China's promise to shut down its commercial ivory trade by the end of the year is good news for Africa's elephants. For the Chinese government, though, it creates a strange problem: what to do with its 40-ton stockpile of ivory, worth about $150 million. Although that may not sound like a lot, how China approaches that hoard may be almost as consequential for conservation as the ban on trade.

Nowhere is demand for ivory higher than in China, where it's been used in handicrafts for thousands of years. Much of the trade is regulated, with the government occasionally allowing imports of seized and stockpiled ivory that is sold through a network of authorized workshops and dealers. Collectively, government and legal private stockpiles are now estimated to be worth about $600 million. Black market supplies, which are sometimes laundered through the official system, may be much larger.

With the ban on trade imminent, though, China is left with two imperfect choices for its ivory.