I never knew that. How much hemp is needed to be grown to support the number of cars on the road we have today? Was it something in line with ethanol or more like plant based diesel?
The problem with hemp is the same as the problem with corn for ethanol. High water use is expensive.
Forgot to add, putting millions of acres to work growing hemp lowers the supply of whatever is currently being grown on those acres.
That affects food prices. We don’t have unlimited land or water.
I do know the plant was criminalized and demonized shortly thereafter. It didn't fit Lucy's plans for murder and mayhem for mankind.