Earlier quoted context omitted.
You mean, it is not a problem because the planet can support that many? Or do you mean it is a problem, but it will solve itself? I don't think either is correct. The first is only true today because non-First World inhabitants are living on a much smaller ecological footprint than Europe and the US. However, that footprint is increasing rapidly. The second reading at least acknowledges there is a problem, but I thin…
Historically, all such "carrying capacity" estimates have been shown wrong. What makes you believe the 7.7 one is any better?
Quite frankly, it doesn't matter to me whether the "real" capacity is 1 billion or 20 billion or 100 billion, as I don't believe we (as a species) have any chance of moderation in the face of opulence. As long as there's any surplus capacity left on this planet, we will find a way to use it. As fast and as wasteful as we can, until it all comes crashing down.