It’s the most likely way to prevent a civilizational collapse. Having a dozen countries with nuclear weapons is extremely dangerous, and there will only be more in the future. If there weren’t “countries” at all then we, the whole world, would be a lot safer.
(We might be a lot less free, but we would be safer.)
It really depends on the nature of the world government. If it is focused on fostering top-heavy hierarchical structures (pseudofeudal), it would be more likely to destabilize civilization in the long run. If is is about establishing and maintaining balance (not allowing social structures to become unwieldy), civilization would probably be more robust. And if the world government is inflexible, unable to adapt readily to change, we would be fucked.
Well…yeah, but what kind of fucked? I don’t want this at all at all, but it seems to me that a system of total stasis, kept sustainable, would be the safest of all conceivable systems. You know exactly what you are expected to do. You do that. You live till you’re thirty and then go to the carousel, but, here’s the deal, civilization is absolutely protected. No war, no crime. (No freedom…)
Free is like beer: you can have too much. Right now, in the US, “freedom” is a grossly distorted concept. No freedom is not a recipe for fair progress, but excessive freedom is destabilizing and can end up yielding the opposite of progress,
Well, if I’m getting the context right, we’re looking at maximizing the civilization’s life-span for purposes of the Drake Equation… So, like good Pierson’s Puppeteers, we’ll happily sacrifice freedom for safety.
(In practical terms, we want to maintain just enough freedom to permit for a “problem solving” caste, who can fix things when there’s an earthquake or comet strike, but who are so weak that they won’t go on strike for greater democratic representation. This was one of the problems with the Soviet Union: they wanted scientists…but they didn’t want people who could think for themselves. Problem there…)
I look at it this way.
There are millions of species of living things, both current and extinct, that have evolved on this planet, our only data point.
Only one species that we know of has evolved to the point of even thinking about space exploration. Only one species even has the potential of ever having the ability to make something that will take them into space.
There are living things on earth that have a much longer evolutionary history than man. Some of them communicate with each other and are very intelligent in a lot of ways.
What they don’t have is that compulsion, the innate drive, to build things and use those things to build more things and to create a whole physical and social structure dedicated to the building, consuming and replacing of stuff. They don’t have the concept of “progress”. And I don’t think, even in the absence of man, that lions or dolphins or crows would ever evolve to a place where they could travel to outer space.
So I think we really may be the outlier.
But of course any sentient species is going to find that that’s the case, due to how fast technological progress is compared to evolution.
Even if sentient species are common in the universe, virtually all of them will find themselves on planets with millions of species in which they are the first sentient species.
The numbers I plugged in are certainly arbitrary. You’re correct, the bigger filters are most likely earlier. Abiogenesis may be the biggest, or pro- to eu-karyot…
You, sir, are a bigger Debbie Downer than me! 
Here’s a few other filters that may reduce the odds of making first contact:
Water Worlds: Completely arid worlds are probably most common and probably unable to produce or sustain life. Part land/part water worlds (like Earth) may be extremely rare. Complete water worlds may be relatively common and spark life often. Maybe they even evolve intelligent life often, but these “fishy” aliens may have no inclination or ability to build rockets.
Ice/Water Worlds: These may be even more common than water worlds. And, maybe some evolve super-intelligent species. Maybe they even found a way to make liquid internal combustion and rocketry and such. But, if their habitat is a mile under ice, they’re not going to be sending those rockets skyward. They most likely will not even conceptualize an environment above the ice.
[I have no doubt that somewhere in the universe, at this very minute, there’s an ice/water world octopus-like creature shooting some type of underwater bazooka at his aquatic enemies. And, that’s a battle I’d pay to see]
Genetic Engineering: It’s almost a given that any super-advanced species will master genetic engineering. It’s also a given that once mastered, they will use it to improve their code (why wouldn’t they?). This may be step 1 of super-species enlightenment: weed out bad traits. What’s a common bad trait? Aggressive competition, for one. Sure, survival of the fittest is important to evolve from microbe to top banana/apex species. But, once you become top banana, aggression is a bug, not a feature.
Wild expansionism and empire-building are part and parcel of survival of the fittest. That will be weeded out for sure. Genghis Khan = old school; Star Trek Prime Directive = new school.
Step 2 of super-species enlightenment is to go cyborg. “All-organic” is gooey and error-prone. “All-inorganic” is prone to failure. Question: would you rather have a femur made of bone, or a femur made of titanium? Answer: bone. Titanium is stronger than bone, but, although bone sustains frequent micro-fractures, it micro-repairs itself continuously, making it ultimately stronger.
So, half man, half machine is what we all should aspire to. Download your consciousness into a cyborg template and never look back. Then, take the next step: go tiny and make your world extra-dimensional. You and your entire civilization don’t need a lot of space, you just need a lot of dimensions. Turn on, tune in, drop out. Spread in, not out. No need to leave your planet, or star system, or galaxy.
It’s unlikely we will ever make contact with extra-dimensional races of tiny cyborgs, even though they are swarming all around us, like gnats.
I’ve stopped swatting gnats for fear I may be destroying civilizations of billions. 
Any ET who comes across Trump or his MAGA followers today might come to the same conclusion. Oooh, snap!
The most common bad trait is a thing known colloquially as “spaghetti code”. The genome is absolutely loaded with it, if not entirely composed of it. If you change this one gene here, it affects a dozen other things. The first thing an advanced race would do is reconstruct the entire genome to be modular, so that mods can be made easily and cleanly. And maybe include a telomere repair structure, so that aging is less of a thing.
