Our Changing World

GLP1 - RA weight loss drugs get the Our Changing World treatment! What are they? How do they work? And what does the science say about the benefits, and the risks? Plus, beyond health outcomes, how might things change as they become more widely available?

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LEARN MORE:

• If you’d like a deeper understanding of how drugs such as Ozempic and Wegovy affect appetite and blood sugar regulation, Emile Donovan spoke to Dr Sebastian Furness about this on Nights.
• Obesity genetics researcher Giles Yeo joined Afternoons to explain why body weight is influenced by much more than willpower, and why biology plays such a powerful role in hunger and weight regulation.
• The study that Dr Andrew Reynolds contributed to on how obesity trends are changing around the world was published in Nature. You can read the paper here.
• Curious about how the major incretin drugs compare? This systematic review and meta-analysis examines the effectiveness of semaglutide, liraglutide, dulaglutide and tirzepatide for blood sugar control and other outcomes.

GUESTS:

• Dr Andrew Reynolds, Department of Medicine, University of Otago

IN THIS EPISODE:

(00:00) Introduction

(01:12) How GLP-1 receptor agonists were developed as treatments for type 2 diabetes

(03:55) The biology of incretins, insulin, glucagon and how these drugs work

(07:20) The drugs available and funded in New Zealand

(11:34) Weight loss benefits, side effects and questions about long-term use

(20:30) Retatrutide, future incretin therapies and the emerging “Ozempic economy”

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

In September, the Chatham Island black robin was crowned Bird of the Year 2026. This small, round and feisty manu has a remarkable comeback story, from just five birds in 1979 to about 400 today. They are found on just two predator-free islands in the Chatham group.

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

Over a hundred years ago Fritz Haber and Carl Bosch discovered a way to produce ammonia that revolutionised farming. It changed the world. But today this way of making ammonia uses between 1-2% of the world's global energy, and produces about the same greenhouse gas emissions as the whole airline industry. Is there a better way? A team at Earth Sciences New Zealand are on the hunt for a catalyst that could convert water and air into ammonia using renewable electricity. Their dream is to enable efficient and economical small-scale ammonia production, but to get there they must first prove the chemistry is possible.

Over a hundred years ago Fritz Haber and Carl Bosch discovered a way to produce ammonia that would revolutionise farming. It changed the world. But today synthetic ammonia production uses between 1-2% of the world global energy, and produces about the same greenhouse gas emissions as the whole airline industry. Is there a better way to make it? A team at Earth Sciences New Zealand are on the hunt for a catalyst that could convert water and air into ammonia using renewable electricty. Their dream is to enable efficient and economical small-scale ammonia production, but to get there they must first prove the chemistry is possible.

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

Over 80% of our coastal dune ecosystems have been lost. So, what about the native species living with them? Ayana Piper-Healion steps into Bream Bay’s sand dunes with a monitoring team to see what lizards can tell us about the health of the sand dunes.

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Learn more:

To find out more on what the local critics think about the Bream Bay Sand Extraction Project’s fast-track application, RNZ’s Peter de Graaf reported on a protest there earlier this year.

Further north, Saturday Morning reported on significant damage being caused to dunes by thrill seekers driving vehicles through them. 

Another region dealing with threatened dunes is Waimarama, where weeds are spreading from people fly-dumping garden waste.

In the Hawke’s Bay, the ‘Skink Squad’ are on a mission to save the northern spotted skinks in preparation for an infrastructure project.

In 2021, Our Changing World did a deep dive into dune plants and the largest supplier of plants for dune revegetation programs.

Guests:

Steve Johnson, Patuharakeke Te Pou Taiao

Ari Carrington, resource co-ordinator at Patuharakeke Te Pou Taiao

Katrina Hansen, biodiversity specialist Northland Regional Council

Laura Shaft, biodiversity manager Northland Regional Council

Brooke Gray, biodiversity advisor Northland Regional Council

Richard Griffiths, coastal scientist Northland Regional Council

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

Highly pathogenic H5/N1 bird flu strain has been detected in New Zealand, but it's still early days. There are lots of unknowns about when it will start spreading here, and how our wildlife will react to the virus. But what has happened in other countries? Claire Concannon speaks to Niall Hatch of BirdWatch Ireland about what they've experienced.

SHOW NOTES:

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LEARN MORE:

• The Great Ireland Vs New Zealand Bird-Off took place across two episodes in 2023, during the time when bird flu has having a huge impact on Irish seabirds. Listen to them here: Part 1, Part 2.
• Read this RNZ explainer about what the confirmation of H5N1 in New Zealand means for wildlife, poultry and the public.
• Revisit the 2025 Our Changing World episode Getting ready for H5N1 bird flu, which traced the virus’s global spread and New Zealand’s preparations for its arrival.
• For more on Irish birds and wildlife with Niall Hatch and Ricky Whelan, you can listen to BirdWatch Ireland’s podcast: In Your Nature.

