The world's oceans have absorbed huge quantities of carbon dioxide, protecting us from the worst effects of climate change, but how much longer can they defend us? Join Helen Czerski in New Orleans at the world's biggest conference of marine science to meet the experts working to keep the ocean working for us.Tom and Helen's guests from the American Geophysical Union conference include Jeremy Werdell of NASA and Jaime Palter of Rhode Island University.With special thanks to the team at the AGU and David Mann of Loggerhead Instruments.Produced by Alasdair Cross for BBC Audio Bristol in conjunction with the Open University