The issue with water worlds is, given a sufficient depth, water undergoes a phase change at a sufficiently strong pressure, locking any rocks & minerals away from any remotely practical access, be it natural or technological.
Here is the classic image of the Earth’s water. The Earth is not “part land/part water”, it is a really big rock with a micro-thin layer of water on it.
Don’t underestimate the difficulty of detecting alien civilizations. If there were a dozen civilizations within 100 light years of us that used exactly the same technology we use, we’d have no way to know. Omnidirectional radio signals such as broadcast radio would need a large dish to detect even 1 light-year from here. Alpha Centauri could have a technological civilization on one of its planets and we wouldn’t know about it.
In addition, even if they were beaming signals to us directionally, we’d have to listen at the right time, on the right frequency, and recognize what we hear as artificial. Efficient spread-spectrum communications sound like noise and can be hard to detect as coherent.
Then there’s the problem of technologically-induced radio silence. Earth is becoming ‘radio dark’ as we transition to optical communications, spread spectrum low power communications, fiber optic connections, etc. If other civilizations do the same, there may be only a few-decades-long ‘window’ during which they emit powerful radio signals.
For that reason, hearing galactic communications on radio frequencies are incredibly unlikely, no matter how populated the galaxy is. Radio SETI up to this point was always a longshot.
I believe we have a much better chance answering the question of extra-terrestrial life through optical SETI - looking for markers of life on other planets, or looking for signs of massive technological construction like Dyson Spheres, or perhaps finding evidence of near-light-speed ships through radiation or gravitational lensing or something like that.
The next twenty years are going to be very illuminating. The new generation of 30 meter telescopes, plus the James Webb telescope, should allow us to detect bio-markers in the atmospheres of nearby exoplanets. All-sky survey scopes like the Vera Rubin Observatory (formally LSST) will catch transient information like potential flashes from extraterrrestrial laser communications that intercept Earth’s position or other short-term technological signals.
If by 2040 we still haven’t found any signs of life anywhere in the universe, the Fermi paradox will THEN become more acute. If we find lots of exoplanets with evidence of life but no tech, that will help us narrow down the terms in the Drake equation. By then, we should have extensively examined the atmospheres of hundreds of exoplanets, and discovered many more in the ‘habitable zone’ of sun-like stars, which we can’t easily do today. If we look at hundreds of planets in ‘habitable’ zones and find no life markers on any of them, that will be interesting.
Up until now, we can simply say that we’ve barely started looking, and it shouldn’t be much of a surprise that we haven’t found anything yet.
Indeed, Earth is not half land /half water, but the water part is deep enough to sustain life and perhaps allow for an aquatic technological civilization if they had the means to manipulate elements from the sea floors…and providing humans got out of their way. As John DiFool alludes to, much deeper water worlds could not evolve a technological species, because they would not have any material to work with.
Excellent post @Sam_Stone, but I do want to pick up on the last line a little:
The fact that we even have to look is already a surprising observation in many ways. A more advanced species could have left ample evidence throughout the galaxy including visiting earth; there’s been enough time for all this.
It’s a mystery novel even before we get to the chapter on SETI.
Sure, I’ll give you that. But what makes you think they haven’t? There could be a probe going through our solar system very year, monitoring life on Earth, and until perhaps the last three decades we would have been completely oblivious to it.
Even if aliens landed an outpost on Earth in the Mesozoic, say, all traces of it will be gone.
On the other hand, once we really start exploring the Moon, who knows? Anything left on the Moon more than a few million years ago would be buried under a whole lot of regolith by now and very difficult to spot from orbit.
On the other hand, if you wanted to observe Earth for a long time from a very protected place, under a lava tube skylight with a few of Earth from the bottom during the right alignment. A probe would be protected from cosmic rays, most micrometeorites, regolith rain, solar wind, etc.
Maybe when we finally look down into the Marius Hills skylight, the first thing we’ll see is our reflection in a giant mirror. (-:
It seems most likely that people from other systems, what ever form they might take, would be most interested in not making contact with us (or other advancing beings elsewhere). After all, we, in particular, are a rather scruffy, unpredictable, dangerous lot. Interesting, perhaps, to study but, so far, mostly harmless.
When we at last manage to reach the level that we can locate them and make contact, we will have climbed out of the crucible of development that has shaped us into a society worthy of contact. There are things that we will have to learn before we can become suitable citizens of galactic society.
They really prefer that we not just know about them. It is on us to figure out the path to their porch.
The burden of proof works the other way round.
Right now, we have no evidence of being visited, and that’s a significant observation.
Sure we can think of plausible seeming reasons why that might be, and my personal feeling would be the same as yours and eschereal’s; that a hyper advanced species would have the means and probably motive to spy on us in a way we could not detect.
But we don’t know that, it’s just speculation. And that’s essentially the point of the paradox: based only on what we know, we don’t know why we have not seen lots of evidence of ETs here or elsewhere.
A few caveats regarding the self destruction process. It doesn’t actually have to be self destruction it could be destruction from other causes, (rogue comet, gamma ray burst, super volcano etc.). Also it doesn’t have to destroy the intelligent life, just knocking it down to the stone age so that it has to start from scratch in its efforts to colonize stars would be sufficient. Also note that we were relatively lucky in that we had vast reserves of stored energy in the form of fossil fuels to jump start our technological revolution. Making the transition from water wheels and wood stoves to solar cells and nuclear plants is going to be particularly difficult if the previous civilization used up all the readily available coal and oil 10,000 years ago or never had it to begin with.
No, not lions or dolphins or crows. Raccoons. They practically have hands already.
