For a group of youngsters attending the UN climate talks in Copenhagen, age makes all the difference in saving the planet.

Sporting bright orange T-shirts emblazoned with the slogan "How old will you be in 2050?", the youths sought to remind delegates who will still be around in some 40 years that the decisions they make today will affect the world they live in then.

Delegates who looked as if they would survive to 2050 were given one of the orange T-shirts, while others were given a scarf of the same colour at the entrance to the Bella Centre conference hall where the climate negotiations are being held.

"Are you ready to say that survival is non-negotiable?" members of the group asked each delegate as they passed through the security check, awaiting an answer before handing over their gift.

Organised together with the United Nations Framework Convention on Climate Change, the "Young and Future Generations Day" was to be marked by a series of demonstrations by more than 1,000 young people from 100 countries.