There is no known natural cycle in which the rate of change in global temperature matches what's been happening in the past few decades. Current and even projected temperatures are well within the range of what happens naturally, but it's happening much faster than it ever has before. This has worrying implications for the ability of ecosystems to adapt, and more importantly for us humans, for the ability of civilization to adapt. Civilizations have collapsed due to slower, smaller changes than this.

You say "I really doubt we humans can affect climate changes in any way." This is a common sentiment. I see a lot of people saying things like this. "The Earth is just too big." "Humans are insignificant." And so forth. What causes you to say this? Have you actually run the numbers? I've not found anyone expressing that sentiment who actually has anything like a quantitative basis for it.