ruggiero: the problem begins very simply with demand. narrator: and china drives the demand for ivory. knights: china now is estimated to be 70% of the world's ivory market. there is a tradition of ivory carving, but also, of course, the massive growth of the chinese economy. narrator: around 300 million people make up china's middle class today. that's more than the population of the united states, and they are looking to spend their money on luxury goods. ivory has particular appeal because of its long history in china. it has been carved there for more than 2,000 years, expressing many core chinese cultural and traditional values. knights: i think in some cases, people are speculating that ivory is almost like a currency that they can invest in for the future. alie: you walk through beijing and in some of the stores you see ivory mantelpiece, exquisite carvings going for like 50,000 u.s. dollars, 60,000 u.s. dollars. ights: but in addition to that, you have things like chopsticks, bangles that people wear, small carved items. all thes