You're right in that our atmosphere will not soon "prevent the planet from cooling and from having liquid water on its surface." In other words, yeah, we aren't going to literally boil the oceans. We shouldn't throw around the term "runaway greenhouse" in serious discussions of anthropogenic global warming.

However, reality is somewhere between "doomsday cult nonsense" and the flippant, dismissive tone of your comment that characterizes the worsening climate crisis about which our species is not doing enough as "minor/major climate changes." That's definitely understating the costs and disruptions that human civilization is facing on its current course.

I wonder if OP was referring to any of the more immediately concerning positive feedback loops: https://en.wikipedia.org/wiki/Climate_change_feedback#Positi...