This depends heavily on assumptions. Consider this : the oldest cryonics patients have survived more than 30 years. The loss per decade for reasonably well funded cryonics organizations is currently 0.
If you check a chart of causes of death, the overwhelming majority of causes are ones where a cryonics team could be there.
You would have to choose a legal method of suicide in some of these cases, however (like voluntarily dehydrating yourself to the point of death), or your brain would deteriorate from progressive disease to the point of probably being non-viable for a future revival.
As for long term risks : ultimately these depend on your perception of risks to human civilization and the chance of ultimately developing a form of nanotechnology that could scan your frozen brain and create an emulation at minimal cost. I personally don't think there are many probable causes that could cause civilization to fail, and I think the developement of the nanotechnology to be almost certain. There is no future world I can imagine where eventually a commercial or governmental enitity would not have extreme levels of motivation to develop the technology, due to the incredible advantages it would grant.
This is my personal bias, perhaps, but let's look at this a bit more rationally.
a. How could a civilization ending event actually happen? Are nuclear escalations the most likely outcome or are the exchanges ending at a city or 2 nuked more probable? b. What could stop a civilization from developing molecular tools with self replication? Living cells are an existence proof that the tools are possible, and developing the tools would give the entity that possessed them incredible power and wealth. c. Cryonics organizations have already survived 30 years. Maybe they need to survive 90 or 120 more. They have more money and resources today, decreasing the probability of failure with each year. What is the chance that they will not be able to survive the rest of the needed time? In another 20 years, they might have hardened facilities in the desert with backup power and liquid nitrogen production.
And so on. This is a complicated question, but I have an educated hunch that the risks of failure for cryonics are lower than many of the estimates might show. I suspect that many of the estimates are made by people who suffer from biases towards excessive skepticism, and/or are motivated to find a way to not spend hundreds of thousands of dollars, preferring shorter term gains.
The civilization-ending risks are the most worrying from my point of view. Basically, I see a couple of scenarios:
Technology never gets anywhere near the point where we can revive frozen brains. Industrial civilization collapses first through a combination of resource constraints, environmental damage, and devastating wars; most likely, these all happen together and feed off each other. This doesn't immediately cause human extinction, but the probability of a future industrial civilization arising from the ruins is very low, because all the easily-extrac
I heard that women are difficult to convince when it comes to signing up for cryo. In mentioning cryonics to a dying person, there seems to be a consensus that it's not going to happen. I encountered a post: Years saved: Cryonics vs VillageReach, which addressed my main objection (that the amount of money spent on cryo may be better spent on saving starving children, especially considering that you could save multiple children for that amount of money with high probability whereas you save only one life with low probability by paying for cryo). Now I'm open to being persuaded.
My first instinct was to go read a lot about cryo, but it dawned on me that there are a lot of people here who will want to convince family members, some of them female, to sign up - and these people may appreciate the opportunity to practice on somebody. It has been argued that "Brilliant and creative minds have explored the argument territory quite thoroughly." but if we already know all of the objections and have working rebuttals for each, why is it still thought of as extra difficult to get through to women? If there were a solution to this, it would not be seen as difficult. There must be something that pro-cryo people need for persuading women that they either haven't figured out or aren't good enough at yet.
So, I decided to offer myself for experiments in attempting to convince a woman to sign up for cryo and took a poll in an open thread to see whether there was interest. I don't claim to be perfectly representative of the female population, but I assume that I will have at least some objections in common with them and that persuading me would still be good practice for anyone planning to convince family members in the future. Having a study on persuading women would be more scientific but how do you come up with hypotheses to test for such a study if you have no actual experience persuading women?
So, here is your opportunity to try whatever methods of persuasion you feel like with no guilt, explore my full list of objections without worrying about it being socially awkward, (I will even share cached religious thoughts, as annoyed as I am that I still have them.), and I will document as many of my impressions and objections as I can before I forget them.
I am putting each objection / impression into a new comment for organization. Also, I have decided to avoid reading anything further on cryo, until/unless it is suggested by one of my persuaders.
Well, have fun getting inside my head.