into a wider crisis in the Pakistani economy due to the collapse of cash crops like rice and sugar. (There will also be problems in Western China and India, which are also heavily reliant on Himalayan melt – India may experience blackouts due to failing hydro-power production in summer, leading it to hold back water in reservoirs and thus stoke conflict with Pakistan). Pakistan devolves into a failed state in nuclearized anarchy and will possibly instigate a last-ditch war with India, as the shimmering white of old glaciers gives way to bare rubble and sun-baked soil.

Due to greater winter rainfall and quicker snowmelt, incidence of drought will increase on the American west coast – putting great strain on the plumbing system of the Colorado River and devastating agriculture in California, Washington and even Alberta.

From Houston to Shanghai, coastal cities will experience far more powerful storms due to hotter seas. New York City will become much more vulnerable to catastrophic flooding, as storm surges strengthen in response to more powerful hurricanes and nor’easters, which together with sea level rise will make parts of it economically unviable – in response, the city may construct billion-dollar flood barriers to shield itself. Stronger storms in the North Sea put London and Netherlands at increasing risk due to storm surges. Droughts and floods both increase, as Alpine glacier melting causes similar effects on Europe similar to that of the aforementioned Colorado on the western US – even as parts of the Mediterranean rim start desertifying.

Rainfall shifts north to Canada and Alaska, further exacerbating drying in western North America. Greenland is in rapid meltdown, as it loses water to emerging glacial rivers and new, blue lakes trapped between gravelly moraine and the retreating icecap. Iceland loses its ice even faster. Though growing seasons in the High North increase, their thin, rocky and acidic soils are unlikely to compensate for the desiccating breadbaskets.

Since grain yields decline at temperatures higher than 30C, agriculture in the arid sub-tropics becomes increasingly untenable – in central America, south India, Indonesia and (rain-fed) southern and northern Africa. Crop yields begin to slide in the tropics as it becomes simply too hot. In North America, agriculture moves north to the Mid-West and east Canada, even as the West and South-West is afflicted by drought, heavy rainstorms and new pests. There will be a net global food deficit after a 2.5C rise – even the mid-latitudes suffer due to extreme floods and droughts, while structural famine grips the subtropics and creates hundreds of millions of climate refugees. The rich world turns to isolation or fascism, while eco-extremist ideologies take root amongst the uprooted nomad masses.

Four Degrees

Since much of the base of the West Antarctic ice sheet is grounded below sea level, warmer oceans stand to erode its edges and call its whole stability into question – especially as most of the center of the great ice mass is even deeper below sea level than the edges, penetrating sea water could lift the icecap off its seabed foundations. Although it is shielded by the massive Ross and Ronne ice shelves, if they were to disintegrate the West Antarctic would get uncorked – resulting in much faster glacial outflow and adding 5m to global sea levels within decades. (Already three shelves have disintegrated – the Wordie, Larsen A and Larsen B). Though the East Antarctic cap is shielded by the Transantarctic Mountains, is too is anchored beneath sea level so it could collapse via the back door – eventually raising sea levels by a further 50m. Destabilization of both Antarctic ice caps and Greenland will result in unmanageably rapid inundation of the world’s urban commercial centers and low-lying farmland.

Entire nations like Bangladesh, Holland and Egypt will be put at risk; cities will become besieged fortresses under constant risk of catastrophic breakdown before the rising seas and gathering storms. Agriculture will need to move onto higher, more marginal lands. As the world’s coastlines retreat, the resulting economic shocks will destabilize society and break the insurance and credit systems – leaving fewer resources to support the hundreds of millions of newly-displaced people, as the world is wracked by the Scylla of inland drought and the Charybdis of coastal inundation.

Industrializing China is already in deep environmental decline – most lakes are polluted by agricultural or industrial runoff, the Yellow River is depleted and toxic, and it suffers from rapid topsoil loss, acid rain, dirty air in major cities and massive coastal pollution (sewage, farm pesticides, oil spills cause 90 poisonous red times year). China’s continuing industrialization is putting unprecedented and unbearable stresses on the world’s energy resources and ecological services. At a temperature rise of more than 3C, its production of food staples crashes by up to 40% – even excluding the impact of rapidly falling groundwater tables on irrigation systems. Though it could try to use its manufacturing-exports clout to close the gap on world food markets, by now agriculture will be crashing throughout the world’s mid-latitudinal breadbaskets, as the subtropics get too dry and the tropics too hot – the Great Plains, the western US, the Pacific coast of S. America, southern Africa, the western Indian subcontinent and Australia all see major declines. Droughts will prevail in SW North America, Central America, the Mediterranean, S. Africa and Australia – SE Asia during the winter, and the Amazon, Siberia and West Africa during the summer. Although(marginal) sub-polar lands will be opened up in Russia and Canada, and yields may rise due to new bio-engineered drought-resistant crops and the fertilization effects of increased CO2 levels, this will not close the gap – the situation will become ever more precaurious, for “with major global breadbaskets dusty and abandoned, rising demand will be chasing rapidly diminishing supply”.

