Our Changing World

How fast - and how completely - could Antarctica's smaller western ice sheet melt in a warming world? An international science team, led by Aotearoa New Zealand, set out to investigate whether two degrees of warming could already be a tipping point for the frozen continent.

Antarctica is losing ice at an accelerating rate, particularly in some parts of West Antarctica.

How did the small and more vulnerable West Antarctic Ice Sheet behave during past periods of natural warming? Geological evidence is sparse, but an ambitious sediment-drilling project aims to change that.

Drilling back in time to explore past periods of warming

SWAIS2C - short for Sensitivity of the West Antarctic Ice Sheet to 2°C - is an international collaboration, co-led by Aotearoa New Zealand. During its first season this summer, the team set up camp close to the grounding line of the Ross Ice Shelf, where the world's largest slab of floating ice is at its thickest. Below more than 580 metres of ice, only about 50 metres of ocean separate the bottom of the ice from the ocean floor.

The team used hot water to thaw a hole through the ice to reach the seafloor where layers of mud and rock have been accumulating for millennia, building up one of Earth's memory banks of environmental conditions at the time they were deposited.

Saving the world's largest ice shelf

The SWAIS2C team successfully retrieved the longest sediment core ever extracted from the remote Siple Coast, which holds clues about the ice sheet's more recent past. Next season, the team hopes to drill deeper and further back in time to the last interglacial period, some 125,000 years ago, when Earth was around 1.5°C warmer than pre-industrial temperatures - similar to the warming we are approaching now.

The goal is to track whether the grounding line of the Ross Ice Shelf retreated or advanced during this and even earlier periods of natural warming, and what that tells us about the risk of the West Antarctic Ice Sheet breaking up partly, or even completely, in the future.

If the floating Ross Ice Shelf were to melt, it would have no impact on sea levels. But the ice shelf acts as a buttress, holding the West Antarctic Ice Sheet in place. If the shelf goes, the ice sheet would likely follow - and the consequence could be 3-5 metres of sea level rise. …

Go to this episode on rnz.co.nz for more details

Allergenic pollen is a big trigger for New Zealand's high rates of hay fever and asthma. But for 35 years, we've had no current data on pollen levels. Until now. Justin Gregory talks to a team who want to change that.

The view is what you notice first.

It's takes time to get up to the roof of the Auckland War Memorial Museum Tamaki Paenga Hera but once you're there, it's worth it. A 360-degree turn takes in all the major sights of central Auckland. If you weren't looking for it, you might not notice a green, medium-sized metal device placed just so to catch the breeze. This device, a clockwork volumetric spore trap, is the key to learning more about pollen levels in this country - a major cause of asthma and hay fever.

New Zealand's first pollen trap in 35 years

Asthma affects approximately one in eight adults and one in five children in New Zealand, with rates higher than those in Australia or the UK. Yet, for the past three decades, the country has operated without a single pollen trap - until now.

Associate professors Stuti Misra and Amy Chan from the University of Auckland co-lead a team operating the country's first pollen trap in 35 years. Since July 2023, the team has been trapping pollen and spores, identifying and counting them. Their mission is to update the data on New Zealand's pollen and understand its correlation with the country's soaring asthma and allergy rates.

Climate change sends pollen rates soaring

Their research is funded for just a year, but good data is already emerging about seasonal variations in pollen. The team already know the number of high pollen count days has increased by 75 percent over the last 30 years, likely due to climate change. This increase not only signifies an earlier onset of the grass season but also a higher volume of pollen in the air - posing a greater threat to those with respiratory issues.

Amy is running a related clinical trial, developing real-time prediction tools and smart devices to avoid asthma attacks. Using individualised data like sleep patterns, breathing rate, weather information, medication use and weather, she hopes to determine what information can most accurately predict an attack and develop tools to warn sufferers.

Listen to the episode to learn more about why pollen levels are rising, what technology is emerging to measure those levels and how smart phones and watches could be key to managing and preventing asthma attacks. …

Go to this episode on rnz.co.nz for more details

Giant kelp is disappearing from Wellington Harbour. Love Rimurimu is aiming to restore lush underwater kelp forests with an ambitious and collaborative replanting effort. Claire Concannon dives in to the wonderful world of seaweeds.

