Thousands of students expected to protest over climate

Thousands of students are expected to strike over climate change today, in a move which is not supported by the Secondary Principals' Association. President Michael Williams says many principals have concerns for the safety of students - but there are schools taking a supportive approach. Cathy Ewing is principal of Nelson College for Girls and Melanie Webber teaches at Western Springs College in Auckland. They speak to Guyon Espiner.