People in Britain rate committed campaigners such as Nelson Mandela and Martin Luther King far more highly than celebrities such as Sir Bob Geldof and Angelina Jolie, a recent YouGov poll commissioned by Christian Aid shows.

Saving the environment is a serious business – but you can still have a laugh doing it. That’s the message of UK development agency Christian Aid in launching a couple of hilarious YouTube videos aimed at getting people to take up the eco-challenge with a smile on their faces.