Climate change: What the new IPCC report says is in store for New Zealand

The latest report from the UN's climate change body is being described as "frank and blunt", "sobering and authoritative" and "nothing but bad news" by Kiwi scientists who have read it.

One even said they felt "a little sick" at times, and that it was time for politicians to "do their job" and fix it. 

The epic AR6 Climate Change 2021 - Sixth Assessment Report from the Intergovernmental Panel on Climate Change is nearly 4000 pages, bringing together years of research from climate scientists from around the world. 

It paints a horrifying picture of what humanity is doing to the climate, saying 50-year heatwaves could become almost annual events and not ruling out a sea level rise of 15m in the next couple of hundred years and 22m in the next two millennia if emissions aren't reined in. 

"They've made it an absolute statement of fact - that humanity is causing climate breakdown," Oxfam Aotearoa executive director Rachel Le Mesurier told The AM Show on Tuesday. "We all know about the frog in the boiling water, don't we?  What we've actually got now is we're in this warm water and there are bubbles coming up around us."

"It makes for very sobering reading," Green Party co-leader James Shaw told Newshub. "It's very clear the window of opportunity is closing, but there is still time if we act now. This report's a really big deal - there's something like 14,000 scientific reports that have gone into it. This is the global view of the science community around the world. 

"We need to act urgently and we need to act comprehensively right across the economy, in every community, in every sector of the economy, to start to reduce our emissions over a sustained period of time." 

What the report says about Aotearoa

New Zealand won't escape the effects of the warming climate. We're mentioned dozens of times in the report.

Our mean temperature has increased about 1.1C since records began (page 3522 of the report), "with human influence the dominant driver". 

"Decreases in snow and ice or increases in pluvial/river flooding will affect sectors such as winter tourism, energy production, river transportation, and infrastructure," it says on page 132 - and that's just with 2C of warming compared to pre-industrial times, which we'll likely reach by mid-century at the present rate.

"Fire weather is projected to increase throughout Australia and New Zealand," it reads on page 136 - again, with just 2C of warming. "Fire weather is projected to increase throughout Australia and New Zealand. Snowfall is expected to decrease throughout the region at high altitudes in both Australia and New Zealand, with glaciers receding in New Zealand."

Wellington and Dunedin in particular will become far more at risk of fires, the report said (page 3197). 

The south and west of the country will likely get wetter while the north and east dry up (also page 3197).

"As the climate warms, the tracks of storms are moving towards the poles in many regions, notably across the Southern Hemisphere," said James Renwick, one of the report's lead authors and a climate change professor at Victoria University. 

"At the same time, the high-pressure regions in the subtropics are expanding polewards. The net effects for New Zealand are that the west and south will see increases in precipitation in winter and spring, while the north and east will see reductions."

Rivers will be more likely to flood, marine heatwaves will become more common and last longer, particularly coming from the Tasman Sea (also page 3197). The ocean around New Zealand has warmed more quickly than the global average (page 3200), particularly around the South Island. 

If temperatures rise more than 3C New Zealand will likely lose all of its glaciers, the report says on page 2160, along with up to three-quarters of glaciers around the globe. 

James Renwick. .
James Renwick. Photo credit: Supplied

There will be between 30 and 50 percent fewer 'frost days' than there used to be (page 3194).

"Agricultural and ecological" droughts will be more common (page 3196), landslides will be more likely in the South Island and eastern half of the North Island thanks to "total precipitation rates, precipitation intensity, mountain permafrost thaw rates, glacier retreat and air temperature" (page 3195) and there will be a "continuing reduction in snowfall during the 21st century" (page 3198). 

From 2030, areas below 1500m will likely go without snow for entire years.

"As mean sea-level rise is projected to continue for at least several more centuries, there is very high confidence that this will lead to large increases in the frequency of extreme sea-level events in Australia and New Zealand," the report says on page 3518. 

Kiwi scientists and academics respond

Many New Zealanders were involved in the science behind the report, as well as writing it. One of those, University of Canterbury international relations professor Bronwyn Hayward, said the report showed things are getting worse much faster than the IPCC's 2018 report predicted. 

“The report doesn’t put a precise date on when we know we have crossed the dangerous threshold of 1.5 degrees Celsius of warming, but says unless we make far-reaching change, this will occur over the next 20 years using average temperatures. This will expose many more people and our natural environment to even more devastating consequences including intense flooding, storms and unprecedented droughts and fires."

Kiwi cities are particularly at risk, she said, "as hotspots where the experience of localised heat and flooding will be more intense than global averages. This matters because cities in New Zealand are already home to nearly 90 per cent of our population." 

She said it was time to stop "magical thinking" that technology would solve the problem before it was too late. 

Franz Josef Glacier in 2007 and in 2021.
Franz Josef Glacier in 2007 and in 2021. Photo credit: Christoph Kraus

Iain White, a professor of environmental planning at the University of Waikato, thought he was desensitised to alarming climate reports before sitting down to read this latest one. 

"I actually felt a little sick at a couple of paragraphs. I feel for the scientists who have to put this together."

He said the emissions reduction plan the Government is required to deliver by the end of this year will be "vitally important", but is sceptical authorities will act with enough urgency. 

"At the same time as politicians in Wellington react to this report with concern, climate advocacy groups are suing Auckland Transport and Auckland Council over a long-term Land Transport Plan that fails to reduce emissions. It’s a sign that our institutions helped create the current situation, and action may involve new governance structures or fundamental changes to leadership, budgets, or sectors."

He also pointed to locals who oppose efforts to make streets safer and better for cyclists and pedestrians over cars.

"If anyone is in doubt at the scale of the challenge, reflect on how hard it was to reorient just a few individual streets towards walking and cycling during the Innovating Streets trial. Now do that to a city. Or a sector."

Nick Cradock-Henry, a scientist at Landcare Research, said drought was now "Aotearoa New Zealand’s costliest hazard, with economic and social implications for rural communities" - and the report predicts things will only get worse - and farmers need to adapt, as well as cut emissions. 

"Mitigation will be insufficient to address the changes in climate presented here. To ensure sustainable long-term futures for Aotearoa New Zealand, the report is a stark reminder of the need for adaptation. Adaptation will require strategic and even radical adjustments to practices, processes, capital, and infrastructure in response to climate change, and must begin now.”

Sara Mikaloff-Fletcher of NIWA said New Zealand's strategy of offsetting carbon emissions with new forests will become increasingly infeasible.

"Models predict extreme temperatures and droughts brought on by climate change will weaken the ability of forests and other green spaces to absorb carbon dioxide. This is particularly significant for Aotearoa New Zealand, because our forests and land use offsets roughly a third of our total greenhouse gas emissions."

Luke Harrington, a senior research fellow at Victoria University's Climate Change Research Institute said the report's predictions for New Zealand were likely the most accurate yet. 

"Some climate models can struggle with our thin, mountainous wedge of land sticking out of the ocean. The emphasis on never using climate models beyond their limitations, understanding precisely what those limitations are, and always working with local knowledge and contexts when making local decisions, seems to ring true for Aotearoa just as with the rest of the world - particularly as we adapt to an ever-changing climate over the coming decades."

Lauren Vargo, a research fellow at Victoria University's Antarctic Research Centre, said seafood around New Zealand would be impacted.

"The impacts on New Zealand will likely include: sea level rise, which will lead to more frequent and extreme flooding and erosion; increases in extreme rain and flooding in some regions, but increases in drought in other regions; decreases in glacier ice and seasonal snow, leading to impacts on water resources, hydropower, and tourism; and increases in ocean warming, which will impact resources like seafood in New Zealand."