Justin spoke to the Holocaust Centre of New Zealand's chair Deb Hart about International Holocaust Remembrance Day.

He also talked to the Rotary Tree's Trust chair Russ Ballard about their North Shore tree-planting project being mowed down.

Producer Joe chatted to the University of Auckland's Karen Waldie on the relation between pre and post natal depression and mental health.

He also talked to Ruth McManus of Canterbury University on green burials.