Does it really?
Stop all human activity that puts CO2 into the atmosphere, huh? A good start?
So nobody burns anything. Put humans back to pre-human times, before the taming of fire. How many heat sources can you name that don’t ultimately come from burning something? And how quickly can they be made available to billions of people? Hmm. Gonna get kinda cold in the non-equatorial latitudes, where the majority of humans live. But really, most of them probably won’t freeze to death. They’ll starve first.
All industry stops. No more steel, or any other metals. No plastics or any other sort of chemically produced materials. Not even ceramics or fired clay. And of course all transportation stops, unless you want to walk it. (Even then, you’re exhaling CO2. Oh oh! Problem!) No cars, trucks, trains, planes, powered ships - none. No way to move freight anywhere. Not even horse-drawn carriages or ox-carts. Horses and oxen both emit CO2 (along with methane and other noxious things, so terrible for the atmosphere). So, no food gets moved from place to place. Every city in the world starves to death. Quickly. In fact, not much food gets produced. Everybody who doesn’t have a farm, and the skills to work it without tractors, trucks, fertilizers, or irrigation is going to get a mite hungry.
But hey, isn’t all that a small price to pay?
Basically, your plan is: Destroy civilization and kill off all or most of the human species. That’s the inherent result of the plan to “stop doing things” that can only possibly (emphasize possibly) be contributing to a possible effect (ACC) that might possibly result in a possibly undesirable result (a warmer planet).
Seems just a tad drastic to me. But then, I happen to have a perverse and apparently unpopular affection for the human species.
The problem with people who have the attitude of “Gee, even if the whole ACC theory has only a one-in-a-million chance of really being right, isn’t it better not to take any chances?” is that they never follow through on what their “better safe than sorry” notions really entail.
Fortunately, the human race isn’t going to revert to pre-fire anthropoid days, no matter how many hysterical Newsweek articles are printed (and distributed with CO2-producing materials and machines, later to be thrown away and burned - thanks, Newsweek, for doing your part in the fight against deadly global warming) proclaiming that “our best scientists” (try to define that term in any meaningful way) all say The End Is Nigh and we must Repent of our sinful technological ways.
But the whole foofaraw is pretty entertaining, anyway. Actually, that’s one of my favorite things about the human species: their entertainment value. It’s just a pity H.L. Mencken isn’t around for this; he’d have loved it.