WWF-Cymru, the Welsh arm of the global conservation organisation, is celebrating the 10th anniversary of Earth Hour (the annual event that sees millions worldwide switch off their lights) this March, by helping the people of Wales to send a giant, eight metre message in a bottle to Welsh politicians and the world, calling for urgent national and global action on climate change. Suspended from the Senedd building in the week running up to Earth Hour (March 25th, 8.30pm – 9.30pm)…