[gbog]

Here on HN we need to back such affirmations with data. The bolder the affirmations, the more solid the data-backed proof need to be.

If we were to exchange "philosophical" considerations here, I'd tell you that sunday fishermen have complained weekly that there was much more fish in the river before since the dawn of humanity. I'd also tell you that my own home in downtown Beijing has seen a slug invasion this year, and that these animals are not disappearing at all (at least in my courtyard).

[JoeAltmaier]

That's a symptom of ecological upset too. One species flourishing when another dies off, and the resulting wild cycles. Not a good sign.

[gerbilly]

Here's a good article on that topic:

Planet of weeds Tallying the losses of Earth’s animals and plants By David Quammen/Harpers Magazine

http://courses.botany.wisc.edu/botany_422/readings/Quammen19...

[soundwave106]

Googling, a lot of the articles on species decline seem to point to the World Wildlife Foundation and The Living Planet, a survey published as a joint collaboration between the WWF and the Institute of Zoology.

Obviously, there is probably some bias due to this being in part from a conservation advocacy group. However, the methodology does appear to be documented in a peer-reviewed paper [2]. So I'd personally give it a fair more weight than mere anecdote.

[1] https://www.worldwildlife.org/pages/living-planet-report-201... [2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1569448/