OK, great. But if we stick to oil for those 100 years, we'll continue killing planetary biodiversity, which will cause unknown knock-on effects that will make it hard to grow food the normal way, even if we're only looking at effects on humans. Is that really a good way to live?
Saying that the current situation is imperfect is like saying that jumping off a bridge puts you in a situation that isn't ideal. We need to pull our collective heads out of our collective asses and start investing in alternative energy sources - now, not in 10 or 20 or 50 years.