Overloading Emoh Ruo: the rise and rise of hydrocarbon civilisation
From Griffith REVIEW Edition 12: Hot Air
© Copyright Griffith University & the author.
Written by Murray Sayle (dec.)
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Murray Sayle's biography and other articles by this writer
No one discovered global warming, although it has been going on for most of the past 12,000 years. The suspicion that human activity is altering the world's climate forced itself in slow stages on disbelieving scientists, as it is now reaching a wider but only half-persuaded public. The science is complex, the factual forecasts tentative at best. One simple truth is, however, now established beyond any doubt, one of those rare insights that will change the way we think as long as our species lasts. We have only one single human household, the much-abused planet under our feet. We are hopeless at managing it, a dysfunctional family riven by jealousy, selfishness and self-imposed ignorance. We show no real sign of changing our ways. If we go on like this, the outlook we refuse to face up to is grim.
Cape Grim Baseline Air Pollution Station is a modest collection of prefab huts atop a blackened tooth of sandstone that juts from the north-west corner of Tasmania into the Southern Ocean at latitude forty degrees forty-one minutes south. This is uncomfortably inside the Roaring Forties, the winds that blow clear around the globe with only a short passage over the distant wilds of Patagonia, raising swells that break with few pauses on two saw-toothed islets at Grim's foot, ninety-four metres below. Above the huts, which house a rotating team of nine scientists and their instruments, soars a slender steel tower, with air intakes sampling the winds at 104 metres and 164 metres above the sea.
Grim was given its peculiarly prophetic name by Matthew Flinders, RN, then aged twenty-four, who set out from Sydney in the southern summer of 1798 with surgeon George Bass, twenty-six, in the seventeen-ton sloop Norfolk to test whether Van Diemen's Land, as it was then known, was part of New South Wales or, as many suspected, an island in its own right. The two youthful shipmates sailed (and named) Bass Strait from east to west and, threading their way through the Hunter Isles at the strait's western mouth, kept careful watch for the unknown coast to bear away to the south-east, conclusive proof of their island thesis. Sure enough it did. Introducing his Voyage to Terra Australis (which, incidentally, gave this country its name and has caused so much grief to Austrian postmasters), Flinders wrote: "The north-west cape of Van Diemen's Land, or island, as it might now be termed, is a steep black head which, from its appearance, I call Cape Grim."
THE WINDY CAPE STEMMED THE ROARING FORTIES IN LONELY ISOLATION until 1976, a year in which, with the Vietnam War ended and the Middle East unusually quiet, thoughts turned to meteorology, the science of weather, an area in which even the most self-centred of nations can see advantages in exchanging information. While military men keep a covert eye on the world climate, they like to show themselves co-operative in a good cause and, as children everywhere have discovered, what sounds more seductive than "You show me yours and I'll show you mine"?
It was a time of bizarre weather events. In the early 1970s, India's life-giving monsoon failed and there were poor harvests in Africa and the then Soviet Union. Cities worldwide were getting grimier, with black-rimmed collars and high-rent urban vistas shrouded in smog – not the Great 1953 Killer Smog, caused by burning coal in a million grates, which paralysed London for three days and killed thousands, but something more complex and mysterious. In 1975, the World Meteorological Organisation, an offshoot of the United Nations, called for member states to finance a worldwide chain of twenty-two reporting stations in out-of-the way places to investigate these odd events. No one, for once, vetoed the innocent-sounding proposal. The decision gave Cape Grim a new global significance.
There was a precedent, of sorts. In 1957, another quiet year internationally, the United Nations proclaimed an International Geophysical Year, partly inspired by the launch of the first man-made satellite, Sputnik. That year, an American scientist-hero, Charles Keeling, set up an air-sampling station atop Moana Loa, a 4,169-metre peak in the Hawaiian Islands, surrounded by thousands of kilometres of pristine ocean air. Keeling nursed a suspicion that carbon dioxide, CO2 , was somehow changing the climate. A genius at scrounging funds, Keeling almost ran out of money several times, but kept on refining his methods and measuring the air.
Sure enough, his findings showed a steady, steplike climb of airborne CO2 between 1957 and 1975, but the quantities were still minute. Most of us know that the air we breathe through our air-conditioners is roughly four-fifths nitrogen and its derivatives, now rising; a fifth is oxygen, falling; and less than one per cent other gases and odds and ends, some nasty. Keeling's air samples showed an increase of CO2 from 315 to 330 parts per million of air in almost twenty years. But Moana Loa is an active volcano, volcanoes spew CO2 , among other gases, and maybe this was skewing Keeling's findings.
All that fuss, his critics scoffed, about a wisp of harmless gas. It is true that the danger, if there is one, is far from obvious. We all breathe out about a kilo of CO2 every day of our lives. It makes the bubbles in champagne, the froth on beer. It forms the swirling clouds of vapour through which ageing rock stars make their entries. Shopkeepers still pop a pellet or two of dry ice, the solid form of CO2 , into parcels of frozen food, and children find they bubble briskly underwater. Could this fun gas really end life as we know it? Keeling visited the Antarctic in 1957, not exactly crowded with human activity, and found that CO2 levels in the frosty air climbed in a single season. The pattern he detected at Moana Loa was repeated in the pristine Antarctic.
