Glaciers in the Southern Alps began to melt twice as fast

Research conducted by the University of Leeds in collaboration with the National Institute of Water and Atmospheric Research (NIWA) in New Zealand has mapped ice loss in the Southern Alps from the end of the Little Ice Age (about 400 years ago) to 2019. The work was published in Scientific Reports.

The study found that the ice began to melt twice as fast as the glaciers reached the peak of the Little Ice Age. In recent decades, the Southern Alps have lost up to 77% of the total glaciers.

Climate change has had a significant impact on the melting process of glaciers. Not only are local settlements dependent on glaciers for freshwater, hydropower, and irrigation, but it also contributes to global sea-level rise.

The researchers compared digital models of the glacier surfaces and found that ice loss has doubled since the Little Ice Age. Glaciers have started to melt especially quickly in the last 40 years.

Up to 17% of the volume that was present in the Little Ice Age was only lost between 1978 and 2019. In 2019, only 12% of the ice mass was left from what it was before.

These results quantify the trend in ice loss in New Zealand. The acceleration in the rate of ice mass loss can only worsen, since not only climate, but also other local effects become more pronounced, for example, more debris accumulates on the surface of glaciers, and lakes on the bottom of glaciers swell, exacerbating melting.

Jonathan Carrivick, study author from the School of Geography

Carrywick noted that a plan now needs to be drawn up to reduce the amount of water that flows into local rivers from the glacier, as this affects the quality of local water, as well as the availability, landscape sustainability, and aquatic ecosystems.