I was told I should move this thread from the ASB forum.
What if the tobacco plant went extinct in pre-Columbian America? Tobacco farming was crucial to the plantation economy of Virginia. Without it the early English colonies would have been less profitable and their expansion would have been retarded. This too, would lead to less confrontaion with the Indians and perhaps later introduction of slavery to the colonies.
Tobacco had major effect on world history being the essential component of opium smoking. Although opium was used for medical purposes for centuries, it was the mixing with tobacco that made it smokable and transformed it into a hugely profitable trade commodity. Without opium, the British colonies in India would have been less profitable. The East India company would generate less income for the crown and be less influencial. The Opium Wars with China would not happen, and 19th century China would be much more stable.
It was the oversupply of opium production that lead to the mass production of morphine, another great addiction of the 19th century. And perhaps heroine addiction too would be less of a factor. Butterfly effects on the drug culture as a whole.
Of course there is also no health problems caused by tobacco smoking. Much less lung cancer, oral cancer, erectile dysfunctions, longer life expectancy, and so on.