Shrinking glaciers near crisis

New Zealand’s longest glacier has lost 5km to global warming and is expected to lose at least as much again if the climate keeps heating up.

The Tasman Glacier, the massive ice river that sweeps past Aoraki-Mt Cook, has already shrunk to 23km, from the formation of a 5km lake at its snout in the past 30 years.

In that time, New Zealand’s glaciers have lost almost 11 per cent – 5.8 cubic kilometres – of their ice, new research released yesterday has found.

Twelve of the largest in the Southern Alps are unlikely to return to their earlier lengths without “extraordinary cooling of the climate”, says the National Institute of Water & Atmospheric Research (Niwa).

The warming climate is responsible for more than 90 per cent of the ice loss.

The report comes a day after the starkest warning yet from the Intergovernmental Panel on Climate Change, which declared the impact of global warming could be “abrupt or irreversible” and no country would be spared.

Niwa said the shrinking of New Zealand’s glaciers had continued despite there being virtually no change in the amount of snow feeding them last year.

The shrinkage of the big glaciers, mostly in the Mt Cook region, is driven mainly by the formation of glacier-snout lakes – which encourage big lumps of ice to break off and accelerate the shrinkage – and surface melting.


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