Those transitions have also been heavily dependent on the energy infrastructure that came before. The age of steam was not possible without human and animal work to mine the coal and build the machines. Even now, the wind turbines we look to to help us escape fossil fuels are steel towers (you make steel in coal-fired blast furnaces) topped by plastic blades (which comes from petroleum), installed by (gasoline-powered) construction equipment. A wind turbine is a “pure expression of fossil fuels,” said Smil during a 2013 lecture at the Perimeter Institute.
So, while Smil agrees with pretty much everyone else that the next big energy transition is from nonrenewable to renewable resources, he is cautious about the timing. At one level, the change is plainly inevitable. There will come a time when non-renewable resources run out, and Smil says it will be advantageous to transition off of fossil fuels long before then, to avoid climate change.
In this, Smil is no different from countless energy advocates from Greenpeace to Al Gore to T. Boone Pickens. Where he does differ is in his opinion about how quickly it can happen. Where Gore calls for a complete conversion to renewables in 10 years, Smil thinks the transition will take generations.