Does smoking cause emphysema?

Definately. Smoking is the number one risk factor for the development of emphysema. Other risks include family history, a genetic predisposition (such as Alpha one antitrypsin deficiency) and occupational exposure (usually related to dusts). If you have no desire to develop emphysema do not smoke.
Yes. Tobacco smoking is the number 1 cause of emphysema in the western world, and is well on its way to becoming that in the developing world, because of all the cigarettes we sell them. It is not the only cause, and air pollution, hereditary deficiency of an enzyme called alpha-1-antitrypsin, and other conditions can cause it, but over 90% of cases are from tobacco smoking, including second-hand smoke.