'Twenty years ago today my father and eight other Ogoni men were woken from their sleep and hanged in a prison yard in southern Nigeria. When the news filtered out, shock and outrage reverberated around the world...What I recall...was the slogan that caught on...to ensure that “his death must not be in vain”. So has anything changed?...Despite several aborted attempts to reconcile the victims and perpetrators, my father and the other men remain convicted criminals in Nigeria’s legal books...If my father were alive today he would be dismayed that Ogoniland still looks like the devastated region that spurred him to action...And yet the impression that nothing has changed is deceptive...the Ogoni’s claims of pollution against Shell have been vindicated...the Ogoni have registered landmark victories in court cases against Shell in New York and London...We may finally be arriving at a tipping point in the carbon economy, and perhaps one day my father’s story will be more than a footnote in that history.'