The aquarium room at NIWA is awash with sound. A pump system hums, clicks and splashes as it circulates water through large tanks like the Wellington bucket fountain. 

Inside, tiny seaweed fronds tied onto rocks dance in the currents.

Growing kelp

These fronds might be small - a few centimetres at most - but they can grow into lush forests. Giant kelp (Macrocystis pyrifera) starts out in a lab as microscopic spores, before it is coaxed through each phase of its life cycle by staff from the Love Rimurimu project and phycologist Dr Roberta D'Archino. 

After growing a few more centimetres, the kelp will be returned to the wild, part of an ambitious effort to restore the seaweed ecosystems of Wellington harbour. 

Love Rimurimu

Love Rimurimu began as an educational programme delivered by Mountains to Sea Wellington, says project lead Zoe Studd. Local rangatahi were encouraged to learn more about seaweed, to get into the ocean and have a look around, and to learn about why kelp was disappearing.

But when students from Kura Kaupapa Māori o Ngā Mokopuna suggested that they should be actively growing kelp to plant back out, Love Rimurimu took on a new direction.  

Now, the project is piloting plant-outs to help regenerate the giant kelp forests that are so vital to a healthy underwater ecosystem, working with Taranaki Wānui ki Te Upoko o Te Ika, NIWA, Victoria University of Wellington, the kura, and the local community.

Listen to the episode to learn about the stressors impacting kelp, to hear how giant kelp is grown in a lab, and to meet some of the Love Rimurimu team who have been planting out kelp in their blue backyard.  …

Go to this episode on rnz.co.nz for more details

In the final instalment of the summer science series, science communication students tackle two controversial topics: medicinal cannabis, and AI consciousness.

In our final instalment of the summer science series, we have two more stories from science communication students.

Each year, science communication students at the University of Otago's Department of Science Communication are tasked with producing a podcast on a controversial science topic.

In this episode, we hear two of those stories - on artificial intelligence and medicinal cannabis - from Marika Ljunberg and Rhys Latton.

The engineer and the ghost

In June 2022, Blake Lemoine, a software engineer at Google's Responsible AI division, decided to go public. For a period of time, he had been talking to his executives about his firm belief that the chatbot they were developing, LaMDA, had gained consciousness. But Lemoine's executives were convinced he was mistaken.

How can we know whether an artificial system is conscious? What should we do if we realise we have created artificial conscious entities? And should we try and create them at all?

According to neuroethicist Dr Michele Farisco, conscious AI is the only way we can make sure that AI is developed safely: by giving it a moral sensibility. But not everyone agrees that this is a good idea.

Listen to the episode to learn more about ethics and artificial consciousness, and explore the question: what's humane for the non-human?

Music credits:

• Contemporary New Age Theme 9 by Mac Squier (BMI) CAE/IPI#420010737, publisher Mac Squier Music (BMI)
• Busy by Lenny Williams (BMI) CAE/IPI#195221668, publisher Harry L. Williams Music Publishing (BMI)
• Background Info by Lenny Williams (BMI) CAE/IPI#195221668, publisher Harry L. Williams Music Publishing (BMI)
• Clock Mallets by Lenny Williams (BMI) CAE/IPI#195221668, publisher Harry L. Williams Music Publishing (BMI)
• Gentle Harp Underscore by Lenny Williams (BMI) CAE/IPI#195221668, publisher Harry L. Williams Music Publishing (BMI)

Medicinal cannabis: the hazy world of evidence and efficacy

Medicinal cannabis is a now legally available treatment option in Aotearoa through your GP, but many doctors are hesitant to prescribe it due to a lack of solid evidence of its efficacy.

One of the reasons cannabis is controversial is that there is no single condition where cannabis is the preferred, first-line treatment option, says Dr Peter Radue from the Department of General Practice and Rural Health at the University of Otago. …

Go to this episode on rnz.co.nz for more details

Should we intervene to prevent hybridisation between an endangered species and its common relative? In this week's summer science episode, two students from the Department of Science Communication at the University of Otago tell stories of science controversy: the conservation conundrum of hybrids, and the relationship between western science and mātauranga Māori.

