Four southern African nations are considering breaking away from the United Nations’ Convention on International Trade in Endangered Species to set up a parallel organization to allow trade in ivory.

Tourism ministers from Zimbabwe, Namibia, Zambia and Botswana met on Friday to look at alternate strategies to CITES, Mangaliso Ndlovu, Zimbabwe’s environment and tourism minister, said by phone.

Those countries are home to more than half of the world’s African elephants and have urged the global organization to end a ban on trade in tusks, as it seeks to deal with over-population of the animals.

“We discussed the possible establishment of something like the Kimberley Process,” he said. “The idea is for checks and balances and for that people to operate within the correct parameters.”

Set up in 2003, the Kimberley Process is an organization of companies and governments that aims to prevent the trade in conflict diamonds. Member states must certify that the proceeds of diamond shipments won’t be used to finance conflicts and commit to transparent practices, according to its website.

Aerial Census

Still, legal trade in ivory outside the countries could face opposition from other members of CITES, which include China, where much of the world’s ivory from poached elephants is smuggled to.

The countries plan to conduct an aerial census of the elephant populations in the Kavango-Zambezi Transfrontier Conservation Area, which spans the four nations as well as part of Angola. The survey has secured $1.5 million in funding, which means work can start immediately, Ndlovu said. Some 220,000 elephants are estimated to live there.

Botswana and Zimbabwe, which boast the world’s two biggest elephant populations, have said there are too many of the animals and they are becoming a danger to farmers, destroying crops and damaging habitats.