# Why do we keep smoking in distant future?

You gotta admit. That roguish guy you just met at space bar looks cooler with cig in his mouth. Not only he always shoots first, but also he manages to do so while puffing awesomely looking clouds of smoke.

The problem is obvious. This is not galaxy far far away, nor long time ago. It is our solar system, circa 2100 CE.

Even bigger problem is, that in year 2016 we know that smoking kills. No matter how cool you may think you are going to look, its not worth the lung cancer. And it does not stay here, inside European Union we are putting really awful pictures on cigarettes:

Warning, graphical content below. Proceed at your own risk!

Translation: Smoking causes heart attack

Assuming realisticly-optimistic scenatrios, we made it to year 2100 without losing knowledge how harmful cigarretes are. Yet, at least half of modern population keeps smoking.

Why?

P.S.: I am not affiliated with any tobacco company

• Comments are not for extended discussion; this conversation has been moved to chat. – Monica Cellio Dec 21 '16 at 4:39
• We've known smoking kills since the 1950s and yet we're still smoking, even those of us born after that was discovered. What makes you think we'll stop by 2100? Especially if smokers are still considered as cool looking as you say... – colmde Jan 16 '17 at 11:20

## Because it's fun?

Basically the same reason as today, even now we know it's harmful. The thing is when a child is born in 2100, it's not like they're influences by 100+ years of scientific research, it's just what they are exposed to in their lives, which would be about the same amount we are used to now probably (assuming the financial interests stay roughly the same, i.e. unhealthy things are still profitable and legal)

Also:

• medicine might be much better then, so you could just replace your lungs at some point if they're ruined. This doesn't rule out people dying from cigarettes, but it gives them all the more excuses to keep smoking.

• Moreover, cigarettes might be much better than other substances. Weed could be legal along with various other new substances which may be less dangerous due to the advances in medicine. So not only would it be safer, it could also be more fun.

• But "we", taken as the majority of the population, don't smoke now. (See the link in my answer, giving smoking rates in various countries.) Even in the 1960s, when tobacco advertising was still a major factor, less than half the US population smoked. So to get a large smoking population in the future, you somehow have to completely change current attitudes. – jamesqf Dec 18 '16 at 6:40
• Who says it's tobacco they're smoking anyway? We're already starting to legalise weed around the world... – Sobrique Dec 19 '16 at 9:19
• @jamesqf Is that less than half the total population, or the smoking-age population? – MissMonicaE Dec 19 '16 at 13:16
• @MissMonicaE: Smoking age. I believe (without re-checking) that it's variously defined as over 18 or adult in the links in my answer. Also note that (unless I missed one) even in those 3rd & 4th world countries where more than 50% of men smoke, less than 50% of women do. – jamesqf Dec 19 '16 at 18:00
• @Sobrique Excellent point, but while we're at it, I doubt smoking in the sense of combustion and inhalation will stay in style. – Amani Kilumanga Dec 20 '16 at 1:51

We are currently spending an awful lot of money trying to cure cancer and by 2100 or whenever you feel like setting a space opera, there is a reasonable chance that we will have it figured out and that curing cancer will be somewhat trivial.

When that happens, the negative consequences of smoking don't matter as much and we may as well start smoking again.

• Of course, even if they aren't dying from cancer, smokers will still stink. – Jack Aidley Dec 18 '16 at 11:56
• Well, "lot of money" compared to your household budget, not exactly a lot at all when compared to the household budget of states... the value of one human life according to EPA (US health agency) is $8.4 million, so it's just not economic to spend too much on cancer research. – Nobody Dec 18 '16 at 18:21 • @Nobody the value of one human life according to EPA (US health agency) is$8.4 million What's your source, or caveat on that? I find it impossible to believe that anyone values the life of say, a sub-Saharan subsistence farmer at 8.4 million, though that's probably not much of a stretch for the valuation of a camera-friendly, middle-class, white American. – HopelessN00b Dec 19 '16 at 9:57
• @HopelessN00b Easy to find, for example check Wikipedia's sources, or the sources of xkcd money plot. It's an American life, I don't think they have numbers for non-American lifes (probably depends mostly on the expected political backlash, sure to be much lower). – Nobody Dec 19 '16 at 10:03
• In addition to cancer being cured, maybe there's some new 22nd century disease come along, which doesn't have a cure, for which smoking is a suppressant. – anotherdave Dec 19 '16 at 19:31

