Vampire Diaries star Ian Somerhalder and Bollywood actor Rahul Bose have been named Goodwill Ambassadors for this year's World Environment Day Challenge led by the United Nations Environment Programme (UNEP).

They join Gisele Bündchen and Don Cheadle in encouraging people throughout the world to take part in an environmental activity on June 5, and break the record for the most activities registered in WED's four decade history.