Global Warming Puts New Zealand Glaciers Past the Tipping Point

The ‘Southern Alps’ of New Zealand in winter. (Photo by Lasse Holst Hansen)

(CN) — Glaciers in the Southern Hemisphere, located in New Zealand, are past a tipping point in terms of ice loss due to climate change.

The Southern Alps, or Kā Tiritiri o te Moana as they’re known by the indigenous Maori, have lost more ice since the pre-industrial era than what remains today according to a study published Friday by a group of researchers at the University of Leeds in collaboration with the National Institute of Water and Atmospheric Research (NIWA).

The retreat of ice from the glaciers has denuded the landmass, leaving behind a changed landscape.

Not even the snowy caps of the Southern Alps are immune to climate change.

According to the National Oceanic and Atmospheric Administration, Earth experienced its second warmest November on record last year. Record temperatures were recorded in North America, South America, Europe, the southern half of Africa, northern and southern Asia, Australia and New Zealand, according to the report.

The study authors measured volume changes for 400 mountain glaciers across the Southern Alps for three timeframes. The first is the longest snapshot from roughly 400 years ago to 1978, followed by 1978 to 2009 and 2009 to 2019, according to the study published in the journal Scientific Reports.

Results show that ice loss has doubled since the glaciers peaked during the last Little Ice Age. Compared to recent decades the glaciers lost up to 77% of their total volume according to the study authors.

About 17% of the volume was lost between 1978 and 2019 alone according to the study authors and last year, just 12% of ice mass was left behind in the former, low altitude section of the Little Ice Age glacier region.

Study author Dr. Jonathan Carrivick from the Leeds School of Geography says the study illustrates a trend in New Zealand’s ice loss.

“The acceleration in the rate of ice mass loss may only get worse as not only climate but also other local effects become more pronounced, such as more debris accumulating on glaciers surfaces and lakes at the bottom of glaciers swell, exacerbating melt,” said Carrivick in a statement.

He says the ice loss may have likely passed the “peak water” or tipping point of glacier melt supply.

Rob Roy glacier in the Matukituki valley in December 2018; this glacier on steep hill slopes is now disconnected from a (out of sight) valley floor part. (Jonathan Carrivick, University of Leeds)

The New Zealand Southern Alps run about 310 miles along much of the length of the south island. A survey conducted in the 1970s showed approximately 3,000 glaciers larger than 2 ½ acres. A small portion of glaciers in the region saw some growth during the 25-year period starting in 1983 according to a previous NIWA study, but that was short-lived and the rapid rate of melt has since been the prevailing trend according to the recent study.

In an email, Carrivick said, “The takeaway message is we are in unprecedented times, the glaciers and thus the alpine landscape and rivers, have never been changing so fast as now when compared to the last millennium.”

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