# Benefits Worth Early Death

I'm assuming that the "it gets me high" option isn't valid in the future... we're already finding much better drugs for that sort of recreation. So... we need some other advantage. Such as...

a) Positive. Or the chemicals coat your lungs to keep the augmentations in your lungs alive so that the next time you're underwater, you can still breathe. If you didn't smoke, those implanted augmentations would wither away, leaving you just another land breather.

b) Neutral. The cigarette smoke will kill you. But in the meantime, the chemicals in them keep your lungs free of the alien virus that is ubiquitous on the station but only lethal to the small percent of the population with genome X.

c) Negative. Or the chemicals suppress the fungus that is growing in your lungs. Humans sometimes contract it. It's lethal. So you smoke to keep it from growing more. If you stop smoking, you'll actually die faster.

Basically, you're looking for some sort of chemical effect on the lungs that makes it worth it.

• If you want a more dreary option, maybe there's just so much pollution that smoking or not smoking makes no difference to your health. Or maybe the smokers are in a profession where they don't expect to see their fiftieth birthday either way. – user2727 Dec 19 '16 at 9:33
• Great answer. And then smoking can be badass again: either the smoke is so adventurous he needs the lung augmentations to breathe under water; or travels so much to alien worlds he is at high risk of contracting the lung fungus, yet keeps going. – Francesco Dondi Dec 19 '16 at 14:10

"Yet, at least half of modern population keeps smoking."

Assuming you're talking about the US, that just isn't so. Per the US CDC, it's been more than half a century since half of the us adult population smoked, if indeed they ever did. http://www.infoplease.com/ipa/A0762370.html Currently the rate is well under 20%: https://www.cdc.gov/tobacco/data_statistics/tables/trends/cig_smoking/ and still declining, either through current smokers quitting, or old ones dying off and younger people not adopting the habit.

Haven't found historic data for the rest of the world, but per Wikipedia, probably no country currently has an adult smoking rate of 50% or more: https://en.wikipedia.org/wiki/Prevalence_of_tobacco_consumption#2008_data It's difficult to be sure without doing more math than I care to, because the rates are presented separately for men and women. Even where more than 50% of men smoke, less than 50% of women do.

Bottom line, if nowhere near half the population smokes now, you obviously can't have half of it KEEP ON smoking. In order to get a 50% smoking rate in 2100 CE, you'd have to come up with some plausible reason for there to be a MAJOR change in public attitudes. As for instance your statement that "That roguish guy you just met at space bar looks cooler with cig in his mouth" just isn't reflective of current attitudes. I admit that I'm not exactly au courant WRT popular culture, but as far as I can tell, most people consider tobacco smokers to be low-life losers*.

PS: Link to study of public attitudes towards smoking bans, one of a great many: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3845040/

*Anecdotally, the only person I know who smokes is my neighbors' kid, who has spent most of his adult life in prison.

• Good info, but this doesn't really answer the question. – ApproachingDarknessFish Dec 18 '16 at 0:27
• Not sure why you'd assume the OP is talking about the US when he says "inside European Union we are..." – zeta Dec 18 '16 at 1:19
• @sumelic: I assume the US because I live there, and it's easier for me to find statistics about it. (And also because EU doesn't have much of a manned space program :-)) However, from having lived there (and in Switzerland) for a couple of years, most recently in the mid-2000s, I believe European attitudes aren't that much different from the US. As for not answering the question, how do you answer a question that's based on a false premise? You can't: you have to explain to the user why the premise is wrong, and unfortunately you can't always do that in a comment. – jamesqf Dec 18 '16 at 6:27
• @jamesqf There is a European Space Agency! And they are sending people to space... They're just borrowing somebody else's rocket. And rocket launcher. And land to launch rockets on... – wizzwizz4 Dec 18 '16 at 12:29
• @wizzwizz4: Then again, the US doesn't presently have manned launch capabilities either. – brendan Dec 19 '16 at 16:19

Perhaps motivated by lagging sales and government pressure big tobacco finally gets around to producing cigarettes that are every bit as tasty and addictive, but substantially less or even non lethal. Overnight millions of anxious, agitated former smokers light up again.

