The U.N.'s climate body on Monday published its latest draft text of the deal it hopes to reach at the COP28 summit in Dubai, which includes a range of actions countries could take to reduce emissions.
More seriously, it would at best delay things for 10 years, and that’s if our current understanding of the climate turns out to be wrong and a nuclear winter could indeed actually happen in the first place.
The theory behind a nuclear winter was that in the 80s some scientists thought the secondary fires caused by detonating a bunch of nukes simultaneously in forested areas would combine to be powerful enough to carry the ash into the upper atmosphere. In the 2010s hover Australia had a wildfire big enough that according to the nuclear winter theory it should have easily demonstrated said effect, but dispite careful observation it didn’t, which is also what more modern climate science predicted.
Fun bonus fact: In a full scale nuclear war the majority of the projected casualties come from a breakdown in gobal trade leading to a lack of western produced fertilizer and subsequently food being grown in Africa. The same food production that is going to be heavily hampered by climate change. Thankfully there’s more time to mitigate it with climate change, but it’s still liable to be one of the biggest issues in a 2+C world.
Possibly, but if your talking about an actual nuclear exchange rather than a rather dramatic reenactment of the French Revolutio it would probably just make things much much worse for the climate. Your at most looking at twenty five percent reduction in humans, and the remaining seventy five percent will probably be too busy repairing and rebuilding infrastructure to prioritize further emissions reductions.
Indeed since you now have a demonstrable reason to dedensify urban areas in favor of small towns, becuse things like batteries and solar panels have complex global supply chains while for much of the world oil, gas, and coal are available close by with easier to build infrastructure, and because you now need to make a vast quanty of new stuff to replace what was lost, well net result would almost certainly be a small drop followed by a continued increase in emissions for the next few decades before things got back to normal and decarbonization efforts could resume, now aiming to limit things to 4 to 6C.