It seems to me that responsible way to think about this sort of calculation would be to include something like QALYs lost due to premature death caused by fossil fuels on one side of the ledger, and QALYs gained due to cheap energy (supporting the development of advanced medical technology and food abundance) on the other.

It has always been a problem that the mental trick of weighing costs and benefits doesn't come naturally to human beings, but I've definitely been noticing it more and more during this era of COVID, wherein the idea of tradeoffs and cost/benefit, which should be central to any pandemic response, is rarely invoked.