A castle built on sand. The only way to take the premise of this claim seriously is to ignore data for the past 100 years.
When I was in the US military, we all complained about the Body Mass Index standards. They were based on the WWII era "normal". Men were smaller. Less muscle mass. Shorter. If the average fit American young man tried to fit into a pilot's cockpit from the 1950's, it would feel quite cramped. Like it was built for much small people. It was.
We have certainly climbed the Kardashev scale since the 1950's. To what degree is a matter of contention. But, all would agree that we have moved up the scale.
Muscle atrophy has not been correlated with the growth. The opposite seems true. The average American, both male and female, has more muscle mass than in 1924. A 2024 person spends significantly more time on average in a gym pushing their muscles to hypertrophy than in 1924.
In addition, it is likely that the romantic picture of the average laborer "bodybuilding" is fictive and ignores how muscle atrophy and hypertrophy works. Most laborers are NOT doing activity that leads to hypertrophy. They are staying well within cardiovascular zones of muscle activation. Hence, bodybuilders as we know them are largely a modern phenomenon. And they are certainly WAY more muscular.
Seems the model that underlies this claim is built on seemingly demonstrably false premises.
It's worth noting that the anatomic accuracy of classical statues like Laocoon, the Farnese Hercules, etc. indicates that there were at least some men walking around in antiquity with an amount of muscle mass that could only be developed by deliberate hypertrophy training of the whole body, as opposed to just getting muscle as a side effect of specific athletic training. It seems like these people were doing something quite similar to modern bodybuilding, goal-wise.
> The average American, both male and female, has more muscle mass than in 1924.
This is true, but sort of a sleight of hand -- obese people that don't exercise have more muscle mass than non-obese people who don't exercise, just to carry around all of the fat. And obviously the average American, both male and female, is more overweight/obese than in 1924.
(I agree with basically everything else you say, though.)
Agreed.
Anecdotal: I helped my dad a few years ago do a lot of genealogy. He had pictures going back to the late 1800s for one branch of the family that just arrived from Ireland. Most of the men were shirtless and you could count every rib. There was very little muscle.
> The average American, both male and female, has more muscle mass than in 1924.
I don't necessarily disagree with your thesis, but I'd be genuinely interested in reading the source on this, unless you just mean because people are bigger overall they have more muscle as a function of weight.
The major federal government food assistance programs came out of findings in WW2 that many potential recruits were literally malnourished and underweight. They had grown up poor and starving during the Great Depression. Beyond the human tragedy this was a national security issue. Some men were too small and weak to meet military standards.
Bold take to proclaim we'll figure out interstellar travel before we figure out how to prevent muscle atrophy.
I think realistically we have to reduce our body mass by 99% if we want to go interplanetary, much less interstellar. It's extremely expensive to drag around 70kg of meat and minimizing weight is key to making solar sails work.
We definitely don't need to reduce it for interplanetary travel.
We know how already: exogenous testosterone (or other, more anabolic hormones), but that has downsides like left-ventricular hypertrophy, masculinization in women, and (usually reversible) infertility.
Yes, yes, it's safe to presume GP means "figure out muscle atrophy without the well-known terrible side effects of current treatments" from even a mildly charitable reading of his comment.
Interstellar travel is not a prerequisite for K1 or K2.
Will we even remember what a muscle is at that point?
also bold take to proclaim we'll still have human bodies before moving up kardashev scale
We are human bodies.
Homo sapiens is subject to speciation just like every other animal.
Then there's cyborgs...
Replace it one cell at a time. Ship of Theseus awaits to set sail.
Bodies are processes, like chemical reactions or baseball games, not "objects." No problem.
objects undergo processes. atoms in your body are replaced over a period of hours-years.
Is a tornado an object or a process?
Is a thought an object or a process?
Amen.
also bold take to proclaim, that humans will be required for teleoperation...
We already know how to prevent it, it’s called anabolic steroids or testosterone. Once I read a study that showed sedentary people on testosterone gained more muscle mass than people actually working out.
Bhasin et. al 2001. If you get in many internet fights about bodybuilding, it's an important part of your repertoire :-)
If you don't get in many internet fights about bodybuilding, testosterone can fix that too.
