The Best Australian Science Writing 2012 (21 page)

one of the toughest challenges for contemporary science: Practically none of the planetary cases studied can be either dismissed (by firmly ruling out a possible anthropogenic triggering of irregular dynamics) or settled (by providing relevant estimates for activation temperatures and reaction time scales) … it seems that we have to live with at least another decade of tantalizing ignorance concerning the most worrying potential impacts of global warming.

But the concluding paper observes that given the momentum and trajectory of warming, the climate system is close to entering, if not already within, the zone of ‘dangerous anthropogenic interference' (DAI). Scientific and policy literature refers to the need for ‘early', ‘urgent', ‘rapid' and ‘fast-action' mitigation to help avoid DAI and abrupt climate changes. It urges policymakers to look at a range of fast-action levers they might pull to avert a dangerous tipping point – among them cutting other greenhouse atmospheric agents such as hydrofluorocarbons and black carbon (soot, much of it from wood and fuel cooking stoves in the world's poorest kitchens), and through biosequestration (preserving forests and improving agriculture). It argues that such measures are necessary given ‘the serious and largely irreversible changes to large components of the Earth's climate system'.

For all this, on Sunday, 20 December 2009 all seems well enough in my privileged corner of the world – the leafy suburbs of middle Melbourne. It's too dry, too hot, the worst drought in over 100 years in southeast Australia dragging into its 13th – and, as it turns out, final – year. Nonetheless the economy is trading briskly in the comfortably chilled retail complex up the road. Plainly the recent devastation of global markets was rather more galvanising politically than the affliction of global warming. Investment in fixing that, and the subsequent recovery, has been astonishing. Not much more than a year earlier, the money markets were in freefall, consumer culture was in a critical condition, and the end of the world (as we knew it) indeed felt nigh. In that instance, public interest, panic and political energy all coalesced to save the day.

For a moment, in that tremulous time, another plane carried me to another reality, Mozambique. In the fractured concrete shell of a broken-down school outside Maputo, I happened on a large, vibrant gathering of peasant farmers and activists from all over the world, deliriously nursing the notion of the crisis over-hauling
markets and imposing a leaner, greener economic order – aspirations which must have read like heresy when I reported them home. They were unashamed subversives, right down to their faded Che Guevara T-shirts. A firebrand Brazilian revolutionary tap-danced, somewhat prematurely, on the graves of greedy bankers. ‘There is a hell for them too!' he beamed. He must be so disappointed.

In Maputo, the plummeting stock market didn't preoccupy discussion nearly so much as the wild shifts of the environmental indexes. Under a tree laden with unripe mangoes, a Bolivian woman in a bright shawl and a bowler hat told me about the vanishing glacier high above her farm, and about the unseasonal frosts which nipped without warning at her camomile crops. The agrarian world is full of such stories – staples failing where they once thrived, new crops thriving where they once failed, bananas and coffee plantations shifting up and down the altitudes of mountainsides. None of the rhythms are running to the seasonal schedules passed down from parents and grandparents. The same story is heard at any gathering of farmers, anywhere in the world. I have reported variations of it from Malawi to Congo to Papua New Guinea; from Afghanistan to the parched wheat belt of the Australian Wimmera.

There will be no farmers to talk to at the end of this flight. No indigenous community, other than the remnants of the population of whiskery, disoriented over-winterers finally stirring from the isolating slumber of the long Antarctic night. At the invitation of the Australian Antarctic Division (AAD), I am to spend the next few weeks observing and reporting field research out of Australia's Casey station. High summer, when the winter darkness lifts and the wind draws breath, is peak season for Antarctic science. Temperatures ease and researchers from all over the globe find their way down to the bottom of the world.

It's my second excursion to the Antarctic ice, and like last
time, I will fly down to Casey in a coveted seat aboard the Australian government's Antarctic Airbus – a chartered A319 which came into service only a couple of seasons back. The old hands of the south reckon the flight is too easy, not a patch on the experience of the long, lurching rite-of-passage voyage aboard an icebreaker. But whatever gets me there.

