Glacier’s contain less ice than previously thought

Estimates on the extent of sea level rise, and freshwater availability, have both been revised as a result of the new findings. 

Dartmouth College’s Institute of Environmental Geosciences has produced the world’s first atlas measuring the movement and thickness of the world’s glaciers. The result offers a far clearer understanding of the impact of the huge bodies of ice melting.

Analysing more than 250,000 mountain glaciers for both depth and velocity, researchers have concluded there could be around 20% less ice contained in these objects than previously thought. The findings have significant implications,  from power generation to agriculture. 

‘Finding how much ice is stored in glaciers is a key step to anticipate the effects of climate change on society,’ said Romain Millan, a postdoctoral scholar at IGE and lead author of the study. ‘With this information, we will be closer to knowing the size of the biggest glacial water reservoirs and also to consider how to respond to a world with less glaciers.’

‘The finding of less ice is important and will have implications for millions of people around the world,’ said Mathieu Morlighem, the Evans Family Professor of Earth Sciences at Dartmouth, and co-author of the study. ‘Even with this research, however, we still don’t have a perfect picture of how much water is really locked away in these glaciers.’

Overall, 98% of the world’s glaciers are included in the work, the majority of which have now been shown as shallower than once believed. In cases such as the South American Andes, this means around 23% less freshwater is stored in the area, raising alarm bells for millions of people, animals and plant life that rely on this supply.

According to the study, the downgrading is equivalent to California’s third largest lake, Mono, completely drying up. In contrast, other regions were found to have more ice than prior estimates. The Asian Himalayas, for example, are now thought to have 37% more water than past estimates. However, the picture becomes more confusing still as glaciers in this region are melting fast. 

In related news, a 2020 survey of glaciers in New Zealand’s Southern Alps had lost 77% of their volume. Last year, glaciers in West Antarctica were found to be melting at an accelerated rate.

Image credit: Matt Gross