http://www.rtcc.org/chasing-ice-a-call-for-urgent-climate-action/
Science writers are constantly on the hunt for analogies to help readers situate climate phenomena on their mental map. But nothing beats seeing something for yourself.
And that's what Chasing Ice - which is still out in cinemas - is designed to do. With very beautiful footage, it makes subject matter that's dry on paper compelling.
Melting glaciers are one of the tangible areas where scientists can see the effects of a warming climate. But reading reports giving constantly-revised estimates about whether glaciers around the world are retreating by a few feet more or less a year loses a bit of impact in the telling.
Even though we use trusty measurements like the length of a football field or the height of a building as a marker, it's really hard to picture.
Chasing Ice charts the progress of National Geographic photographer James Balog's Extreme Ice Survey project. Since 2005, Balog and his team have recorded the retreat of 18 glaciers in Iceland, Greenland and the US using 27 cameras.
Through time lapse photography, Balog charts "geologic change", as he puts it. In the space of five years, he documents movements in the landscape that he says we'd normally expect to occur over thousands.
Balog and his team are obsessed with providing scale. As he abseils down a yawning moulin, a colleague volunteers to join him to give a point of reference.
And orange lines superimposed on the footage of glaciers help indicate the amount by which ice masses have retreated. Good old multiple football field lengths appear to illustrate the retreat on screen.
History in motion
The footage also captures the mechanisms shrinking the world's big ice masses. In the film, we can see things that are normally illustrated in diagrams - like the conveyor belt mechanism that pushes melt water into the sea.
The team captures a huge calving event at the Ilulissat Glacier in Greenland, throwing up chunks of ice two to three times higher than the skyscrapers in Manhattan. And more mundanely the film shows wells of Cryoconite - goop made of of dust, carbon and algae that accumulates in holes in the Greenland ice sheet, absorbing heat and increasing the sheet's melt zone.
Scientists do pop their heads in occasionally to put what's happening into wider context. One of the issues that may appear controversial to the public is that some glaciers have grown while others are melting - a fact some news outlets have disproportionately focused on.
But the growing glaciers are in the vast minority - a fact the film elegantly illustrates with a US case study. 1400 glaciers existed in the Yukon in 1958. But by 2007-8, one glacier advanced, 523 glaciers disappeared, 876 glaciers retreated and 22 per cent of the area covered by ice 50 years ago is now ice-free.
It makes sense that Balog, a photographer who studied geomorphology, would want to provide footage of these visual yardsticks of climate impacts.
He reveals that he was a climate skeptic who distrusted mathematical models that told him humans were changing the climate until 12 years ago, when he started to see evidence from ice cores and glacier retreat. So he's made a gargantuan infographic to help everyone else get it, too.