This is me. I cycle on and off testosterone (100mg/w for 12 weeks typically) and combine it with light exercise (20-30min of lifting 3x a week). Other than that my only exercise is walks with my dog (typically ~45min). The rest of the time (~12hrs/day+) I'm at my desk. When I'm on testosterone it I definitely see major results, just from that level of exercise.
My perspective on it is it is borrowing from the future. I feel better while on it, but it's just changing what the problem is. I've turned a sedentary lifestyle issue into a hormone issue. There are side effects (ie enlarged heart in the future). I'm using it as a crutch while I have a demanding job that keeps me working for longer hours.
FWIW the research does not show enlarged heart or many of the other negative side effects for people taking TRT at therapeutic, physiological doses (like, your 100mg/week is not supraphysiological for many men with low T). (And if you aren't low T, why take exogenous T? Especially given your concerns about borrowing from the future.) The heart issues and other bad side effects happens when bodybuilders take 200-5000 mg/wk doses.
Those are really unpleasant and dangerous to take and basically not an option for half the population though
My first thought is the study must be capturing what they call “newbie gains” or “diminishing returns”. The sedentary experimental group can gain muscle so fast because they are just starting out on their journey.
Also, it kind of reminds me of the idea that athletes take these as performance enhancing drugs because it helps them in the same way that following a strength-training program would help them.
It isn't just beginner gains. Testosterone and anabolics are really, really effective. (They also have horrible side effects.)
Testosterone is a very broad spectrum way to mess with your whole body.
Much better to do something targeted like reduce myostatin.
You probably know this, but -- while the myostatin area is an interesting subject for research and drug development -- unlike testosterone, therapies are not commercially available (yet).
They'll also tear their ligaments and tendons when they go to use that muscle mass...
Yes that’s how you get an enlarged heart and die by 35.
I take it you're talking about people like Dallas McCarver, whose autopsy found his testosterone levels to be extremely elevated [0] because of the number and volume of substances he was taking. If you're just taking base TRT and actually do cardio alongside weightlifting, you'll probably be fine.
[0] https://drmirkin.com/histories-and-mysteries/dallas-mccarver...
Great-grandparent comment is talking about supraphysiological doses of test and anabolics, not replacement-level T (TRT). I agree that physiological dose TRT in people with otherwise-low T is safe.
Fundamentally the heart is a muscle and anabolic steroids and test stimulate muscle growth in muscles at a cellular level. There’s no way to have one and not the other.
That’s just the tip though. They have all kinds of far reaching effects ranging from curtailing height, significantly reducing IQ, constant skin breakouts, altered moods, hair loss, severe anxiety, paranoia, kidney and liver failure, bone breakages etc, severe and permanent decrease in the testosterone you naturally produce etc.
Even more importantly, test causes hair loss.
Sort of. Some fraction of test (natural or exogenous) converts to DHT via 5α-reductase, and some people (not everyone) have DHT-sensitive hair loss.
It truly is a wonder therapy with no known side effects. I pair it with Ozempic! /s.
Not that our muscles aren't important, but I'm less worried about our muscles atrophying as a result of technology and more worried about our brains atrophying as a result of technology.
More people read more things off of more screens than ever before in history.
This fear is unfounded. It isn't the proliferation of technology that is making people dumber; it's the American cultural deemphasis of education, entirely independent of technology.
> why would anyone do such an expensive thing?
I find it amusing that somehow resources would still be constrained as we go closer to be a Kardashev I civilization.
The timescales involved in us becoming even a K1 species are probably enough to say we won't be anything resembling current humans, neither physically nor socially.
I don't think I actually agree with this guy. As anyone who is trying to grow their body knows, rest is important -- just as important as working out and workouts aren't all-day affairs either. You can get very strong with only a few hours/week in the gym.
That's different than subsistence farming, where you're doing a lot of work at sub max levels most every day. You may get strongish, but you won't get large.
Consider a modern day elite marathon runner, who works out >10 hours/week. They can only do so at sub max levels of effort. The top end are prone to injury (overtraining), and the training itself limits muscle development.
The majority of us are getting weaker and fatter. A few of us are still testing the limits of human physiology. The difference is you have a choice to be whatever part of the spectrum you want to be. Most choose "weak and fat".
Much of this is tied to nutrition, which I don't think is talked about in the fine article. Same story, we have a choice to eat the best for us food, or to eat crap. That wasn't always the case for the subsistence farmer.
You can get large with decently defined muscles with medium time investment.