Preparations for working in such a remote location are painstaking. Camera gear and laptops have long since been shipped on ahead, together with survival bags stuffed with extreme-weather kit – glacier boots, layers of thermals and fleece, whiff-proof knickers spun from finest wool which the makers claim might be worn for weeks at a time, a bulky immersion suit worthy of an
Apollo
moon mission, goose-down jacket, and weatherproof overalls. A preliminary sweep of scientific interviews is complete, reference material collated. The division doctors, after intimate investigation, have again pronounced me sound of mind and body and fit to deploy, surprising several of my nearest and dearest.

The formidable list of training requirements is finally ticked off. I've set up tents, lit up stoves and put out fires. Endured three hours of intricate instruction on how to Lift Heavy Stuff, including uncooperative seals, though it's unlikely that I – unlike some of my hirsute training companions – shall have the pleasure. Fiddled with the VHF and learned the Alpha, Bravo, Charlies of radio etiquette. Struggled to stay conscious through the ubiquitous public service ‘Equity and Diversity' module (‘play nicely with the other kids'). Paid careful heed to instructions on how to avoid a) falling into a crevasse; b) falling over an ice cliff; c) frostbite. Almost drowned in a swimming pool rehearsing routines to escape a sinking aircraft – upside down
and
blindfolded. Spent too many nights since then methodically dreaming my way out of watery graves – exit, CHECK; harness, CHECK; obstacles, CHECK. The last requirement, before climbing into the wormhole
to depart civilisation, is to farewell my two teenagers, for whom Christmas came early. I load them up with modest piles of gift-wrapped maternal guilt, pull on my adventure boots, bang the heels together, and summon a taxi. ‘Where are you off to?' the driver asks, the obligatory pleasantry. I tell him where, and why. ‘Climate change? Bloody bullshit,' he assures me. ‘I really hope you're right,' I say wearily.

* * * * *

If my taxi driver were interested enough to investigate, he might be surprised to discover that the case for climate change has emerged from, and endured, more than 150 years of intense probing. The history of climate exploration is defined by questioning, bewilderment, inquiry, confirmation, inattention and resistance, falling one on the other like geological strata, archiving within them little morsels of the political and social atmosphere of their respective eras. American physicist and historian Spencer R. Weart provides a fascinating armchair guide in his book and accompanying website
The Discovery of Global Warming
, which informs much of the following abridged romp through some key moments.

Examination of the possibility of climate change began in earnest in the thrust and parry of another red-hot scientific stoush – the Victorian-era question of whether great sheets of ice had once covered much of the Earth. If this was so, what forces could so dramatically shift the thermostat of the planet? This was the matter pondered by a British naturalist, John Tyndall, who in 1859 conducted a series of laboratory experiments and concluded that some gases – mostly water vapour, but also CO
₂
– could indeed trap heat. He theorised that changes in the concentrations of these gases in the atmosphere might have dramatically altered the Earth's climate, and might do so again.

In 1896 a Swedish scientist, Svante Arrhenius, devoted a year to resolving the most mind-blowing mathematical calculations – therapy, so the story goes, for a broken heart. Without benefit of calculators, computers or satellite data, he figured his way through the equations and emerged with the hypothesis that by burning fossil fuels, humans were releasing CO
₂
into the atmosphere, which may eventually warm the planet. By pulling out an atlas and figuring out how much of the Earth was covered by water, by ice, by green forests, by desert, he even deduced how much heat it would suck up or bounce back to space.

British environment writer Fred Pearce, reflecting on Arrhenius' astonishing effort, says the Swede:

virtually invented the theory of global warming … Not only that: his calculation that a doubling of carbon dioxide levels would cause a warming of about 10 degrees Fahrenheit almost exactly mirrors the Intergovernmental Panel on Climate Change's most recent assessment, which puts 10.4 degrees Fahrenheit at the top of its likely warming range for a doubling of CO
₂
levels.

But Arrhenius seems not to have been alarmed at this distant prospect; his interest lay more in the past than the future – in the cycles driving the ice ages.

