Originally Posted by
Oberon
depends what you mean by less polluting methods. i do agree that the more efficient energy collection mechanisms played a (large) role in it, but probably not in the way you're saying.
coal itself has gotten much, much cleaner in the last ~50 years or so, to give you an example.
the transition to natural gas also helped considerably because natural gas does not pollute as much coal (even clean coal is 'dirtier' than natural gas)
theres also the idea that energy usage has become more efficient simply because technologies become more efficient as time passes by. you wont generate as much sulphur in a chemical plant today as you would've in 1960.