But real strength, like farmers traditionally had, is hardly visible and needs an insane amount of time just handling heavy weights.
These people look completely average but can easily handle way more weight than the totally jacked body builder can.
But if the goal is mainly the physic and not strength... Then yes: a few hours a week is plenty
I wouldn't claim they can handle more weight (since top bodybuilders are lifting insane weights to get those muscles), but they can certainly do it for much longer than bodybuilder who trains for short bursts of maximum efforts. Our body literally builds only around the effort it experiences, and 0 more, running in absolute minimalist mode.
If you ever ie been running, say at 10km consistently, try to move that one day to 20km while maintaining the intensity. Significantly harder, you may experience various connective tissue issues too and not just muscle and energy management.
Or break a leg or two like I managed with recent paragliding accident, don't move one of them for 3 months and you will find that body, in its quest for lowest energy spending at all costs literally consumed all connective tissue to barest minimum, so stuff just doesn't move at all. I guess other mode didn't develop since in our distant past, like in rest of animal kingdom, broken leg meant certain death.
Silly.
1. Myostatin inhibitors are already in development. We're already using a drug that stops us from getting fat, why would we not use a drug that prevents atrophy?
2. This is entirely focused on what would be efficient at a global scale, while decisions are made on individual's desires. People (in general) want to look muscular and fit; it's as hardcoded into our reproductive desires as anything else is. Given increasing resources, is it reasonable to assert that people will choose to totally forgo their biological body? Why is it impossible for them to have the same productive advantages while retaining a physical body for when they want it?
Human desire trumps production, even in the long term, or at least medium term. I could eat monkey chow every day and never have to do dishes or cook ever again, and save an extra 10 hours a day. I could wear the same thing every day so a machine can fold it. I can put my brain in a jar to avoid commuting. But no matter how much technology advances, if I still spend 8 hours working with my brain implant or whatever then I'm still doing at worst 24% as good as the guy working 24/7. Why would it ever be worth giving up such basic human pleasures as eating or sex just for 4x the salary?
> Given increasing resources, is it reasonable to assert that people will choose to totally forgo their biological body?
Maybe sexual selection will be altered by further technological changes. If we manage to technologically replicate the feeling of amazing sex with super hot individuals on demand, there would be little point in expending the effort it takes to have a great body for that purpose.
There are plenty of other reasons great to exercise regularly. For one, it helps stave off the negative effects of aging in a way that I doubt a pill will ever manage. But that's also an argument for ridding us of these pesky bodies that we have to be carried around in.
If paying the rent is our aim, who knows what unnecessary limbs may be disposed of. What need has a programmer for legs? Or arms even, if neuralink happens.
This post vastly under-estimates the amount of malnutrition in most societies pre-modern times. Even with heavy physical labor, I would be willing to bet that the average physical laborer in say 1800, who we know was significantly smaller, would be weaker as well. Farmers and people who do physical labor do build muscles, but they also have modern high nutrition diets and medicine.
Related. Others?
Kardashev Scale - https://news.ycombinator.com/item?id=40327782 - May 2024 (28 comments)
Kardashev Scale - https://news.ycombinator.com/item?id=27067895 - May 2021 (5 comments)
Classifying Civilisations: An Introduction to the Kardashev Scale - https://news.ycombinator.com/item?id=26108947 - Feb 2021 (1 comment)
The Kardashev Scale - https://news.ycombinator.com/item?id=24084021 - Aug 2020 (1 comment)
Nikolai Kardashev (of Kardashev scale fame) died - https://news.ycombinator.com/item?id=20619494 - Aug 2019 (1 comment)
Kardashev Scale - https://news.ycombinator.com/item?id=20603386 - Aug 2019 (31 comments)
Kardashev scale - https://news.ycombinator.com/item?id=2183106 - Feb 2011 (15 comments)
He says he has a hard time beating his feather in arm wrestling despite him working out. Anecdotally blue collar people have much strong wrist flexion (cupping) than us white collar people, but pronation and technique can help negate that. My experience shows that power cleans can help with arm wrestling but not many people do those.
Yeah, arm-wrestling is kind of a specific skill that isn't covered by most "exercise" (including strength training) unless you are specifically focused on it. It's like notorious for skinny-looking specialists being able to best jacked non-specialists.
