Assuming (for the sake of argument) 50 years is accurate, we could practically stretch it all the way to +100 years with some minor adjustments.

I think the biggest problem is the ease of consuming fossil resources just because it's available right now in pretty much any quantity. It lowers the main incentive to actually dig through all this to find ways to limit use of fossil resources, but without losing productivity and thus billions in revenue and profits.

Most people in today's world live in the here and now, where every potential obstacle in the next couple of years is something they prefer to deal with by that time instead of now. This mentality is quite damaging and doesn't really make much sense to me, but then again, we're just small fishes. The main players have all the incentive to sell you dirty fossil resources in the here and now.