This mass extinction caused by humans is an order of magnitude faster and affects far more varity of species and plants.
Furthermore, even if the pace and breadth of current extinction were that dramatic, isn't the argument against that a purely emotional one? I sincerely doubt that most humans can even name a hundred species; would they really miss a few million if a few million others remained?
Just to be clear again: I'm not arguing against conservationism, I'm interested in the arguments being made for it. I believe we are conserving for own selfish purposes, and I'm perfectly OK with that. I just think it's wrong to call that "natural".
[1] https://en.wikipedia.org/wiki/Permian%E2%80%93Triassic_extin...
Nothing. But you can say that about asteroids that kill the planet as well.
That's basically nihilism. Many people want to live and enjoy nature, that's why. We just got conflicting interests of short-term thinking that resembles nihilism (Nothing matters - let's live life to the fullest) and long-term thinking / delayed gratification (I want my kids / all the animals / the next generation to have a nice life as well).
edit: for the semantics of "natural" - humans can be seen as a part of nature. It's just intellectual gymnastics if one defines us as natural or not. Some say humans aren't natural and have good reasons for it, some say they are and have good reasons for that. This discussion really isn't that meaningful. Many peole say we have responsibility because we have consciousness, but even that could be argued. It all depends on what you believe.
If you extrapolate the speed of current devastation, extinction and let it play out over the time-span of the last mass-extinction, there really wont be anything living on earth besides micro-organisms.
Non-selfish arguments for why we should not kill off other species? Why should we not kill all life bigger than a pea on earth? Ill let you take that one.
There are medicinal and practical uses for plants, and some are have only recently been discovered. Losing them is losing this these potential discoveries and uses.
Humans inherently enjoy nature. We like to see trees, greenery , wildlife. The loss of these things hurts our enjoyment of the world.