young people - well you cant - so many simply wouldn't be educated - which would deny the very structure of communism. Finding the jobs - there simply wouldn't be enough work for all those people - no matter what rate the economy grew at - even with current population china struggles to keep them all working - in the last year the Chinese government has been worried about the risk of social unrest as the global recession kicks in and people loose their jobs - even in china. Housing - china really struggles now with housing - in many areas your talking 5 people to a small house. In poorer areas many more. Communism - with 2.5bn people - there is bound to be a group of people in the country who disagree with the governments policies and start causing upset - it may be difficult to control large scale upheaval. Like i said - even now the Chinese government have their concerns - worries largely founded by the Tibetan upset a few months back. Environmentally - 2.5bn people would need power - even more coal fired power stations? I think so. Food - people need this - so farming on an even more intensive scale than now and more wide spread would have to take place - this could lead to large water pollution from fertiliser and pesticides - killing huge swaths on wildlife. Pollution from factories would be even greater as populations needed work and exports increased, plus internal demand for products. ]