Each year, science communication students at the University of Otago's Department of Science Communication are tasked with producing a podcast on a controversial science topic. In this episode, we hear two of those stories - on the issue of hybrids in conservation, and on mātauranga Māori - from Janice Huang and Jodie Evans.

How should we manage hybrid species in New Zealand?

Hybridisation is the mixing of genes from different species or subspecies. Throughout history, humans have harnessed this powerful force to create desired crops and domesticated animals.

But in the field of wildlife conservation, hybridisation can threaten some species with extinction.

In New Zealand, one example is the kakī or black stilt, a nationally critical, all-black wader bird that lives in the braided rivers of the Mackenzie basin. Kakī can hybridise with their closest relative, the poaka or pied stilt.

The kakī population, numbering around 156 wild adult birds, is closely managed to prevent hybridisation.

Listen to the episode to hear contrasting opinions on the plight of the kakī and other organisms threatened by hybridisation.

In defence of mana: Mātauranga Māori and science

Mātauranga Māori translates to Māori knowledge. It's a system that evolved before European contact as Māori encountered new climates, geography, flora and fauna in Aotearoa.

Over the past few years its comparison to western science has ignited significant controversy within the scientific community. The debate came to a peak in 2021 when seven University of Auckland professors signed an open letter to the Listener opposing the integration of mātauranga Māori with secondary school science.

Fostering mātauranga Māori is not about replacing science, says Professor Georgina Stewart, who studies the relationships between science, education language and knowledge.

Increasing mana (respect) for the subjects of research - materials, beings or places - will improve Aotearoa's science with better outcomes for all scientists, says Gemella Reynolds-Hatem, a wāhine Māori student who is passionate about her whakapapa and the value it brings to her study.

Listen to the episode to hear Georgina's expert commentary and the lived experiences of Gemella as she navigates academia…

Go to this episode on rnz.co.nz for more details

Kākā numbers are skyrocketing in Te Whanganui-a-Tara Wellington thanks to conservation efforts. The summer science series continues with a walk through Zealandia to find out why you shouldn't feed these inquisitive parrots.

Our summer science series continues with a story from Samantha Lloyd-Evans, a student from the Centre for Science in Society at Victoria University of Wellington.

Samantha takes us for a walk in Te Whanganui-a-Tara Wellington, where kākā numbers have skyrocketed in recent years, thanks to conservation efforts. 

This increase in kākā has led to an increase in human-kākā interactions, as people learn how to live with these large endemic parrots. 

For the most part, encounters with these inquisitive birds are positive. But seemingly helpful actions such as feeding kākā can have unintended consequences, says Ellen Irwin, lead conservation ranger at Zealandia Ecosanctuary.

Why feeding kākā is a bad idea

Wellingtonians feeding kākā in their backyards can cause a nutrient imbalance in the diet of kākā chicks, Ellen explains. This can lead to metabolic bone disease and other complications, and the chicks often die in the nest.

There are other risks to bird feeding as well, such as attracting pests or accidentally giving the kākā too many calories, similar to getting a toddler hyped up on sugar. 

These risks are why Zealandia and other conservation groups are pushing to educate locals on how to safely interact with native wildlife.

Planting natives in your garden, practising responsible pet ownership, and joining your local trapping group are actions you can take to help native birds like kākā. Ellen also encourages the use of apps like iNaturalist to keep track of the birds seen in Wellington.

Join Ellen for a stroll through the lush ngahere forest of Zealandia while discussing Wellington's booming kākā population and how you can help them.

Learn more:

• Kākā have also made a comeback in Õtepoti Dunedin thanks to Orokonui Ecosanctuary.
• In Wellington, it's not just kākā too: urban bush birds are doing well in the capital, Alison Ballance reported in this 2018 episode.
• Meet some of the non-bird residents at Zealandia Ecosanctuary with Claire Concannon in this episode from May 2023.

Go to this episode on rnz.co.nz for more details

The summer science fun continues with an episode from RNZ podcast Voices. Meet Gaia Dell'Arriccia, a scientist originally from the south of France who studies the seabirds that live around Auckland's coastlines.

