This scientist explains it here, jump to the 32:30 minute timestamp: https://youtu.be/7TbDAFQkqj4

Ideally, any large non populated area would work for that measure, but the outback would be the best spot according to many scientists, because the ozone is least dense in Australia compared to anywhere else on the planet, assuming we do nothing about the current climate by 2050-2070, it would also need to be done repeatedly every 4-7 years as well to get the global average back down to where we are now. Of course, I’m going to get downvoted in this subreddit, because you guys don’t understand the concept of kicking up smoke/dust around an ozone to block out extra sunlight (nuclear winter) to make up for the weakest spot in our planets ozone layer, it is also why Central Australia/Outback is uninhabited right now, as an Aussie you should know this, and since the ozone is weak in that region, it’ll be even more uninhabitable in 3-4 decades, like with 90% of Canada’s population living within 100 miles of the US border, the overwhelming majority of Australia’s population lives near the habitable region near the sea in the south east or to a lesser extent the edges of the island in other spots around the island. Assuming nothing is done by then to stop our current level of climate pollution, (the US/Chinese government need to listen and drop Coal Power), that’s what will wind up happening, because Australia would become uninhabitable not long after the middle east if the global average rises up anymore after that anyway. And again, we’d face another mass migration crisis because a specific region on earth is going to get too hot to house human beings.

It wouldn’t be nuking all of Australia either btw, people on the edges of the island would be unaffected by any fallout, South East Australia (where most people live) would be 2,400km from the impact site(Assuming Australia is still habitable by the time things get that bad that we need to resort to this stopgap measure, because it’d be next right after the middle east in terms of things getting too hot for humans to continue to live there).

All of this does ignore AGI/ASI getting here, personally, I don’t think things will get that bad before ASI course corrects, but if we don’t get ASI, I currently lack faith in humanity dropping things like coal power plants anytime soon, because both China and the US want to remain the world’s dominant superpower and coal is the cheaper but more pollution heavy method, it boils down to that and rich tycoon’s greed. And yes, you’re right, the idea is for us to course correct now, as I said, humanity is going to make it, but a lot of people will indeed die if we don’t change our current course soon, there still is time by the way so that these migration crisis don’t happen (at this point it does look like things are going to get spicy in the middle east), that’s where alarmists/doomers are wrong, governments just need to start by outlawing coal power and outlawing it globally, that would be a great way to stop things getting too bad, but in the end I do lack faith in the ability of humans to put aside their greed, so we better hope we get AGI/ASI soon, which in that regard I am optimistic because progress in AI has been outstanding and far ahead of schedule.

Addendum: It’s not just countries like China or the US either, the same standard needs to be applied to the developing world as well, we should launch a global initiative to ban coal and make sure developing nations have access to nuclear or reusable power sources, because a lot of African countries are also going to be industrialized soon, and sadly many of them are already turning to coal just like we did for cheaper energy production, every country is going to have to pitch in on this. Because if one country keeps knocking up massive amounts of pollution it’s going to harm/kill people in the hotter countries.