The United Nations has proved that it has got a sense of humour, even when it comes to climate issues. It appointed Red from the mobile game Angry Birds as its envoy "to inspire climate action toward a sustainable and happier future for all".

The lead character in the game was selected as Honorary Ambassador for Green for International Day of Happiness which is being celebrated on 20 March.

Speaking at the launch event on 18 March at the UN Headquarters in New York, Secretary-General Ban Ki-moon said, "The Angry Birds have entertained millions of people around the world – and now they are part of making the world a better place.

"We are proud to give Red a reason to go Green. There is no better way to mark the International Day of Happiness than to have our animated ambassador raise awareness about the importance of addressing climate change to create a safer, more sustainable and happier future for all."

Jason Sudeikis, Josh Gad, and Maya Rudolph who voice characters for the upcoming Angry Bird film were also present at the event alongside the movie's producers, John Cohen and Catherine Winder, interacted with students and gave them a sneak preview of the campaign which is encouraging people to take action on climate change and share their photos on various platforms using the hashtag #AngryBirdsHappyPlanet.

UN Secretary-General Ban Ki-moon, who started the concept of Happiness Day in 2013 said that "at this time of grave injustices, devastating wars, mass displacement, grinding poverty and other man-made causes of suffering", the Day is a global chance to assert that "peace, well-being and joy deserve primacy".

"It is about more than individual contentment; it is an affirmation that we have a collective responsibility to humanity," he added. "The best way to celebrate this International Day of Happiness is by taking action to alleviate suffering."