We are committing a mass extinction on Earth's life, there will be a geological record one day of where life suddenly fell off.
And what's really wild to think about is that while tragic to us and our perspective of the beauty of the world... in the larger picture, it will still be utterly insignificant to Earth's history. The next million years will see massive portions of life die off, climates will change, new species will emerge and grow into new ecosystems, and there will be an entirely new set of fauna and flora, and humans will be a distant memory, a rust-colored line on the strata.
And that coming million years? Also a blink of an eye in Earth's history. A fraction of a fraction of our planet's history of life's abundance and drama. All the life we see around us represents a sliver of a fraction of a fraction of Earth's biological history. It's so, SO much bigger than any of us can imagine and it should have the effect of humbling us.