Be hipster type II civilization brain in a jar. Wonder what it's like to have muscle / strength train. Incubate a body, start lifting.
I recently re-read Frederick Pohl's Plague Of Pythons which I will try hard not to spoil for you. In it there is not only the most evil set of villains that I've ever seen in science fiction based on dear Tellus, but they suffer muscular atrophy too.
"Plague of Pythons" is available (for free) on Standard Ebooks for anyone else interested in reading it:
https://standardebooks.org/ebooks/frederik-pohl/plague-of-py...
Sounds like an interesting book, added it to my reading list.
"Gateway" by the same author definitely worth a read, too.
He probably should worry about our brain atrophy sooner than our muscles.
When we get to that point we will have the right methods to sculpt our bodies as we like. It's a matter of hormones or some other biological hack.
There's no guarantee of this. It's quite possible that muscle and bone cells require the stress of weight loading to develop properly and that there's no simple hack to make them do it without that response.
Absolutely correct.
Traditional office culture makes it very difficult to get a proper workout in while, at the same time, confining you mostly to your chair, hunched over a desk (and/or craning over a small screen), to view things on a screen that eats away at your eyes by default.
WFH made this worse. I've worked with so many people that start work at 0700 and end at 1700 or later.
Add shitty, cheap food, 2.5 kids and a partner in there, and you're basically on an express train to bad hips, bad knees, poor health markersa and immobility at (not so) old age.
"Work out during your lunch hour," you say. The author spends a lot of time on muscle use. Powerlifting workouts require lots of rest between sets, especially as you get stronger. Spending 2h on a workout is normal in powerlifting. Not happening during lunch hour, not like this matters because someone will just schedule a meeting over it anyway.
"But I wake up at 0400..." No. Just no. (A) A parent with two and a half kids is not getting up at ass o clock in the morning to chase that pump (or work out to stay healthy) when their kids are gonna wake them at 0640, and (b) this is an awesome way to either sleep like shit forever or incinerate the last fledglings of your social life.
All this aside, the farmer life is a super hard way to live, . Overuse injuries are very common. However, we went the complete opposite direction in building today's office culture, and it's a real shame.
If society ever developed along the lines proposed, which is highly improbable to begin with, then speaking of humanity as a whole is a complete nonstarter.
We'd naturally fork, because that future sounds like a dystopic hellscape to many (if not the overwhelming majority).
And indeed once we reach the point of being able to reliably colonize other planets, large scale splintering (both physical and cultural) will begin near immediately. You'll have libertarian planet, Islamic planet, even the Mormons will finally have their planets! And so on.
And the people who want to sacrifice their bodies to go enter the machine will certainly have their own little slice of the universe as well.
In the excellent very hard sci-fi novel Diaspora by Greg Egan humanity has split into 3 main branches that don't really trust each other much.
biological humans, which are subdivided into various genetically altered varieties and the original unmodified humans.
nuclear powered humanoid robots that are not allowed on earth but are perfect for working in space.
fully simulated humans being run on nuclear powered computers buried deep underground for security. Their minds run 700 times faster than normal humans.
This feels pretty plausible to me.
Can't wait for the Rastafari planet
getting splintered metaverses seem way more feasible than splintered physical planets
You have to have everyone go into the splintered metaverses to avoid physical expansion. Everyone. Every biological body. Every AI. Every AI written for the specific purpose of having a long enough time horizon to settle new locations physically. Even the AIs written specifically to marshal together the physical resources to build more metaverse computing power. Even the AIs and fiesty biological bodies who one way or another end up with a 100% bias towards physical reality. Even the many, many beings who will quite accurately observe that no matter how short-term appealing this is a long-term loss. Even the beings who specifically want to be the ones in charge of the physical machinery and see an advantage to continuing to expand it. Every. Last. Being.
I don't think this degree of uniformity is plausible.
I reject this as an explanation for the Fermi paradox for similar reasons, except they're even more relevant across all of the putatively common alien civilizations. I don't even find it plausible that all of human civilization would do this, let alone all of every civilization ever.
I couldn't agree more, but with one exception. I tend to heavily indulge the simulation hypothesis, but the nuance here being that it's not necessarily just an arbitrarily simulated complete reality.
