COP 28, the largest climate summit in history, has drawn to a close. Marnie Chesterton examines some of the main stories to emerge from this lengthy conference.

The way we look after our oceans, measures needed to ensure food security and an agreement to transition away from fossil fuel dependence were some of the big themes of the summit.

The BBC’s climate reporter Georgina Rannard takes us through the final agreement.

We hear from Glada Lahn, senior research fellow at international affairs think-tank Chatham House, who explains how we might one day wean ourselves off so-called ‘brown energy’.

Farming is also a source of greenhouse gases. Growing, processing and packaging food account for a third of all greenhouse gas emissions. How we feed the 8.1 billion of us on the planet continues to be a contentious issue. Casper Chater from Royal Botanic Gardens Kew explains what we can do to adapt our existing crops to cope with more frequent flood and drought events.

Oceans are warming, losing oxygen and acidifying. Sea levels are rising. We speak to Ko Barrett, a senior climate advisor at the US's National Oceanic and Atmospheric Administration, about the role oceans have played so far in helping us mitigate the worse effects of climate change. And we meet Mervina Paueli, a 25-year-old Tuvaluan negotiator, whose small archipelago in the South Pacific is on the frontline.

Presenter: Marnie Chesterton Producers: Louise Orchard, Hannah Robins and Harrison Lewis Editor: Richard Collings Production Co-ordinator: Jana Bennett-Holesworth 

BBC Inside Science is produced in collaboration with the Open University.

143: System Overhaul