The world's last frankincense forests are under threat after prices soared in recent years thanks to the global appetite for essential oils, Somalia officials have warned.
Overharvesting has led to the trees dying off faster than new ones can grow, putting the ancient resin trade at risk.
"(Frankincense) is something that is literally given by God to humanity, so if we don't preserve it, if we don't take care of it, if we don't look after it, we will lose that," said Shukri Ismail, Somaliland's minister of environment and rural development.
The Cal Madow mountains, which rise from the Gulf of Aden in sheer cliff faces reaching over 8,000 feet, are part of Somaliland, an autonomous republic in Somalia's north west.
The frankincense trade is Somaliland's largest source of government revenue after livestock and livestock products, Mr Ismail said.
Harvesting frankincense is risky. The trees can grow high on cliff edges, shallow roots gripping bare rock slithering with venomous snakes. Harvesters often slip and tumble down canyon walls.
"Every year people either break both legs or die. Those casualties are so often," said harvester Musse Ismail Hassan, adding that he wished he had proper ropes and climbing gear.
"It's a very dangerous job, but we don't have any alternative."
Once the resin is collected, women sort the chunks by colour and size. The various classes of resin are shipped to Yemen, Saudi Arabia and eventually Europe and America.
Besides its use as incense, frankincense gum is distilled into oil for use in perfumes, skin lotions, medicine and chewing gum.
In the last six years, prices for raw frankincense have shot up from around US$1 per kilogram to $5-7, said Anjanette DeCarlo, an ecologist and director of Conserve Cal Madow, an environmental group.
The rise in demand is the result of stronger marketing in the essential oils industry, which labels frankincense as the King Of Essential Oils, Ms DeCarlo said.
The dwindling supply of high-quality resin, and competition between exporters, are also factors.
Now over-tapping is destroying the trees across the Cal Madow, as tappers try to extract as much sap as possible and make too many cuts per tree.
They also tap the trees year-round rather than seasonally, preventing the trees from recovering.
"The death rate of the adult trees is alarming," Ms DeCarlo said. "There is potential for regeneration, but it takes about 40 years or so for these trees to become viable for tapping if it's done right."
Ministers worry the ancient trade could disappear.
"Frankincense that the pharaohs were using came from here, so you could imagine it has a history, it has a rich history," Mr Ismail said.
"I'm afraid that we will lose that rich history."