Corals protect humans and sustain 25% of all marine life. But reefs are under threat from climate change, and mass bleaching events mean that some scientists estimate they could disappear by 2100.

In this episode, Graihagh Jackson is joined by BBC CrowdScience presenter, Caroline Steel. We go to Puerto Rico to see how self-duplicating, carnivorous coral could be the solution. We also speak to the scientist who helped discover what was causing coral bleaching in the first place - back when climate change was commonly denied.

Guests: Dr Ove Hoegh-Guldberg, Professor of Marine Studies at the University of Queensland in Brisbane Dr Stacey Williams, Executive Director at the Institute for Socio Ecological Research

Presenters: Graihagh Jackson and Caroline Steel Producer: Octavia Woodward Production co-ordinator: Brenda Brown Editor: Simon Watts Sound Engineer: Tom Brignell

Got a climate question you’d like answered? E-mail the team: theclimatequestion@bbc.com