As a Unicef Ambassador, I have had the privilege of travelling the world to witness the amazing work they do. I have seen some of the most heart-breaking sights you can imagine; heard some of the most devastating stories it is possible to hear. Many of them from the mouths of children so young, they have only just learned to speak at all. To say that it's humbling doesn't even begin to describe it.
When in Lebanon, I remember sitting with an eight-year-old Syrian girl whose home was just a few plastic sheets held up by a handful of sticks. I listened to her tell her story about her journey out of a country that has turned into Hell. A journey where she has seen things many only see in horror films - torture, rape, all manner of atrocities and unspeakable horrors; a journey that's included the loss of her mother and her sister; a journey that her father didn't even begin because he didn't make it out of the hell that this small, unimaginably brave eight-year-old girl has somehow survived.
Sitting there, this small, unimaginably brave eight-year-old girl, tells me her name is Rose and I think of my own daughter also named after a flower . As a father all I want is for her to be safe and happy. Everyone wants these things for their children, yet Rose, along with all the other children I saw in Lebanon, running barefoot through mud and sewage, are simply not afforded this right.
When Rose finished telling me her story, I remember not knowing what to say. What can someone who has a life of such privilege and comfort and opportunity say to a little girl who has experienced such horrors and such hardship at just eight years old? What words of advice or adult wisdom could possibly apply or be sufficient?
All I could do was listen, not turn away and make a promise. It's the same promise I've made everywhere that I've seen Unicef's work. From children in Chad picking grains of rice out of cracks in the earth, to children who have suffered the most unbelievable horrors as child soldiers in N'Djamena and who have been forced to perpetrate those same horrors upon others.
It's a promise that I will go home and tell people what I have seen. That I will tell their stories.
So that's what I'm doing, telling their stories and those of the people who are helping them, of Unicef's, amazing, extraordinary work.
Unicef is there for children. Wherever and whenever children are in danger, no matter the politics or the difficulties, Unicef is bringing children a chance for safety, protection from violence and exploitation, a chance to play, clean water to prevent disease and warm clothes to endure the harshness of winter.
Today we are facing the greatest humanitarian crisis since the Second World War. There are more than two million children who have been made refugees as a result of the ongoing conflict in Syria.
That's two million stories of children like Rose.
And their lives matter - because if those children's lives don't matter then how can my child's life matter. If those children aren't important then my child can't be important.
Either every child's life matters or none of them do.
So in sharing their stories, I'm also asking you to take notice and to do something about this.
We have to step up to this humanitarian crisis and we have to act. The lives of millions of Syrian children have been turned upside down and it is not enough to be shocked. Shock must be matched by action.
Unicef is one of the few organisations working inside Syria, as well as delivering aid across the region and from now until the end of January the UK government has promised once again to match pound for pound everything that you donate.
We need to do something about this, and through Unicef you can.
In an increasingly dangerous world, protecting children in emergencies is life-saving and must be prioritised -we all have a responsibility to make sure this happens.
All images copyright UnicefSuggest a correction