The Ice

On planet Earth today it could be said that we inhabit the Antarctic moment.  Each year now, tens of thousands of tourists visit a realm that, just a few generations ago, was virtually unknown.  Over the past century we have learned just how different is the Antarctic from theArctic, and the South Pole has moved from the geographical periphery of our consciousness to the centre of our scientific and intellectual concerns.  The physics and politics of global warming have turned our eyes towards the great southern ice cap. Antarcticachallenges us culturally as well as scientifically and politically – it implicates our humanity.  The vast white continent of ice has never before gripped our imagination or dictated our destiny with such power.  How are we to make sense of such a remarkable, otherworldly part of the planet?

One view of Antarctic culture and history is that it has all been about coming to terms with the immensity and meaning of the continent’s vast icy outback.  Antarctic voyagers of the nineteenth century had originally wanted rock.  They wanted rock and soil they could plant a flag in and claim for their country.  The ice was in the way: it was a nuisance, an obstacle.  Later, the ice became a testing ground for physical endeavour, a source of beauty and fear, but still essentially an obstruction stopping them from reaching, studying and claiming the land beneath.  But by the mid-twentieth century, the ice itself had become a primary scientific focus and was no longer regarded just as an obscuring and frustrating ‘barrier’ between visitors and the much-desired land.  Scientists began to see ice as a mineral of interest in itself; they began to see glaciers as geological andAntarctica as a vestigial landscape, a giant white fossil.

In the early 1950s it was discovered that the ice sheets were not just a few hundred metres thick but actually kilometres deep, and so the driest of all continents was really a vast elevated plateau of frozen water.  This startling discovery revealed that world sea level is principally controlled by the state of the Antarctic ice sheet.  Questions about the ice changed from how frustrating, to how vast, how continental, how deep, how old, and then to how stable?  The Deep Sea Drilling Project of the early 1970s revealed how much older the Antarctic ice cap is than theArctic.  And the confirmation of global warming due to human influence came not only from the behaviour of the ice sheet, but also from the air bubbles trapped within it.  Before Antarctica was even seen by humans, it was recording our impact.

Ice cores are the holy scripts, the sacred scrolls of our age.  It was ice that would deliver the scary sense of urgency that we now feel about global warming.  The oldest Greenland cores go back to the last interglacial, about 120,000 years ago, whereas the deepest Antarctic cores currently retrieve 800,000 years of climate history.  In Antarctica, there is less precipitation and seasonality and more compression of the layers of ice; resolution is thus traded for time.  InGreenlandthe layers are clearer because of the greater annual accumulation of ice.  And so the more discriminating Greenland cores are essential to calibrating the longer, more condensed Antarctic archive.  The polar ice caps therefore combine beautifully to give us detailed long-term climate data.  And at the small icecap near Casey station – the Law Dome, appropriately named after the spectacularly bald former Director of the Antarctic Division, Phillip Law – some especially discriminating atmospheric narratives have been extracted.

If 100 years ago the defining Antarctic journey was the sledging expedition across the surface of the ice, and 50 years ago it was the tractor traverse that, with seismic soundings, measured the volume of the ice sheet, then the defining Antarctic journey of our own era goes straight down, with the help of a drill, from the top of the ice dome to the continental bedrock, a vertical journey back through time.  And the ice core thus extracted enables us to see our civilisation in the humbling context of hundreds of thousands of years of climate history.  Right now in Antarctica, the international race is on again – not for the South Pole, not for the first trans-Antarctic traverse, but for the first million-year ice core.

For more on ice as a key to understanding climate change, see Tom Griffiths’ essay ‘A Humanist on Thin Ice’ in the Griffith REVIEW (no. 29, August 2010): http://griffithreview.com/edition-29-prosper-or-perish/a-humanist-on-thin-ice