[AnimalMuppet]

It seems clear that, with the same level of technology, more people put more load on the environment than fewer people do. The question then becomes, are we currently putting "too much" load on the environment? I think that's where the dispute lies.

And since there is no clear definition of "too much", there is no provably correct answer to the question. One person looks around, sees what's happening to the oceans, the carbon dioxide level, and so on, and says "Of course it's too much!". Another looks around, sees things "pretty much the same as before", and says "clearly not too much".