Where do these sources establish that logistically effective mitigation is also cost effective? That is the real question we should answer. Does the benefit exceed the cost?

There are several possibilities: (1) Climate change is true and humans can stop it. (2) Climate change is false. (3) Climate change is real but humans can not stop or reduce it enough at this point in a cost justified way, i.e. the costs of mitigation exceed the damage done by climate change.