Stuck on a ledge halfway up a 3,000-foot cliff in Oman, his climbing rope sliced in two by sharp rocks, Jimmy Chin did what anyone else would have done in his predicament.

He took a selfie.

“I had some time to figure out what I was going to do,” said Chin, a National Geographic photographer whose images of extreme climbing by the Straits of Hormuz appear in the magazine’s January issue.

“That’s when I took the selfie,” he told AFP. “It was one of those moments when, ‘Well, I’m a Nat Geo photographer’. I had to document (the moment). It was pretty classic.”

Self-portraiture has been around for centuries, but the global proliferation of smartphones with built-in digital cameras — plus the ability to share photos instantly on social media — has taken the genre to a new level.

With 2013 coming to a close, the publishers of the hallowed Oxford English Dictionary, arguably the final authority in anglophone lexicography, declared selfie to be their “word of the year.”

“Selfie: noun, informal. A photograph that one has taken of oneself, typically one taken with a smartphone or webcam and uploaded to a social media website,” according to Oxford. “Also: selfy. Plural: selfies.”

Internet search provider Yahoo meanwhile estimates that in 2014, about 880 billion photographs will be taken. That’s 123 photos for every man, woman and child on Earth. Many will be selfies.

In Britain, a survey for Samsung found that 17 percent of men, and 10 percent of women, take selfies because “they enjoy taking good-looking photos of themselves.”

“I think ‘selfie’ is a term of endearment for the self, in a way,” said Sarah Kennel, curator of photography at the National Gallery of Art in Washington, who admits to taking the odd selfie herself.

“It does reflect a kind of narcissism in our culture,” she told AFP.

US President Barack Obama and British Prime Minister David Cameron got tongues wagging when they took a selfie with Danish leader Helle Thorning Schmidt at Nelson Mandela’s memorial service in South Africa.