>Are humans "big enough" to have such a big effect on nature as a whole? This is the question that we have yet to answer for certain.
Yes. We have answer that pretty conclusively. Humans are capable of and have carried out global scale changes to the biosphere.
>What is indeed bizarre is to see people accusing humans of causing mass events that have happened for millions of years without human intervention.
Mass extinction events have not been happening continuously for millions of years. Perhaps that is the cause of your confusion.
Just because something can happen without human intervention doesn't mean humans can't cause it. Trees can fall in the wind, but you would have to be a rather special person to argue that because trees can fall in the wind that it's impossible for a human to cut down a tree (humans being so much smaller than trees).
Yes. We have answer that pretty conclusively. Humans are capable of and have carried out global scale changes to the biosphere.
>What is indeed bizarre is to see people accusing humans of causing mass events that have happened for millions of years without human intervention.
Mass extinction events have not been happening continuously for millions of years. Perhaps that is the cause of your confusion.
Just because something can happen without human intervention doesn't mean humans can't cause it. Trees can fall in the wind, but you would have to be a rather special person to argue that because trees can fall in the wind that it's impossible for a human to cut down a tree (humans being so much smaller than trees).