In the 1930s evidence started to trickle through that temperatures in the US and the North Atlantic were indeed increasing, but still no one seemed particularly bothered. After World War II, and with the escalation of the Cold War, science enjoyed a funding bonanza courtesy of strategic investment by governments, and some of the bounty found its way to climate work. In 1956, Canadian physicist Gilbert Plass revisited the idea that human combustion of fuels may be having an impact on atmospheric CO
₂
levels, publishing predictions that would anticipate the consensus
findings of scientists from around the world some 50 years later. A year later American oceanographer Roger Revelle investigated the riddle of whether the oceans had enough appetite for CO
₂
to soak up rising fossil-fuel emissions, and concluded that they did not – the chemical mechanism was just too slow to keep pace. As a consequence, he wrote, greenhouse warming:

may become significant during future decades. Human beings are now carrying out a large scale geophysical experiment of a kind that could not have happened in the past nor be reproduced in the future.

In 1960, the rising atmospheric level of CO
²
was explicitly plotted for the first time by Charles Keeling, a colleague of Revelle's. He had just two full years of measurements from the Mauna Loa Observatory in Hawaii and from Antarctica, but already he could detect a rise. Today decades of observations from Mauna Loa provide, in one simple, chillingly eloquent escalating graph, a compelling narrative of the changing atmospheric story. Its findings were backed up by observations collected in Australia, France, Germany, Italy, Japan, Sweden and elsewhere. In the past two decades air trapped and retrieved from Antarctic ice has confirmed this record of change, allowing scientists to extrapolate the modern story, and to turn the clock back and track CO
²
levels over 800,000 years.

Keeling first measured atmospheric CO
²
at 316ppm; five years later, 1965 – the year of my birth – it was 320ppm. By the time I graduated high school (1983) it had leapt to 342. When my first child was born (1993) it was 356 – already beyond what would later be calculated as the safety zone. By my 40th birthday it was 379. By the time of the Copenhagen assembly, and my flight south, it was 388ppm, and climbing. The Keeling Curve swings ever upwards, the mean line through sharp seasonal zig-zags
tracking the inhalation and exhalation of the planet: dipping down when the great forests of the northern hemisphere sprout leaves and soak up CO
₂
, pushing up when they release it again in the autumn. To trace the predicted trajectories for CO
₂
that will plot my children's life milestones – even those underpinned by more optimistic scenarios – is an exercise guaranteed to trigger more parental guilt than a thousand absent Christmases.

By the 1970s scientists became increasingly active, intrigued, divided and, ultimately, worried about what was going on. By then it had become clear, through analysing geological records, that the Earth we knew emerged from a roller-coaster history of massive climatic shifts, and that these might be triggered by anything from a fierce volcanic eruption to the subtle, rhythmic shift in the planet's orbit. Scientists began busily applying new computer-modelling techniques to try to resolve their many questions, only to discover how little they really knew about that most delicate, complex, fine-tuned and fractious organism, Earth.

Gradually the term ‘greenhouse effect' slipped into ordinary parlance, neatly capturing how the atmosphere trapped heat. Sunlight warms the surface of the planet. In turn, the land and oceans release heat – or infrared radiation – sending it back into space. Greenhouse gases absorb part of this radiation, blanketing and warming the lower atmosphere, conditions human civilisation has evolved to embrace. By now scientists understood that the greenhouse mechanism involved a range of gases, all absorbing infrared radiation, slowing the rate at which the planet can cool and warming its surface.

Many gases in the atmosphere have the capacity to influence global temperatures. As well as CO
₂
(responsible for about 20 per cent of the effect), these include water vapour (the dominant substance, responsible for about 50 per cent of absorption), together with ozone and methane and other minor players, including particles in the air (dust and other aerosols). Clouds are also significant
players, some absorbing infrared radiation and contributing to greenhouse warming, others deflecting sunlight back into space, making their net effect one of cooling. The influence of rising CO
₂
is greater than the proportions might imply, because by raising temperature it creates feedback conditions which amplify the formation of water vapour and clouds. The reverse also applies to exaggerated effect – the impact of removing CO
₂
is approximately seven times that of doubling it, and would bring about rapid cooling.