Civilizational collapse will sweep the inter-connected globe like a neutron bomb, “overtaking a planet whose natural defense mechanisms have already been severely damaged by human activity” (fertile soils stripped of trees and grasses and appropriated for farmland, oceans sucked dry by gigantic factory ships, etc), endangering previously free ecological services (cloud-forming plankton, the Amazonian hydrological engine, the ocean’s carbon sequestration, etc) – at the same time as humans turned the heat on. Greenland is in full meltdown, the West Antarctic is collapsing and Atlantic circulation is shutting down (by now too late to significantly cool down Western Europe). The long days of summer reduce “forests to tinder and cities to boiling morgues”, even as the world’s “weather will go increasingly haywire, with wilder storms mobilizing undreamt-of ferocity as they strike ever larger areas”.

New deserts are spreading in Europe, which now suffers from perennial summer droughts and heatwaves in the Mediterannean, with ripple effects felt as far away as Ukraine and southern Russia. During summer, London and Switzerland see temperatures now associated with Marrakech. Temperatures soar throughout continental interiors, hitting hydroelectricity production and lead to imminent grid collapse [AK. Not helped by the fact the Earth's magnetic field is weakening]. The Caspian drops by 10m. Snow becomes an oddity even in eastern Europe, desiccating the summer North European Plain. On Lifeboat UK, drought in the south-east is punctuated by more severe floods on the low river plains; there are more severe but fewer storms in the north-west and Scotland. The flight to the north intensifies and extreme political movements gain ground as socio-political collapse looms near.

I met a traveller from an antique land
Who said: Two vast and trunkless legs of stone
Stand in the desert. Near them on the sand,
Half sunk, a shatter’d visage lies, whose frown
And wrinkled lip and sneer of cold command
Tell that its sculptor well those passions read
Which yet survive, stamp’d on these lifeless things,
The hand that mock’d them and the heart that fed.
And on the pedestal these words appear:
“My name is Ozymandias, king of kings:
Look on my works, ye Mighty, and despair!”
Nothing beside remains. Round the decay
Of that colossal wreck, boundless and bare,
The lone and level sands stretch far away.

Alpine glaciers melt, in the process unleashing avalanches of suffocating wet snow and flash floods. Europe’s water tower dries up. Eventually, drought turns the Alps from verdant green and snowy white to a moonscape of baked-earth browns, with just a few hardy shrubs and grasses clinging on to life near the tree-line – just like the Atlas Mountains.

In a warmer world, rainfall becomes more convective – characterized by small, violent cloudbursts like thunderstorms with longer dry periods in between (as opposed to the gentler rain associated with the passage of frontal depressions). This is particularly noticeable in central and northern Europe, SE England and Korea – though overall rainfall may increase, increased temperatures also drive up evaporation, resulting in a much drier land surface. Even where cultivable soils remain, not succumbing to desert, these heavy cloudbursts accelerate erosion and convert once fertile plains into gullied badlands capable of supporting only marginal grazing.

By now, the Arctic is long ice-free and the sounthern permafrost boundary shifts hundreds of kilometers north – causing extensive infrastructure damage over large areas of Siberia, Alaska and Canada. Lakes drain and rivers alter course as 30% more fresh water drains into the Arctic Ocean from extra rainfall and thawing ground. In the mossy tundra, trees and bogs appear. This is going to release vast amounts of Siberian methane – 1) where lakes and marshes drain and dry out, bacteria breaks down nutrients to form CO2, 2) anaerobic bacteria moves into still wet areas to perform oxidising decomposition, producing methane – a much more potent greenhouse gas, and 3) in some areas carbon dissolves into water directly, and is later released as CO2 from lakes, rivers and the Arctic ocean. This is an extremely dangerous feedback that will catapult the world into…

Five Degrees

Resulting in a new world coming into being – one with a permanently ice-free Arctic, acidic oceans, collapsed ecosystems, burnt out rainforests, intense heatwaves and hurricanes, rapid inundation of coastal areas, outward spread of the world’s deserts and a climate increasingly bifurcated between wet and dry. Higher evaporation desertifies already semi-arid regions. Two globe-girdling belts of perennial drought appear – encompassing the central Americas, southern half of Europe, the Sahel and Ethipia, southern India, Indochina, Korea, Japan and the western Pacific in the north; southern Chile and Argentina, eastern Africa, Madagascar and Australia in the south. A more intense monsoon increases the flows of the major Indian and Chinese rivers; rivers in the Far North also become much more powerful. In tandem with depleting fossil aquifers, desiccation of continental interiors and disappearing snow and glacier melt, global warming will force biblical-sized migrations to the thin, poor, rocky and acidic soils of the Far North where the displaced will strive to eke out a subsistence existence. If the northern powers let them in, of course…

Surrounded by agricultural and urban deserts, the world’s remaining oases of biodiversity – its denizens unable to flee, being too slow, too specialized and too isolated – will be rapidly submerged under real deserts.

