Since China is going gung-ho over building cities for its ever increasing urban population, why don't they also build artificial islands as well? For example, they could construct just 1000 islands around its eastern coastline. Furthermore, if each of these islands has a residential population of 100 thousand people, that means all 1000 islands could house 100 million people. Now, I understand that China has a total population of 1.3 billion people. Nevertheless, the 1000 islands holding 100 million people does reduce the amount of strain being cast upon cities being built on the mainland; even if it's only temporary.