Personally? Nationalism & nation states. The longer they stay around, the more likely everyone is to think they're more deserving of X, and pull the literal and metaphorical trigger that leads to hitting the filter.

I recognize that individuality is very much our thing, but that will literally only take you so far.

There's been at least 5 mass extinction events we are aware of where I think over 80% of all species become extinct. I'd probably guess one or more of those could do the trick.

• space

• time

We've been producing noticeable radio waves for a matter of decades. We've been capable of detecting even super-powerful, super-deliberate, super-targeted broadcasts for even less time.

And on top of that, it doesn't look as though our civilisation is going to exist for more than a handful more decades, in any detectable-from-light-years-away form.

The chances of that onionskin-thin slice of lightcone intersecting with that of any other civilisation out there seems ludicrously remote.

I think we're the first. Or rather in the first wave of intelligent life. It could take a thousand years just for a message to reach us. On the theory that life has evolved to this point as fast as possible over the life of our Galaxy, there's no filter. There just hasn't been enough time for contact to occur.

Resources often get squandered on trivial vanity and novelty products instead of being channeled into advancing science and medicine. Imagine if we had a cosmic ledger tracking every resource used to develop simple items, like a pencil. It would show countless fires burned and animals consumed just to fuel the human ingenuity required for lumber, materials, and mining. Now, think about how many more resources are required for rockets, heat shields, and life support systems. Extend that to space stations, energy capture, and escaping Earth’s gravity.The resources on a planet are abundant, and nothing is ever truly destroyed. However, we’ve often allocated too much to building flat-screen TVs, leaving little for constructing even a modest space station in orbit, let alone an interstellar spaceship. It's as if the planet offers a finite amount of resources, challenging its inhabitants to focus on space travel. Only a species wise enough to stay on track can unlock the universe's resources. Otherwise, we risk ending up like Australian pines, choking ourselves out in our isolated star systems, having wasted our potential.

Imagine it like interstellar travelling having a single path to achieve it while the path to self destruction is limitless.

Life finds a way to end itself. There's an ongoing mass extinction event caused by humans. Completely preventable by the way. But we do not prevent it.

I think there are many great filters, but I think one of those filters is fighting over limited resources and wars. Perhaps limited to humans/earth, but I doubt it. Nukes, dropping rocks from orbit, and theoretical (but possible) weapons like black hole bombs are all going to tempt irrational beings to take someone's stuff.

We have to be extremely careful that we don't accidentally trigger a weapon that is going to kill or dramatically cripple our civilization before we become a truly interstellar species. There is so much to learn out there, while so many people are currently focused on the wrong things such as minor conflicts or what children aren't allowed to learn.

It's a society (or the whole humanity) becoming big enough to survive even when ignorant murderers are the elite and the majority of it, and civilized people - a smaller part and almost a property, similar to animals in a zoo.

When such a point is reached, the former will make the transition, and the latter will diminish over time. Then it just has no future.

A bit like with Ottoman empire and Qajar Iran, only on the scale of the whole humanity there won't be someone else to buy weapons and technologies from to keep going. Then some of the previously passable filters will kick in. Like hunger or resource scarcity.

I'm sure simply continuing to live will show me more about possible great filters than most teachers could unfortunately.

For us it's conservatism and its synonyms.

The way the news has been going I wouldn't be surprised if plastic is a candidate. After a little less than a century of rapid development in petrol-plastics we're starting to figure out the long term effects. But the next 1000 generations may be dealing with the fallout.