Methane hydrates, an icelike combination of methane and water, are only stable when very cold or under high pressure. If destabilized by submarine slides of deep ocean warming, they can explosively sublime, releasing epic amounts of methane into the atmosphere. This will further accelerates global warming, leading to ever more acidic oceans, desertification, intense thunderstorms, topsoil washoff, more extreme downpours and lush redwood forests around the high Arctic (creating water vapor, insulating itself during the long polar darkness) – as during the Paleocene-Eocene Thermal Maximum (PETM) 56mn years ago. Because of its shallow depth and subjection to the most extreme warming, the Arctic Ocean is going to be the locus of methane hydrate releases – which will in turn destabilize sediment downslope of continental shelves in shallower seas, resulted in sumarine slides, tsunamis and further methane hydrate releases.

The resurgent monsoons will take time to work themselves up, thus postponing any relief for desiccated northern China or Pakistan. As the tropics become too hot for crops and the subtropics dry up, the belts of habitality contract towards the poles, both on land and on sea – ushering in a new era of enforced localism, in which globalization totally collapses. New refuges include: the High North, northern Europe, the British Isles, rainy highland areas of Africa, Tasmania, New Zealand, Patagonia and Tierra del Fuego, and newly-defrosted parts of Greenland and Antarctica – however, this is not enough and there will be wars for Lebensraum. Rising sea levels turn many coastal cities into wave-battered ghost towns and inundations of low-lying, fertile plains like the Nile, Yangtze and Meghna deltas further decimates agriculture. Life near the seas is precaurious due to heavy storms and tsunamis. The world descends into anarchic violence, ushering in a global Malthusian crisis as the global carrying capacity plummets – and is further reduced by masses of desperate foragers. During the “cull” / dieoff, there are new holocausts, wars are fought with guns, grenades and nuclear weapons, and the world population is reduced by the billions.

Six Degees

The Creteceous world saw a Mediterranean climate at the poles and tropical ones at high latitudes; extremely powerful storms, leaving behind tempestites and even hummocks on the ocean floor, were driven by extremely hot oceans (reaching 42C in the tropical Atlantic!, 32C in the subpolar Atlantic and nearly 20C at the North Pole). The Arctic was humid and temperate, supporting lush forests (there may have been evergreens at the South Pole); the mid-latitudes were warm and humid, but subject to intense droughts and burning; below them there was an arid belt; the equatorial tropics saw the heaviest rainfall and severest storms, but little biodiversity. Though warm and sticky, it may have been quite nice…but the current rate of change is unprecedented in geological history and our ecosystems have no hopes of adapting in time.

Instead, the world may repeat the end-Permian extinction event. The warm seas will expand, forming numerous shallow seas. They will also power hypercanes of incredible ferocity that will circle the globe repeatedly. Deserts spread as far north as the Arctic Circle. Yet the real “kill mechanism” will lurk in the deeps…

Methane releases from collapsed methane hydrates will dissolve throughout the water column over time, each successive layer of water gradually reaching saturation point and priming the explosive. Now all it needs is a detonator – a small disturbance on the seafloor. This drives a parcel methane-gas-saturated water, which releases a cascading stream of bubbles as the dissolved gas fizzzes out because of the falling hydrostatic pressure. This makes the parcel of water still more buoyant, accelerating its rise through the water column. As the water surge up, it drags the surrounding water up with it, spreading the process across the whole water body. At the sea surface, water is ejected hundreds of meters into the air as the released gas blasts into the atmosphere. This may generate a supersonic shockwave that ignites the exponentially growing methane blanket, pushing out an explosive front at speeds of 2km / sec and vaporising everything it is paths. This fireball of doom could release more energy than contained in the world’s nuclear stockpiles by orders of magnitude, resulting in nuclear winter followed by renewed warming.

