True, but as a society we certainly don't act like we care at all about biodiversity.

The thing is though, this is not likely what will happen. It will temporarily crowd out existing vegetation, which will create the conditions for new species to arise. By bringing more carbon into the soil, it will increasing fertility and with that, new forms of life can take place and in turn crowd out the pioneering 'weed', increasing rather than diminishing biodiversity.

Certainly some species will be lost. This is called succession. But others will take their place. I'm not sure if Arizona will have the climatic conditions to move far beyond a desert, but that is what is happening and what we would be preventing.

That process takes a very long time, much longer than it takes for things that exist today to go extinct

When grass evolved it took over the world, killing innumerable species, and decimating ecosystems.

This weed may suck and maybe we want to keep it out of the desert for various reasons... but it shouldn't be dressed up as some kind of nature-preserving virtue. It's just bio-engineering to keep the ecosystem how we want it.

Oh never mind, I guess mass extinction is fine then.

Indeed it is. Every biological renaissance in known history was preceded by a mass extinction event.

If something has happened in the past, that means it’s good and we should do nothing to prevent it from happening again. Indeed, if we ourselves are the main reason it’s happening this time, that’s fine too, since it’s happened before.

It is important when ironically agreeing with someone that the pseudo-agreement expresses your supposed shortcomings.

Otherwise you’re just legitimately agreeing, but snarkily (and weakly).

Hey if you want to wholeheartedly embrace a worldview so nihilistic it doesn't have an answer for why we should try and stop people from doing mass murder, go nuts.

Ah. The non-sequitur approach to debate. Charming.

If you can’t see the difference between allowing a plant to naturally spread and mass murder, I pray for those around you.

You were saying that mass extinction was no big deal, not “allowing a plant to spread,” and the reasoning you apparently embrace would in fact lead to that exact absurd result, so it is not a non sequitur.