Columbia Glacier in 2009 and 2015. Image: James Balog/Extreme Ice Survey

Climate Scientists Release Un-Retouched Photos of Past Glaciers vs Today

This is what climate change looks like.

CARLY CASSELLA
1 MAY 2017
 

Climate change is a notoriously difficult concept to visualise, but a confronting new paper published this week by the Geological Society of America makes climate science more accessible by showing the impact that up to 100 years of warming have had on glaciers around the world. 

 

The paper aims to improve public awareness of our planet's disappearing glaciers by offering straightforward, photographic proof.

"We have unretouched photographic evidence of glaciers melting all around the globe," says co-author Gregory Baker, a geologist at the University of Kansas.  

"That includes the ice sheets of Greenland and Antarctica - they're reduced in size."

The paper reveals a series of images that plainly illustrate how far glaciers have retreated in the past century.  

"These aren't fancy computer models or satellite images where you'd have to make all kinds of corrections for the atmosphere," explains Baker.

"These are simply photos, some taken up to 100 years ago, and my co-authors went back and reacquired photos at many of these locations. So it's just straightforward proof of large-scale ice loss around the globe."

 

This is the Mendenhall Glacier in Alaska, photographed in 2007 (top) and 2015 (bottom). It's retreated around 550 metres (about 1800 feet) during that time:

glacierb1

glacierb2James Balog and the Extreme Ice Survey

The title of the paper, "Savor the Cryosphere", was chosen by the authors to highlight our dependence on the cryosphere - the frozen bits of our planet's surface. 

"This loss of ice has implications to rising sea level, greater susceptibility to dryness in places where people rely upon rivers delivering meltwater resources and to the destruction of natural environmental archives that were held within the ice," the paper reads.

Below is the Stein Glacier in Switzerland, photographed in 2006 (top) and in 2015 (bottom image):

glacierd1

glacierd2James Balog and the Extreme Ice Survey

The loss of ice is also steadily erasing Earth's geological history - ice cores contain little bubbles of ancient atmosphere that can give scientists a glimpse into the climate of the past.  

The information stored in these glaciers goes back hundreds of thousands of years, and could provide scientists the information they need to prepare for the effects of rising levels of carbon dioxide in our atmosphere. 

 

"Analysing ice cores is one of the best ways to analyse carbon dioxide in the past, and they contain pollen we can look at to see what kind of plant systems may have been around," says Baker

"The more that glacial ice melts, the more we're erasing these historical archives that we may not have measured yet in some remote glaciers, or deep in ice caps, that can tell us the history of Earth that will be gone forever."

Here's Solheimajokull in Iceland, which has retreated around 625 metres (2050 feet) between 2007 (top) and 2015 (below): 

glacierc1

glacierc2James Balog and the Extreme Ice Survey

Alongside the photographs, the authors have included summaries of their own work on the retreat of glaciers, stripped of jargon to make them easier for the layperson to read. 

"It's designed to be a more accessible compilation of some pretty dense scientific publications by the authors," says Baker

This is the Qori Kalis Glacier, an outlet of the Quelccaya Ice Cap in Peru, photographed in 1978 (top) and 2016 (bottom image). It's retreated around 1.14 kilometres (0.7 miles):

glacierf1

glacierf2Lonnie Thompson

This is the Trift Glacier in Switzerland, photographed in 2006 (top) and in 2015 (below). It's retreated around 1.17 kilometres (0.73 miles):

glaciere1

glaciere2James Balog and the Extreme Ice Survey

The study was published in the journal GSA Today.

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