As John Schellnhuber, one of the biggest European climate scientists that has been part of the majority of IPCCs, said last year about COP:

“Wenn die Länder die Klimaziele nicht umsetzen, sind diese Konferenzen nur Jahrmärkte der Eitelkeit.”

Translation by Google:

“If countries do not implement the climate targets, these conferences will be nothing more than vanity fairs.”

Interview, where he said it, and also said that 3 degrees above pre industrial would mean the end of modern human civilization (in German):

Youtube