In 2009, someone broke into the Climatic Research Unit of the University of East Anglia and stole emails. The material was distributed online - mainly on blogs linked to climate change sceptics. It was used to make the case that scientists were surreptitiously twisting the facts to exaggerate climate change. That was not the case. But before that became clear, events would take on a life of their own, sparking a global media storm.

This is a story that matters - firstly because it may have set back by years efforts to combat climate change. But also because it foretold a future in which emails would be stolen and weaponised and where information and social media would be used to cast doubt on science and expertise.

More than a decade on, as the UK hosts a new global climate summit - COP26 in Glasgow - the mystery of who was behind ‘Climategate’ remains.   

BBC Security Correspondent Gordon Corera goes on the trail of this ‘cyber cold case’, talking to the key players as well as police and spies, taking the listener on a journey to a place where climate change and information warfare met - with world-changing consequences.

Producer: Sally Abrahams

Credit: MSNBC News Live 25 November 2009 and NBC Nightly News, 4 December 2009