GUESTS:

• Niall Hatch, BirdWatch Ireland.

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

After years of watching it move closer, the highly pathogenic H5/N1 strain of bird flu has arrived on our shores. It has left a trail of devastation, causing mass mortality events in many birds and mammal species. What do we know about this virus and how is one high-risk site preparing to manage the impacts?

Sign up to the Our Changing World monthly newsletter for episode backstories, science analysis and more…

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

Our Changing World listeners might like to check out All In Her Head, a podcast by investigative journalist Anusha Bradley exploring a complex medical syndrome, and the grey areas where medicine, belief and scientific evidence collide.

See photos, video and read more about Rachel's story in a special digital feature: The girl who couldn’t eat: An RNZ investigation into the controversy over a debilitating illness

A special thanks to the young women and their families for sharing their stories for this series. And thank you to the doctors, surgeons and specialists in New Zealand and overseas for sharing their medical knowledge and expertise.

If any of these stories affect you – you can find more information about EDS, at ehlers-danlos.org.nz - or you can look up EDS NEW ZEALAND on Facebook and Instagram.

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

Our Changing World takes a deep dive into controversial plans by US company Colossal Biosciences, backed by filmmaker Peter Jackson, to de-extinct the Moa. In part two of a two-part series, Sharon Brettkelly looks at whether it SHOULD be done.

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LEARN MORE:

• Check out this explainer from Katie Kenny for the proposed Gene Technology changes.
• RNZ’s Monique Steel looks at who is backing the stalled Gene Technology Bill.
• Listen as Kathryn Ryan talks to Kennedy Warne about how de-extincting the moa might fit with conservation efforts.
• Ben Novak talks to RNZ’s Saturday Morning show about de-extincting the passenger pigeon.

GUESTS:

• Professor Amanda Black, Department of Soil and Environmental Sciences, Lincoln University and Director of Bioprotection Aotearoa.
• Professor Phillip Wilcox, bioethicist and quantitative geneticist, University of Otago.
• Andrew Pask, Chief Biology Officer, Colossal Biosciences
• Associate Professor Nic Rawlence, Director of Otago Palaeogenetics Laboratory, University of Otago.

IN THIS EPISODE:

(00:00) Should we bring moa back?

(01:36) Colossal’s plan to bring back moa

(03:00) Who benefits from de-extinction

(07:33) Māori perspectives, consent and data sovereignty

(10:55) Could New Zealand stop the project?

(14:43) Considering all the aspects of de-extinction

(18:30) De-extinction vortex and the ethics of breeding and consultation…

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

Our Changing World takes a deep dive into controversial plans by US company Colossal Biosciences, backed by filmmaker Peter Jackson, to de-extinct the Moa. In part one of a two-part series, Sharon Brettkelly looks at whether it CAN be done.

Sign up to the Our Changing World monthly newsletter for episode backstories, science analysis and more.

LEARN MORE:

• Colossal Biosciences claims they have de-extincted the dire wolf, from CNN.
• More detail on Colossal Biosciences’ artificial egg.
• Listen to Kathryn Ryan speaking with ‘Mr Moa’ - paleozoologist Trevor Worthy about his long career.
• Auckland Museum research associate Daniel Thomas talks to Tuwhenuaroa Natanahira about the discovery of million year old moa footprints.

GUESTS:

• Dr Andrew Pask, Chief Biology Officer, Colossal Biosciences
• Associate Professor Nic Rawlence, Director of Otago Palaeogenetics Laboratory, University of Otago.

IN THIS EPISODE:

(00:00) Could we bring the moa back?

(02:30) Sequencing the moa genome

(06:00) DNA data

(08:00) The artificial egg breakthrough

(10:20) How a "moa" would actually be created

(12:30) Critics challenge the science

(17:20) The conservation implications

(22:00) Māori consultation questions

(23:51) Will we ever see moa roaming again?

(26:08) Coming up in Part 2

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

Cold plunges and cold water swimming are increasingly popular, with big benefit claims being made on social media. But is submerging yourself in frigid water actually good for you? Claire Concannon joins a team of researchers at the 2026 New Zealand and Oceania Ice Swimming Championships in Alexandra as they try to get some better data about both the risks and potential benefits.

Sign up to the Our Changing World monthly newsletter for episode backstories, science analysis and more.

IN THIS EPISODE:

(00:00) Introduction – the rise of cold water swimming.

(01:06) The 2026 New Zealand and Oceania Ice Swimming Championships in Alexandra.

(02:00) Competitor Susan Sherwen on why she ice swims.

(05:10) How researchers track swimmers’ core temperature, stroke rate and perceptions of cold.

(07:30) Prof Jim Cotter on cold shock, hypothermia and afterdrop.

(12:00) The recovery room – Steven and Susan after their swim.

(17:30) Potential benefits and what the research says.

(20:30) Blood samples and looking for brain health proteins.

(23:40) Potential mental health benefits…

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