What a privilege it is to do the job I do. Yes, it can be frustrating - when climate change science doesn't seem to result in rapid responses at an intergovernmental level the ranting can quickly start - but boy can it be rewarding too.

Yesterday I was down in London to give evidence to the House of Commons Environment Committee on how the government might do more to stimulate climate change mitigation at the level of individuals. This was quite an experience in itself, the closest (I dearly hope) that I'll ever have to come to being on trial. What made the day really special though was one man, and what a man. Giving evidence to the same committee was Sir David Attenborough.  You could have heard a pin drop as the committee members, audience and journalists listened to his evidence. I can think of only one other person who I've seen engender such an atmosphere of calm and respect, and that was Nelson Mandela.

Earlier this year I had the great fortune to work with David Attenborough on the BBC's Climate Chaos films. These films marked the public recognition by him that human-induced climate change was real and dangerous. He explained yesterday how, at a seminar given by the climate scientist Ralph Cicerone, he became convinced of the problem and its monumental scale. Throughout most of my life David Attenborough has been both an inspiration and a trusted guide through the ecosystems of the world. In many millions of front rooms he has opened up windows on corners of the planet we couldn't have dreamed of seeing, species and behaviours that leave one open-mouthed with wonder.

Right now he is working on his new series 'Life in Cold Blood' and on a set of new climate change films for the BBC. His body of work just goes on growing and as to the quality, well, he and the BBC's Natural History Unit are the definition of 'blue chip' programme making. If any single person can provide the step change in public awareness of human-induced climate change that is required, then David is that person.