The current rate of extinction is between 100 and 1,000 times higher than the pre-human background rate of extinction. What we're going through will be an extinction event on a timescale and severity that will be closer to the Permian or Cretaceous extinction, which resulted in the species death of 95% and 78% respectively, and caused by apocalyptic scenarios; meteors and volcanos effectively suffocating the planet. Never before has a single species been responsible for such destruction on Earth.
I suspect humanity will survive whatever future is yet to come. I just hope we managed to preserve a substantial percentage of natural diversity through that process.
This also makes it harder for many species to adjust to climate change and habitat loss as it is much harder for them to migrate.
Ocean biodiversity loss is almost certainly harmed by overfishing and toxic run-off from rivers/lakes don't get me wrong, but it's also hugely impacted by rising sea temperatures. Ocean biodiversity increases exponentially with sea surface temperature up to about 20-25 C (68-77 F). Beyond that threshold, biodiversity drops off due to the limits of aerobic metabolism. Temperatures that make it hard for cold-blooded sea creatures to breathe have likely been among the biggest drivers for shifts in the distribution of marine biodiversity.
Desertification, caused partly by human agriculture and the removal of soil-retaining plant matter but mostly due to climate change, is also a major cause of species loss and it's occurring across much of the planet - especially Africa and Central Asia. Those animals that can't rapidly migrate to cooler/wetter climates are ripe for extinction.
To me this is the much bigger issue than us humans adapting. For us to adapt it demands a lot of labour, and associated costs, it will make life harder but it's doable.
Nature doesn't have this ability, animals can't get together in an assembly and find technological fixes to support them living in their environment when it changes, they either move to another area where they are adapted to (if it exists) or they die.