Since the 1970s, Niwa has conducted flights all over New Zealand’s mountain ranges to carry out its end-of-summer snowline survey to observe the state of our glaciers and elevation of the snowline, and to record how our landscape has been changing over time.
Niwa principal scientist and programme lead Andrew Lorrey said overall, the snowline was rising, and in recent years that rise had accelerated.
"We are experiencing a continued trend of glacial ice loss. Even if we got a few cooler seasons, they wouldn’t be enough to undo the damage that has already been done.
"We must tackle the issue of rising greenhouse gases if we are to save our glaciers from melting away."
Dr Lorrey said they covered nearly the full set of glaciers that had been monitored since the ’70s, as well as some of our southern-most glaciers not seen by Niwa since 2018.
"Back then, they were incredibly small and functionally dead, and one is now two-thirds of the size it was on our last visit."
This year, Niwa said the appearance of New Zealand’s glaciers was "smashed and shattered".
Within the past decade New Zealand has experienced seven of the 10 warmest years since recording began, with 2023 being the second warmest on record.
The top-five warmest years on record have all occurred since 2016.
"My colleague Dr Trevor Chinn, who started the survey nearly 50 years ago, put it perfectly. He said that the difference between today and five decades ago is like going to a skifield in the summer and then in the winter.
"That is how stark it is, and it’s not just happening in New Zealand, but all over the world."
Glaciers are an important source of meltwater, which sustains stream habitats and delivers nutrients to lakes, rivers and oceans.
They also feed hydro-electric lakes, affecting the availability of renewable energy and contributing an estimated $100 million into the economy through tourism.
Dr Lorrey said he was worried our glaciers would not be around for future generations to enjoy.
"A warming planet means fewer cold places and less ice.
"New Zealand is one of the few mid-latitude places where people live near glaciers, where people can see and visit them easily. However, this is getting tougher."
