In engineering, you use an operating envelope to understand systems. You understand where the limits are for a system and do not operate the system above those limits. Aircraft are a good example.
Can the earth support one trillion people? What is the earth’s operating envelope?
In the end, it doesn’t matter how ingenious humans are if they keep reproducing exponentially. The exponential growth from 1800 to today was made possible by human ingenuity. But where will you get the resources to support a trillion people?
Non-sequitur.
Of course there are limits to how many people the earth can support. So what?
As others have noted, no one expecting the earth's human population to keep expanding exponentially. In fact, most estimates are the earth's population will stabilize and decrease over the next hundred years.