A seabird colony at night is a noisy place. But it's also an incredible experience to have thousands of birds flying around you, says seabird scientist Gaia Dell'Arriccia.

The summer science series continues this week with an episode from Voices, an RNZ podcast that tells the stories of the one-quarter of New Zealanders born overseas.

Host Kadambari Raghukumar meets Gaia at the Ōrākei Basin, where she is monitoring a shag breeding colony.

Listen to hear about Gaia's work studying the seabirds around the Auckland coast and offshore islands, and her journey from the Mediterranean to Aotearoa.

Learn more:

• Scientists are also studying the feathers of museum specimens to figure out how Auckland's seabird populations are changing: What feathers can tell us about the past lives of seabirds.
• Meet another passionate seabird scientist, Edin Whitehead, in For the love of seabirds.
• Visit one of Auckland's seabird hotspots in our two-part episode on the Noises Islands: Part 1 and Part 2.
• Head out onto the streets of Auckland with the petrel patrol in search of crash-landed seabirds.

Go to this episode on rnz.co.nz for more details

The summer science series kicks off with an episode from award-winning podcast Black Sheep, about a backyard inventor called Victor Penny who sparked sensational headlines about death ray inventions in 1935.

In 1935, a series of extraordinary newspaper articles claimed a backyard inventor called Victor Penny was trying to build a death ray for the New Zealand government.

Follow Our Changing World on Apple Podcasts, Spotify, Stitcher, iHeartRADIO, Google Podcasts, RadioPublic or wherever you listen to your podcasts.

Welcome to the summer science series from Our Changing World. We're kicking off the holiday season with a science-themed episode from award-winning history podcast Black Sheep.

Victor Penny was a self-taught engineer and inventor who worked with early radio technology - and at a secret government laboratory on Matiu/Somes Island.

Listen to find out the truth - and the science - behind the sensational 'death ray' headlines.

Learn more:

Hear the story of the first radio broadcast in New Zealand in 100 years of radio and the spectrum of light.

Listen to more Black Sheep episodes.

Go to this episode on rnz.co.nz for more details

This week on Our Changing World RNZ podcast producer, and occasional dinosaur correspondent William Ray visits Ngā Taniwha o Rūpapa Dinosaurs of Patagonia, a special exhibition at Te Papa Museum to discover the surprising link between the giant dinosaurs of Patagonia, and prehistoric New Zealand.

Follow Our Changing World on Apple Podcasts, Spotify, Stitcher, iHeartRADIO, Google Podcasts, RadioPublic or wherever you listen to your podcasts

This week on Our Changing World, RNZ podcast producer and occasional dinosaur correspondent William Ray visits Ngā Taniwha o Rūpapa Dinosaurs of Patagonia, a special exhibition at Te Papa Museum, to discover the surprising link between the giant dinosaurs of Patagonia and prehistoric New Zealand.

An ancient giant of Patagonia

One hundred and one million years ago, an astonishingly large animal breathed its last breath on a muddy riverbank in what would eventually become Patagonia in Argentina.

We don't know exactly how it died. Possibly it just got stuck in the mud, a potentially fatal prospect for an animal that weighed as much as eight African elephants.

Its 2.4-metre-long, 600-kilogram femur was eventually unearthed by an Argentinian farm worker, and later inspected by paleontologists from Argentina's Museo Paleontológico Egidio Feruglio. The femur was identified as belonging to a massive long-necked sauropod dinosaur dubbed Patagotitan mayorum, which ranks among the largest animals to ever live on land.

Our Changing World producer William Ray discovers the story of how these enormous animals evolved - and their surprising link to Aotearoa New Zealand.

Special thanks to Te Papa Museum and the Department of Conservation for the soundscape in this episode.

Learn more:

Earlier this year, William reported the story behind another dinosaur exhibit: a pair of Tyrannosaurus rex fossils at Auckland Museum.

For more fossils of ancient giants, check out our episode about the huge penguins that once roamed Aotearoa.

Go to this episode on rnz.co.nz for more details