Pharrell Williams delivers 'happy' UN speechNew York, March 22 (AZINS) Singer Pharrell Williams, best known for his viral hit "Happy", addressed the UN General Assembly here on the 'International Day of Happiness' as he raised his voice on the dangers of climate change.

During his speech at the United Nations Headquarters on Friday, Williams urged the youth to help raise awareness of climate change, reports aceshowbiz.com.

“I'm staring at the future right now. Hello to the future," he said.

After greeting the young attendees, the Grammy winner stated: “Music brought me happiness. And when you find out what makes you happy - and it can be something as detailed as a long-term goal or it can be something as simple as the way I feel when my son smiles - you should know that happiness is your birthright."

"If you don't take care of your home, you don't have a life, so we have to now transition from climate change to climate action. We're in trouble but we can change,” he added.

A special "Happy" playlist, featuring a selection of songs picked by numerous stars like Britney Spears and John Legend, was played during the event.

Williams was joined by environmental activist Philippe Cousteau and oceanographer Sylvia Earle at the event. After his speech, the singer was mobbed by the students who were holding up their cellphones and cameras ready for photographs.

Also to celebrate the International Day of Happiness, Williams was given the honour to light up the Empire State Building in yellow.