In order to save the perilously endangered rhinoceros, sales of its horns should be legalized, four leading environmental scientists said Thursday in the influential journal "Science."

"As committed environmentalists we don't like the idea of a legal trade any more than does the average member of the concerned public," wrote lead author Duan Biggs of the ARC Centre of Excellence for Environmental Decisions (CEED) and University of Queensland.

"But we can see that we need to do something radically different to conserve Africa's rhino," he said.

Although there is a global ban on killing rhinoceroses and selling their horns, there is a fierce demand, mainly attributed to Asian consumers who use the ground up horn for traditional Chinese medicines.

Attempts to discourage the use of rhino horn have failed, the scientists said, and, without a legal avenue to obtain the ingredient, the black market has stepped in.

"Rhino horn is now worth more than gold," the scientists noted, saying that a kilogram that cost $4,700 in 1993 would fetch around $65,000 in 2012.

Poachers, enticed by the high price tag, have swarmed, and "poaching in South Africa has, on average, more than doubled each year over the past 5 years."

That has had a devastating impact on the already endangered species: the Western Black Rhino went extinct in 2011, and just 5,000 Black Rhinos and 20,000 White Rhinos remain.

But the scientists said the demand for rhino horn could be satisfied while keeping rhinoceros populations safe -- by harvesting horns from rhinos who have died of natural causes or humanely shaving the horns of living animals.

In addition, "rhino farms" would require setting aside more savannah land, which would help conserve other species, and would provide a legal source of revenue for impoverished rural communities in southern Africa.

They liken their proposal to the legal trade in farmed crocodile skins, which has saved the endangered reptiles from over-hunting.

A similar proposal for the rhinoceros was rejected 20 years ago, but the scientists said now is the time to reconsider, at an upcoming conference on the convention that governs the international trade of endangered species (CITES).