Adding renewable energy sources will not reduce total fossil fuel consumption world wide. There's not a limit on the amount of energy that people will use -- adding more renewable energy sources won't satiate our demand for energy and as long as fossil fuels are there, people will use them. Double, triple, quadruple, renewable energy production, and people will still burn fossil fuels as fast they can pull it out of the ground. The rollout of renewable will have to be accompanied by a ban on the use of fossil fuels to supplement them.