We are often hustled along on climate with claims that the crisis is too urgent for deliberation or evidence-gathering, that we must go faster and do it now right now. But Tony Brown asks a very important question about such cries for reckless action on Watts Up With That?, namely: If we reach net zero carbon in 2030 as Extinction Rebellion wants, or 2050 as the Paris crowd prefers, what next? How long does it take for CO2 to start falling to “safe” levels and then when do temperatures fall back to “safe” pre-industrial levels. Another question the alarmists prefer to talk around is precisely how large the costs of reaching net zero would be. But first things first: If we do win this race, what if anything is the prize that justifies whatever the costs are?

There is another related question that is also rarely asked. But we have asked it and do not intend to stop: What makes anyone think, if we could in fact stop temperatures from increasing, and gently lower them again with our superior wisdom and technology, that the temperature in 1950, or 1850, or 1750, is the “right” one at which we should be aiming? Or indeed 49 BC, or 5000 BC, or 49 million BC?

Various zealots including Al Gore and John Kerry have claimed that temperatures were stable for thousands or, in Kerry’s spectacularly ignorant case millions, of years and thus it’s right because it’s what nature intended. But since they’re wrong about an easy target of “relative climate stability“, and nature has been all over the thermometer over the years, including a much warmer Earth that was spectacularly hospitable to life, we need to come back to this issue at some point.

It’s one thing to say it’s terrible if temperatures rise because they’ll keep rising. But if it’s plausible that the curve will taper off (for instance because Equilibrium Climate Sensitivity represents the expected increase per doubling of atmospheric CO2 and each doubling requires twice as much, duh) then the argument has to be not that a slightly warmer planet is bad because it’s a sign of the fire next time, but because it’s already disastrous. As CNN just claimed, joining the chorus of vultures over California wildfires: “This is what a world looks like with just over 1 degree of global warming” over images of California wildfires with the subhed “Entire towns have been burned to the ground”.

CNN is evidently unaware that it was warmer in the Middle Ages and the Roman Warm Period without the globe becoming an incinerator of species in either period. But for good measure it threw in that “The planet could get much hotter” before quoting that calm and dispassionate moderate Michael Mann that “It’s a matter of how bad we’re willing to let it get” (that fixation with will again) and “If we keep planetary warming below 1.5 Celsius, which is still possible given concerted climate action, we can keep climate change impacts within our adaptive capacity. If we don’t, we will likely exceed it.” Which is vague and terrible and presumably means the hurricanes will spread the wildfire into the flooded cities and we’ll all have zika or coronavirus and so forth.

Still, one disaster at a time. And one question at a time. So we ask with Brown: Assuming you’re right that man-made CO2 is causing warming and that warming is bad and getting worse, how much benefit will we see from reaching your targets and on what time scale? Because if the answer is none, or none for centuries, then we should obviously either find a better plan or just stop trying. It’s bad enough sacrificing our way of life to save the planet. But it would be fatuous to sacrifice it without saving it.