[Kathula]

First of all, there's no need for 7 billion people to exist to fulfill being a civilization. Surely our civilization could exist of just 1 million people if it comes to that.

Secondly, the climate change "catastrophe" isn't what we need to be worried about. Rather one of those events that has occurred before on earth, wiping out almost all existing life. But considering some non-intelligent life forms, or at least life forms without our superior intelligence, survived those events I'd bet that we would survive them too. Considering we can detect them, and (somewhat) protect against them.

Nuclear War is unlikely to happen since any instigator know it would come at tremendous cost. Also, the more countries that have nukes the better, since it levels the playground. Even if nuklear war happens, it wont wipe out all people, all communities.

[cthalupa]

If in a group of a million people you had enough people interested in and capable of doing the science necessary for making progress interstellar communication or travel, we would have many many many times more people working in those fields today.

A civilization with only a million people in it would have priorities vastly different than our own.

[tsimionescu]

The human species doesn't need to be wiped out for civilization to end,at least at the level of being interested in interstellar communication. It's true tho that civilization may spring up again after some time, so perhaps that should be factored into the equation.

And nuclear war had been only narrowly avoided on around 13 documented occasions in the last 70 years [0]. Some of these events were avoided by happenstance, not any kind of systematic protection. This kind of luck will not continue forever. And if it does break out, right now we don't really understand what may happen to the planet if the US or Russia unleash their full nuclear arsenal, rather than just bombing one or two cities.

[0] https://en.m.wikipedia.org/wiki/List_of_nuclear_close_calls

[demosito666]

> right now we don't really understand what may happen to the planet if the US or Russia unleash their full nuclear arsenal

Nothing will happen. Planetary nuclear arsenal yield is dwarfed by a single large vulcanic eruption, and those happen regularly. In fact, modern nuclear arsenal is barely enough to destroy military targets and major cities of both parties. Direct casualties will be in millions, but probably in single digits of them.

In other words, it will be a major humanitarian catastrophe, but nothing humanity (or even a major world power like US) can't survive. Probably the biggest change would be due to large areas rendered uninhabitable for decades, but then again, plenty will be left and "uninhabitability" is a matter of life quality standards. People live in Hiroshima and Chernobyl just fine.

[tsimionescu]

You're free to believe what you want, but the peer reviewed studies that have been conducted with current climactic models predict significant global cooling that would lead to at least global famine. The crux is not the power of the explosion, but the amount of soot generated by detonating high - yield weapons in huge cities.

And people do not live in Chernobyl at all. However, it's not really relevant to a discussion of nuclear weapons, as nuclear plant meltdowns are a completely different problem. For sure if the Chernobyl core had melted down and exploded nothing would be living in Ukraine at all, and possibly a much larger area. Hopefully though, that is one area though where technological progress has actually significantly reduced the chance that it would ever happen, in a systematic manner.

[demosito666]

Not matter the opinion, "nuclear winter" concept is a belief, you are totally right here. It has never been a scientific question in the first place, the idea was largely accepted for political reasons. Wikipedia [1] has a short overview of the discussion on the topic, but in reality there is no debate on that for a long time: one can't really argue in favor of milder consequences because he'd be labeled as a militarist and all. And I agree that this is one of the few discussions that we probably shouldn't have.

But in general: all the articles greatly exaggerate the volume of nuclear arsenal (tenfold), the number of actual nuclear detonations, the territory of fire and ash yield of the fires. And even then, the planet has tolerated all those at larger scale in volcanic eruptions and forest fires.

Napkin math: US/Russia arsenal is about 1500 warheads on 500-1000 carriers each, which is about 500MT combined. Out of those optimistically maybe a half will detonate on each side (they will be destroyed in preventive strikes/intercepted/etc.), which leaves you with about 125MT total yield - about the yield of a couple of Tsar Bombs that was detonated in 1961 without any consequences whatsoever. The majority of the strikes will be on military targets in the middle of nowhere, where there won't be any fire at all. The rest will fall on modern concrete cities that don't have much fuel either.

> And people do not live in Chernobyl at all

They do, there are about 3000 people working there at any given time and even more living there illegally. Also, animals have no problems living there whatsoever and in fact the ecosystem is in a better shape due to low human activity. Also, you are aware, that Chernobyl power plant itself was operational until year 2000, right?

> nuclear plant meltdowns are a completely different problem

I absolutely is, and in terms of ecological consequence Chernobyl is far more severe than thermonuclear warhead detonation. The core HAS melted down and exploded, pieces of graphite rods were found as far as hundreds of meters away from the building.

I'm not saying nuclear war is nothing to think about - this would be a major catastrophe. But it's very unlikely to end the civilization.

[1] https://en.wikipedia.org/wiki/Nuclear_winter#Criticism_and_d...

[tsimionescu]

The Chernobyl facts you bring up are very interesting. I had no idea that the plant kept operating for so long. I knew that there were people who stayed behind, and that there are workers around the exclusion area, though I admit that I would have imagined significantly lower numbers.

[demosito666]

Sorry for the spelling, time to go to sleep.

[ganafagol]

> Also, the more countries that have nukes the better, since it levels the playground.

That's the American "best thing against a bad guy with a gun is a good guy with a gun" attitude. Empirically this does not hold true. With the density of lethal weapons in the U.S. and the statistically lower safety from gun violence compared to other developed countries, it's safe to assume that the world would be a safer place with a reduced number of countries having nukes (or ideally none of them) rather than an increased number.

[fennecfoxen]

I'm not sure that it's safe to assume that the dynamics of international relations among nuclear and nonnuclear states can be so tidily extrapolated from the dynamics of society and interpersonal relations among gun-owning and non-gun-owning humans acting in their individual capacities.

[ganafagol]

Maybe not. But it's at least an attempt to a somewhat informed hypothesis, which a simple statement like "since it levels the playground" definitely is not.

[fennecfoxen]

true