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