Satish Kumar has been a pilgrim of positive change for over 50 years. He’s best known for his 8,000 mile ‘peace walk’ in the 1960’s, from India to the four nuclear capitals of the world. He shares his experience helps us know the difference between a desire of the mind and a true calling. And this year marks the 10th Anniversary of Earth Hour, a grassroots campaign which began in Sydney and is now a global phenomenon. We hear from Australian Earth Hour Ambassador, Zoe Gameau.