An “on-air video exhibition” focusing on environmental issues will be broadcast globally next month, with contributions from key “green” artists such as Olafur Eliasson, Isabelle Hayeur and Markus Hoffmann. The web stream, Art Speaks Out, will run for 24 hours from 6pm on 5 December, on ikono.tv. The one-day viewing marathon will be split into five sections: contemplation, concern, anxiety, fear and hope (independent curator Kathy Rae Huffman will present part of the “anxiety” strand). The global digital event, which features more than 60 international artists, is part of ArtCop21, the cultural programme of the UN Climate Change Conference in Paris (30 November-11 December).