Our lives do an unbelievably good job of teaching us endless unteachable lessons. What if life as we know it is, for instance, little more than a day's lesson in another reality? Or a day of a gaming? Perhaps a test of character for some sort of role? There's no reason to assume time, and life expectancy as we know it, are universal truths. Even within our own reality the rate of the passage of time is variable.
The only problem I have with the simulation hypothesis is it being turtles all the way down. Imagine you pass from this world only to 'awake' in another. How does the exact same simulation argument not just apply yet again? It seems fundamentally unfalsifiable and circular, but I suppose that is standard for any explanation of life.
I believe this is actually one of the strongest arguments for the simulation hypothesis. If simulated worlds are possible then there are almost certainly more simulated worlds than non-simulated worlds (of which there can only be one) so therefore the odds of existing in a simulated variety are never less than half and likely much higher or else simulated worlds cannot exist with enough fidelity to remain undetected.
I think the last part is the problem with this argument. We can already simulate worlds (Minecraft), they're just very different from our own. It has to be possible to actually simulate our universe. Not just theoretically, but also practically: Someone needs to have enough energy, time, engineering ability, other resources, and enough motivation¹ to run the simulation.
Also, if you permit me to get spiritual for a moment, I believe that it could be theoretically possible to simulate any fully materialist universe, but I'm not convinced consciousness can arise from doing maths. Since I am conscious, this universe must not be simulated, no matter how many simulated worlds actually exist.
[1] I'm assuming that most creatures intelligent enough to understand the concept of simulating a universe will want to try it. But if it takes an entire civilization to do so and that civilization has to choose between, say, spending the energy on simulation running or on food production, it's pretty clear what will happen.
Then you get a Chicxulub and it is all over.
Physical health is directly correlated to mental health, if anything we'd all be jacked to the teets
I need three hands so that I can hold my smartphone at alll times
Why do we use weird arbitrary milestones like the (logarithmic) Kardashev scale. It adds literally nothing useful to otherwise fun conversations like this.
Jargon is often used for in-group signaling.
Yes. "Kardashev Scale" has now become a slop indicator.
Interesting blog post. I think the majority of what you see is that due to how rapidly technology and other fields have bloomed via human involment, and due to how we have become an interconnected society due to the industrial revolution.
I think that the major way humans cope/tackle this is via specialisation. While not for everyone, most people seem to find a job in a field, and the work in that field helps us support a more complicated society than we can fathom. Most people can't memorize all the stuff from multiple domains, or they would burn out. Most people don't understand how truly complex a semiconductor is, or how electricity and power is generated, or how to design a car. These are just basic examples but I'd argue a really good example of how humans have chosen a specific domain or thing and over time developed better understandings of the field and topic. The average person could do any job I'd argue.
We are not as physical as we used to be, we have "engineered" ourselves replacements. The tractor, the car; both replaced horses but at the cost of needing someone who understood the principal of the new technology.
Be it robot workers replacing amazon warehouse employees, or the tractor that improved the farmers ability to harvest or plant crops; both required smart people to not only develop them but to maintain them.
I'd argue while we really are less physically active, due to technology and general advancements we have made over the years; this comes at the cost of mental strain. We mentally must process and think more than ever before, pushing our brains to keep up so we can stay relevant.
everyone knows our future is predicted by Wall-E
In another vein, technology could also help us perfectly fit bodies by altering our cells at a molecular level. But if there is no need to move to contribute to the economy, why would anyone do such an expensive thing?
Because it's nice to have the strength when you need it. Also, it protects your body. I developed a bulged disc in my neck from decades of spending too much time at a computer. Muscular balance and variety of movement is critical to maintaining a healthy body. Not to mention benefits like lessening injuries from accidents.
And it is not even expensive to a full type 1 civilization on the Kardashev scale. We just need to hack some genes to not require exercise to develop muscle mass. We already can do it with drugs, and we probably could do it genetically if it wasn't for safety and ethical concerns. As for the cost, I expect a Type 1 civilization to be able to fix genetic diseases as a routine operation, and they could fix muscle atrophy at the same time, if desired.
Muscle mass requires more energy, but by definition, a Type 1 civilization has no shortage of it. And I expect making food out of thin air (like plants do) would be the kind of technology such a civilization would have.
Also because physical attributes are a key component of attractiveness, regardless of their actual utility.
We're not just economic units. We eat, we love, we breathe fresh air, we sleep. Even in a far-flung future, if we are still human, we are still animals.
