What I meant, of course, is that the number of world population is absolutely oversized with respect to the number of resources.
That isn't a definitive truth though, just an opinion. Plenty of people would say, with equal justification, that the problem is unequal distribution of the resources and that the current human population could all live perfectly comfortable if that could be resolved.
The specifics of that example don't really matter, the general point remains that there isn't a singular simple answer than can be deemed the "truth". Very little (if anything) is simple enough for that to be the case.
I believe there are objective truths.
You
believe. You don't
know that as an objective truth.
There are clearly a whole load of definitive facts about the universe. The problem is that we can't know exactly what those facts are. We can observe, test, believe, conclude and, in many cases, reach 99.9% certainty on some things (or at least a high enough level for practical day-to-day purposes) but never with 100% certainty. There are plenty of things people once generally agreed was objectively true that turned out not to be (or, more commonly, turned out not to be a simple as first imagined).
Those "truths" we hold to aren't necessarily consistent with the actual facts, nor with the "truths" as held by other people. That is actually the reason that the principle your thread highlights is so important; We need to speak our "truths" not because they must be right, but because they could be wrong.