And that is not all. The global ocean convection system will shut down, creating an “ocean anoxic event” that kills all oxygen-breathing marine life, building up lethal hydrogen sulphide in the ocean depths. Starting from partly enclosed basins like the Mediterranean or the Gulf of Mexico, or the already anoxic Black Sea, it too will be released into the atmosphere. Lethal in minute concentrations, the only warming will be the smell of rotten eggs before the olfactory nerve becomes paralyzed. It will be a silent killer, making its way from the coasts to the continental interior. Furthermore, it will break down what remains of the ozone layer – exposing any remaining survivors to carcinogenic UV rays.

Though humans are cleverer and more adaptable than the creatures of the end-Permiant – they can stockpile essentials, filter out poisonous gases and eat a wide range of foods. That said, human survival as a species is far from assured if this unholy trinity of spreading methane fireballs, hydrogen sulphide poisoning and UV radition comes to pass on an Earth rapidly transitioning into Mad Max in Death Valley surrounded by Waterworld.

Choosing Our Future

There are two big unknowns: 1) future emissions and 2) climate sensitivity.

Warming of at least 1C is already locked in whatever we do, making the Great Plains, the Great Barrier Reef and numerous species “living dead” (yet based on palaeoclimate, perhaps a Pliocene-like state with its 3C rise and 25m higher sea levels is inevitable). Though most models give a rise of 3C for a doubling of pre-industrial CO2 levels (from 280ppm), some project warming of as high as 11C (!) because of prior neglect of the role of sulphur aerosols in producing “global dimming” (which suppressed early signals about climate sensitivity to rapidly increasing CO2 levels). Since aerosols are scrubbed out of the atmosphere in a matter of days (in contrast to CO2 which lingers for centuries), this means that temperatures will from now follow the high end of the IPCC’s predictions of 5.8C, or even higher. AK: the fourth IPCC report actually raised the maximum to 6.4C.

Therefore Lynas says temperatures have to be stabilized below 2C, because from then numerous catastrophic feedbacks kick in – the burning of the Amazon (+1.5C) –> accelerated released of CO2 and methane from Siberian bogs –> ocean methane hydrate release –> mass extinction apocalypse. all this is ASSUMING A LOW CLIMATE SENSITIVITY, there is a 25% of overshoot at 400ppm (we’re currently at around 385ppm), and more than 85% chance at 550ppm – the only hope of salvation is to achieve peak CO2 emissions by 2015, and rapidly reduce them 90% by 2050.

He suggests a global contraction and convergence plan, but acknowledges it will be difficult in practice because of industrial civilization’s dependence on cheap fossil fuel even for its food. He refuses to engage in platitudes about renewables and notes that a shift from coal to biomass will result in renewed deforestation, as in today’s rich countries a century ago. Instead, he stresses the need for a values change towards post-materialism – now constrained by social pressures to live a high-energy lifestyle, indulge in blame games, denial, manufacture “needs”, faith in the technological fix and utter denial of resource limitations (e.g. the GDP farce).

He cites the idea of knocking in carbon “wedges” (seven will reduce 2055 emissions to those of today – i.e. still far too little, too late). Ideas include: raising vehicle fleet fuel efficiency from 30mpg to 60mpg; halving the average distance traveled by each car [AK: hard since vehicle fleet is rapidly expanding in emerging markets]; more efficient buildings; more efficient electricity generation; quadrupling of gas-fueled power stations to replace coal [AK: gas peak probable by 2020's!]; 700new 1GW nuclear power plants [AK: great idea!]; “carbon capture and storage” applied to 800 similar-sized coal plants [AK: CC is greenwash] – i.e., none of these ideas are currently feasible except the nuclear option. Furthermore, Lynas adds some of his own wedges: 2mn 1MW wind turbines (50x increase from today!); solar PVC increase by 700X from today!; 4mn 1MW turbines in place of coal; build a hydrogen transport system.

Lynas does not have the solutions

As for the solutions, I mostly disagree with Lynas. He opposes nuclear power – I think it is the one energy source that has a hope of saving industrial civilization, which is probably worth a somewhat elevated probability of nuclear proliferation. He emphasizes wind power, which can never be a major source of power because of its huge output fluctuations, low energy intensity and low EROEI). He proposes carrying through all these societal changed through market mechanisms, such as carrying through “carbon rationing” by using it as a parallel virtual currency that can be exchanged for real money – a monumentally stupid idea, since this is extremely regressive, will breed resentment against the rich and preclude the formation of new values.

As I said in my last post on AGW, the only hope of salvation – and without gambling on geo-engineering, it’s already a very small one – is to embark on the road to Green Communism.

Related posts:

1. Notes on “The Last Generation” (F. Pearce)
2. Notes on “The Olduvai Theory” (R. Duncan)
3. SSR #8: On Future War
4. The Dilemmas of Global Dimming
5. Top 10 AGW Denial Myths