While its fun to explore ideas, this post commits the intellectual sin of simple extrapolation-ism when everything is just oh so much more complicated than that. As others are pointing out here in the threads, biological interventions for physical strength are inevitable.
This stands to reason once you mentally discard exercise as a pre-requisite of strength. An elephant is strong, not because it exercises, but because of the biological mechanisms e.g. genetics that says: grow big, grow strong, and the effect size of those mechanisms are much much larger than individual differences due to exercise. It is clear, at least to me, that the need for exercise for adjusting strength has more to do with not spending extra energy building a body that has high upkeep if it isn't needed for survival.
I don't know, to me it seems like biomedical engineering and manipulation will take off and develop a lot sooner than people willingly "upload" their minds to a machine – itself a dubious idea full of problems. I think it's far more likely that current-state humans won't be exploring the stars, but a genetically modified version of them will be.
I think there is much less angst regarding the idea of upgrading humanity piecemeal, a la the Ship of Theseus, than there is to fully discarding one's body for a digital existence. This has already sort of happened over the last few hundred years with the concept of transplantable organs. Prior to the widespread acceptable of the interchangeability of organs, it was not uncommon to think that your self and body are unified and linked in a way that implied organ transplation was problematic or undesirable.
And on that note - is it just me, or are biological visions of humanity's future fairly scarce in sci-fi and in futurism (another name for sci-fi)? My guess is because such topics seem dominated by software engineers, physicists, etc. that are less interested in biology.
Tech can surely overcome muscle atrophy if it was a real issue. Do we even need muscle if we add more powerful add on to walk for example? I would argue we want to keep muscle because we can have very precise control and feeling, unless the new stuff can make it even better.
Sounds a lot like slavery.
The ideal towards which we all strive is, of course, the Dalek.
I’ve been wondering if a similar phenomenon will be observed with our mental muscles. Will future generations know how to write a coherent e-mail or essay? Will they know how to approach solving a complex problem without AI assistance? Will doodling in class be supplanted by Midjourney prompting? Why bother thinking too hard when the machine can do it for you?
When we are all immersed in the substrate of AI, will there be a gym equivalent for the intellectual?
...So I'm advanced?
This means I'm advanced.
Stupid premise.
We already have exercise mimetics in pre-clinical trials. If you can keep yourself fit with zero expenditure of time, why wouldn't you?
The joy of motion and physical effort.
The parent means "why wouldn't you stay fit (either manually or with drugs)" rather than "why wouldn't you do it with drugs".
Because some of us have high levels of skepticism with that stuff. Even the GLP-1 inhibitors are too new to really get a handle on. The only proven methods to health are those that have existed before we ever came along: a clean diet and (good) exercise.
History shows time and time again that there are no free lunches in nature.
Do you have any useful search terms for them?
"Exercise mimetics" are fine. You need to look at the professional publications. It's a very active area of research, so things change rapidly.
The newest research: https://jpet.aspetjournals.org/content/388/2/232.long
Here's a nice, but a somewhat obsolete review: https://pmc.ncbi.nlm.nih.gov/articles/PMC8728540/
i assume EMS (electrical muscle stimulation)
No, exercise mimetics are drugs that stimulate the same biochemical pathways as regular exercises.
Sometimes I think that is what metformin and statins do, because weirdly enough both seem to blunt the exercise response. I’d love to take them but I already exercise.
Maintenance of one's muscular-skeletal system is a Goldilocks problem. Too little exercise leads to atrophy, but too much also leads to degeneration. Eg the productive lifetime of slaves in the labor-intensive Caribbean sugar plantation system was only about 10 years. Breakdown of joints, ligaments and tendons was a common problem related to overwork (and is commonly seen in athletic training today).
Similarly, my understanding of the history of yoga in India is that it was introduced because of the sedentary lifestyle of the Brahmin caste, and much like with office workers today in the USA, it served to keep them in decent physical shape.
Bold of them to assume we’ll survive the century at any level above the Iron Age, and with any population above the high millions to low billions.
Capitalism is keeping us locked into the “Business As Usual” model that will bring us to civilization-destroying climate change by the middle of the century, and with tropics-denying lethally high wet bulb temperatures that will get well into the temperate zone by the end of the century. Think most of CONUS being uninhabitable for multiple days to weeks every year, with or without AC.