Yes some climate change happens in seconds from impact phenomena and some change comes slowly. The current change is in between.

The evidence of mammals as large as Mammoths being frozen solid in mid chew is dramatic. Ice merely cooberates other evidence.

Methane has over twice the detrimental greenhouse gas effect of CO2.
The scope of methane release via fracking is tremendous. Compounding myriad factors such as melted perma frost decay and ocean bottom effects, suddenly the rate of warming is off the old charts.

It sounds like Jim is seeking answers to save humanity and Iains easily accepts a solution of cutting population by half or more.