AUSTRALIAN WEATHER SCIENTISTS HAD LONG SEEN THE POSSIBILITIES of Flinders' sinister Cape Grim for a "baseline" station. It was an ideal spot to measure the atmosphere's minimum level of CO2 and other suspect gases, before human or natural activity, nearby or distant, could add to it. A quirk of history had kept Grim all but untouched by human boots. In 1976, the Cape was still part of a grant of 22,000 hectares (220 square kilometres) made in 1825 to the London-based Van Diemen's Land Company (VDLC), intended to exploit the raising of fine wool in the then remote Tasmanian north-west, and thus called Woolnorth. The station still flourishes and still belongs to the VDLC, the only surviving Royal Charter Company, which also has holdings in New Zealand. The last volcanic activity in the region ended some twelve million years ago.
Woolnorth, originally staffed by indentured labourers from England with their wives and children, and ticket-of-leave convicts, got off to a brutal start, with records of "depredations" by the local natives – a sad glimpse of Tasmanian Aborigines, soon to disappear from human history – and of unauthorised, violent reprisals by the company's well-armed "servants". Woolnorth only began to prosper in the 1850s when gold was found in nearby Victoria and the VDLC developed Woolnorth as a supplier of beef, mutton and potatoes for the diggings; it has continue to prosper as a supplier of fine wool.
Bare and roadless, Cape Grim was unsuited for these profitable lines and the Australian Bureau of Meteorology (BOM) and the Commonwealth Scientific and Industrial Research Organisation (CSIRO) acquired title to the tip of the cape with a buffer strip between it and Woolnorth in 1957. It was to become one of the World Meteorological Organisation's baseline monitoring stations. The first air samples were collected in April 1976, the brief being to analyse the four so-called greenhouse gases: carbon dioxide, methane, nitrous oxide and sulphate aerosols, which are co-emitted with airborne soot.
Carbon dioxide lingers for 150 years or more in the atmosphere and so has attracted the most nervous column inches. Methane, otherwise known as swamp gas, has more drastic affects on the climate but disperses after a decade or so. Nitrous oxide is a compound of oxygen and nitrogen, the main ingredients of air, and eventually breaks down. Sulphate aerosols, which are not gases, are better known to us as the smog that dims our cities. All are natural products and are present in all air samples. Methane bubbles up from vegetation decaying in swamps, or in the long swamp-like intestines of grass-eating animals or, in layperson's language, from farting cows. Nitrous oxide is produced when lightning heats air. Some sulphate aerosols come from volcanoes, some from bushfires.
Sure enough, ice cores record the four substances fluctuating in no discernible pattern over many millennia. Then, beginning about the end of the eighteenth century, the four begin what looks like a concerted climb. In the documents issued by the fifth session of the Intergovernmental Panel on Climate Change (IPCC) in Nairobi in April 2001 – the smoking gun of global warming, if there is one – the concentration of the four substances in the cores faithfully track each other until, as Grim and the other baseline stations take over after 1976, they approach the vertical. No one has come up with a better explanation than the obvious: the graphs show the consequences of human activity, the oncoming industrial, fossil-fuel-fired revolution, the still incomplete triumph of our own beloved hydrocarbon civilisation.
The views from Cape Grim are awe-inspiring – to the north, Bass Strait, to the west, the empty ocean, and, curving away to the south-east, Valley Bay, which convinced Bass and Flinders that Van Dieman's Land was indeed an island. In the distance is the wind farm operated by Hydro Tasmania, whose thirty-seven giant rotors power the whole operation and feed surplus electricity into the Tasmanian grid. But no one lives at Grim on a permanent basis. The offices and living quarters of the scientists and technicians are sixty kilometres away, in the nearest town, Smithton (pop. 3,495), a cheerful place named, like much else in these parts, for a long-dead director of the VDLC. For its size, Smithton has every mod con, with two pubs, three supermarkets, two ATMs, a hospital and a swimming pool filled from the Duck River on which the town stands.
The analyses of the air samples collected at Grim are automatically sent by the web to Smithton, to the CSIRO in Melbourne, the Woods Hole Oceanographic Institute in Massachusetts, United States, and other interested parties. But Grim's remit is to study not simply the baseline of CO2 in the atmosphere, but some other so-called "greenhouse gases" as well: methane (CH4), nitrous oxide (N2O) and a group of human-made gases incorporating fluorine or chlorine that do not occur in nature and for which there is therefore a simple, if heroic, remedy – stop making them. Constant refinements in detecting these gases require frequent visits to Grim by the scientists and technicians, and occasional overnight stays.
Alas, the term "greenhouse gas" is a metaphor which, like many such, started off as a brave attempt to make a complex idea clear and wound up befogging understanding even more and opening the way to charges of deceit and even fraud. To make things worse, it omits the most potent "greenhouse gas" of all – H2O, plain, ordinary, tap, river or seawater in vapour form. The truth is, your common or garden greenhouse has no greenhouse gases. It works by letting sunshine through its clear, glass or plastic walls. Homonuclear, diatomic molecules – a mouthful meaning the simple, healthy gases like oxygen (O2) and nitrogen (N2) of air – do not absorb any energy from sunlight, which shines through on to the earth floor of the greenhouse, warming it and the air just above it. Warm air rises, and so the air in the greenhouse warms up, trapped by the clear walls. It is said that greenhouse operators in cold climates like the United Kingdom have been known to add CO2 as well, but this is rumoured to give their tomatoes a woody taste and so is best avoided. Our Earth has no walls and is not a giant greenhouse – any rising, warm air is dispersed by the winds and mixed by turbulence. The principle involved is different and the other so-called greenhouse gases have nothing to do with greenhouses, real or metaphorical; sulphate aerosols are not even a gas. Still, "greenhouse" is easier to remember than homonuclear or diatomic, so we are stuck with the term, and had best understand it.