In Carlow, this year's Cruinniú na nÓg, Ireland's national day of free creativity for young people, has chosen the theme of "The Sky is Blue". It's inspired by Leighlinbridge County Carlow Scientist John Tyndall who figured out why the sky is blue and the effects of global warming. 

In so doing he changed the world for the better in many ways and the young people of Carlow creatively respond to that.