the fact that losing an entire species forever is an extremely sad thing to happen
Extremely sad! Remember guys, losing an entire species is entirely IRREVERSIBLE! There is no undo if we fail to act on biodiversity! One day, maybe millions of years from now, the earth's climate will be back to normal cycling. If we destroy the biodiversity, we can NEVER EVER get that biodiversity back. New species originate at an extremely slow background rate, a rate which has been decreasing since the Cambrian (the time of the Burgess Shall fauna). True, mass extinctions are generally followed by a burst of recovery, but there is also usually a delay of millions of years (see stuff by Dave Bottjer, Peter Ward, Doug Erwin...).