Corporations become more powerful

The triumph of falling smoking rates has come, largely, because governments have been able to reign in corporations who profit from addiction and suffering. All it takes to reverse this situation is for the Tobacco companies to gain strength against governments so they can convince people that the risks of smoking are exaggerated, uncertain, or complete lies.

People become more disillusioned

Assuming realistic levels of automation it's really quite likely that a large slice of the population will be unemployed in the future simply because there aren't the jobs. This kind of future may lead to large numbers of people feeling pretty hopeless and that, in turn, will lead to higher drug consumption, including - of course - tobacco.

I'd propose two reasons:

## Human nature

A rather controversal view of things, but it's always been human nature to take one or another form of drugs. This goes for tribes deep in the rain-forest 1000BC just as for most modern day cultures. There are of course exceptions due to religion (classical example Mormons), but for our general person this usually applies. Just like smoking, alcohol and coffee are the standard-drugs nearly anyone in western societies takes (this list could be expanded quite a bit). What is consumed is a social topic, so I don't see any problems in reasoning that people won't stop smoking in the future. As for the health problem: it's widely known that drugs in any form are bad for our health in one or another form, but people simply don't care - at least until it's a bit late. I don't see why that should change altogether that fast.

## Lobbyism and social acceptance

As mentioned above, it's quite unlikely people will stop taking drugs. This is why the sort of picture you showed in your question exist. Instead governments will try to prohibit or otherwise restrict consumption, except for some largely established cases. Luckily any larger sector of the economy can use lobbyism to avoid getting it's product prohibited. And at some point people are just that used it that they simply won't care at all. As an example: quite a lot of people don't even consider alcohol a drug. So the tobacco-industry will go this path and simply try to increase social acceptance and it's influence on politics (and has done so in the past). There have been a few minor countries that did prohibit tobacco/cigarettes (Bhutan in 2004, Turkmenistan in 2016, ...), but it's doubtful whether this will become global at any time. On the other hand a large legalization movement is on it's way as well (Netherlands, Portugal, etc.). While this doesn't aim at tobacco, as it's already legal, it's doubtful those countries would go the exact opposite way and prohibit tobacco while making everything else legal.

In general keep in mind that it's rather unpredictable, which side will win on this topic. Thus: either just go for the alternate universe, where people simply didn't stop smoking tobacco, or last but not least: go for

## Alternatives

I guess everyone of us has seen some guy using a vaporizer. Just add a bit of sci-fi to a vaporizer, and there you are with a cigarette-sized vaporizer. Now why would your protagonist use one of these?

• He might like it
• He's aware of how badass it looks and is a bit self-regarding
• The vaporizer provides some useful functionality. Probably it's just the asthma-spray of the future?

An alternative could look like cigarettes that don't cause cancer and other health-issues or better medicine that is capable of healing the damage done by cigarettes.

EDIT:
If you'd rather go for a bit of a darker setting, this could also work: Smoking is quite addictive and there are statistics that prove (controversial, but let's just assume they do), that this is also inheritable. Add an additive to cigarettes that increases this effect and you'll have babies that are born addicted to nicotine. Trying to get those poor sobs away from smoking might be just hard enough to prevent tobacco from getting prevented from that point on, simply because an addict will find a way of getting what he needs anyways.

## They are not smoking

At least, not some leaves filled with poisonous compounds like nicotine and thc. Who would be stupid enough to do something like that, anyway?

Those wraps of paper that people burn and inhale from are made from 100% harmless material, and they do serve to (chose whatever you like):

• clean the lungs of dust and particles, improving the recipient breathing capabilities (yes, there are machines that do that, to, but this smoke is way less agressive and you can take it wherever you like).

• a mystical moment to all of the followers of the MarlCamWins faith, similar to a prayer in other religions, and that also allows the belivers to identify each other.

