The United Nations has found an unusual ally for its fight against climate change in Red, the grim-looking red bird from the mobile game Angry Birds.
The UN named Red its Honorary Ambassador for Green on Friday, which also marked International Happiness Day.
People around the world are asked to make Red happy by sharing photos of recycling, using water economically or promoting other sustainable practices.
"The Angry Birds have entertained millions of people around the world – and now they are part of making the world a better place," said UN Secretary General Ban Ki-moon.
"We are proud to give Red a reason to go Green."
Actors from the upcoming animated film The Angry Birds Movie were also present at United Nations headquarters for the launch of Red's campaign.
"He's sarcastic, a little cynical, definitely viewed as angry amongst his very, very happy bird peers, and so he's a little bit of an outsider," Jason Sudeikis, the actor playing Red's voice, told dpa.
Sudeikis said has had played Angry Birds on his smartphone, but not very often.