[peter_vukovic]

> To begin with, a planet can be "dirty" without any civilization. Most planets are.

They can also be clean. Look at Earth. Don't see an argument here. We are discussing whether civilization pollutes or not, not whether planets are inherently habitable or inhibitable.

> We have seen it is possible.

Where have we seen it possible?

[otikik]

I don't think you are in a position to have reasonable discussion so I choose to stop here. Have a good day sir.

[peter_vukovic]

Fair point. I was too dismissive in my earlier response, and I apologize. You raised strong and valid arguments. My perspective is shaped by a long pattern of historical collapses, but I’d truly welcome any examples or evidence that point to a different trajectory.