I don't want to jump on the bandwagon too much, but I think if you want to argue for decreased energy use you have to do it in a way that has a vision for quality of life improving. You might for example point out how much more efficient cities are, or how wasteful consumerism is and argue that people can grow to love having less. I'm not sure, but you definitely shouldn't basically say the only solution is to keep the developing world down and maybe shrink the pie in the developed world too. That just isn't a realistic option.

Also like the other commenters I'm not at all sure renewables can't do the job. Prices have fallen fast