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.

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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?

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

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