Originally, the alarmists relied on the "Precautionary Principle". That is an old chestnut favoured by those without a logical argument and/ or cogent evidence.
Now they move on to " the cost of inaction". That is also a logical furphy. Like the Precautionary Principle it could be used as a flawed justification to spend billions on preventing any unlikely catastrophe.
As you say, it is very sophisticated messaging but directed at a very unsophisticated target audience.