Parasitism, in the words of Wikipedia: "a non-mutual symbiotic relationship between species, where one species, the parasite, benefits at the expense of the other, the host."
By this definition, humans neither are nor aren't parasites, since our activities are enormously diverse, and some of them benefit our host (the biosphere) while others very definitely don't. I think it's fair to say that, over time, our activities have become less and less beneficial for the planet. But I think it's only correct to use the term "parasite" as an analogy, since in the literal sense the situation is much more complicated than that.
But, even as an analogy, natural disasters being the planet's "immune system" hardly works. They're apples and oranges. I dunno — I mean, rhetorically, it's a powerful move to compare the two. But the way the question is phrased makes it sound like you want to know if natural disasters are literally a planetary immune system. I don't think that's supportable, no.
what do you think are we?
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