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7 April 2017

An Alaskan Glacier Has Just Reached Its Lowest Point in 900 Years

Img: Wikimedia Commons/Nomadic Lass 
Across the world, glaciers are almost uniformly retreating. In 1910, the Glacier National Park in Montana contained more than 150 glaciers, but today there are less than 30 left, most of which are at least two-thirds smaller than when first recorded. There’s no harder evidence for the ongoing effects of global warming than glacier decline.

In Alaska, there are around 50 coastal glaciers, and the Columbia Glacier is one of the most famous, but now it’s cultivating a different reputation – it’s the biggest single contributor to sea level rises in Alaska. Now, the Columbia Glacier has retreated to its lowest point in 900 years. Researchers were able to determine this because the glacier has just receded past the point of intersection between two different chemical compositions in the rock, and sedimentary testing revealed that the last time those two chemicals mixed was 900 years ago.

While Columbia has been retreating since 1910, it has only begun this new, more rapid pace of retreat in the last 30 years. All signs point to the cause of this being manmade, as the rate of retreat directly matches data on greenhouse gas levels and global warming. This is one of the few cases where the movement of a glacier in such a tectonically unstable area can be directly attributed to temperature changes. Such a revelation is ground-breaking, but also deeply disconcerting.

Most environmentalists agree that in order to stem the tide of climate change, the planet cannot be allowed to get any more than 2°C warmer, but the ongoing retreat of Columbia and other water terminating glaciers demonstrates that even that lofty goal might be too little too late. Elsewhere in the world, glaciers are retreating to reveal trees which are over 7000 years old.

In the Andes, record-breaking El Niño air currents have resulted in a rapid increase in glacial melting, reducing the life expectancy of many glaciers to decades, where previously it had been centuries. On a global scale, the first decade of the 21st century had a melt rate three times higher than the 20th century, and new records are being broken on a yearly basis.

Even beyond rising sea levels, losing glaciers have a massively detrimental effect on the surrounding environment. Many animals and planets rely on glaciers, and when one species goes into decline, it creates an imbalance which ripples through the entire eco-system. For instance, stoneflies use glacial streams to raise young, and projections show that with the melting rates still rising, the species could be gone in as little as 20 years. 

Callum Davies

Callum is a film school graduate who is now making a name for himself as a journalist and content writer. His vices include flat whites and 90s hip-hop.