• a harmless source of smoke to allow the public to indulge in creating phantasy patterns with the exhaled smoke. Kind like someone playing with a yo-yo in his free time.

• a public sign that the people smoking it can affor the 10.000 credits it costs (about the pay of month of unskilled labour).

• depending on the color of the roll or the joint (or even the color of the smoke), a cigarette is used to make an statement (think of "I voted" badges, blue ribbons, etc.

• Yeah, the problem with that is you may as well call them magic cigarettes, because that's the only way to make them do what you suggest. The by-products of low temperature oxidization of organic matter necessarily include a number of toxic gases and particulate matter. It simply can't be made healthy, so long as burning is involved. – HopelessN00b Dec 18 '16 at 23:45
• @HopelessN00b "Sufficiently advanced technology is indistinguishable (btw, what a word) from magic" :-D. Anyway, it is a good point to be taken in consideration by the OP – SJuan76 Dec 18 '16 at 23:48
• "who would be stupid enough to do something like that anyway?" How about up to one billion people or 20% of the world population (2014).. en.m.wikipedia.org/wiki/…. ok not all knew it was poison, but plenty do and smoke anyway. the vast majority of smokers in the west know its bad for them and do it anyway. kids know its bad and still start. – Innovine Dec 19 '16 at 17:25
• @Innovine You're right, there are a lot of stupid people in the world. – Samuel Dec 19 '16 at 23:17

Are they smoking, or are they just inhaling recreational drugs? Honestly, the idea of people actually burning dried tobacco leaves as a method of inhaling nicotine in the future seems far-fetched, in no small part because we have a better way now - "vaping". And if you want, you can even puff out cloud of vape, if you think that looks cool.

As much as I agree with the other answers which point out that people do all kinds of things that they know are bad for them, and that's not going to change, inhaling drugs by burning dead plants is unpleasant, inconvenient and a just plain inferior way to get your fix. (I say this as a former smoker who now vapes.) There's a long list of inconveniences and hazards that arise from setting your drugs on fire in order to get them into your lungs, and I don't see that method persisting much into the future when there's already a widely adopted method that's better in every way, right now.

I would submit that the half of the population that still inhales nicotine does it with some form of vaping mod, rather than flammable sticks of dried nicotine. If you are particularly attached to traditional smoking, you could use economics - a good vape setup costs at least a hundred dollars up front, compared to several dollars for a pack of cigarettes, so people who can't afford the upfront cost smoke traditional cigarettes, while the rest vape. I suppose you could also extrapolate out the current anti-vaping efforts in some countries to a ban or other restrictive regulations on vaping products, though it might be tough to explain why more dangerous cigarettes didn't get similar treatment.

Either way, the reasons people use recreational drugs of any sort are fundamentally unchanged since the dawn of time. (There are literally thousands year old warnings about opium use in Ancient Greek texts, and people still use opium, and stronger opiates today.) It feels good, so to hell with the consequences. There's more to life than maximizing how long we get to live, and most people would rather live a shorter life they enjoy than a longer one they don't.

• The question, though, is whether tobacco, or just the nicotine, should even be considered a recreational drug. Maybe it's a matter of individual physiological differences, but it doesn't, as far as I remember from my youthful experimentation with it, give you any sort of buzz at all, unlike some other smokable plants :-) – jamesqf Dec 18 '16 at 19:32
• @jamesqf Well, it's a drug... and people use it recreationally, so I say it should qualify as a recreational drug. As to the effects, if all you've done is smoked tobacco, it's hard to say, since nicotine isn't the only chemical in tobacco smoke that has an effect on our physiology, but since millions of people use both nicotine in the form of vaping and in the form of burning tobacco for recreational purposes, seems like they both qualify as recreational drugs. The only question is whether they're significantly different to qualify as different drugs. (I would say so, but it's debatable.) – HopelessN00b Dec 18 '16 at 21:15
• Ok, let's substitute 'psychoactive' for 'recreational'. As far as I recall, tobacco had no discernable psychoactive effects at all, unlike a certain other common smokable substance. Or alcohol, or various other things. The only attraction seemed to be social, and that's suffered a major decline due to changing attitudes. – jamesqf Dec 19 '16 at 4:52
• It does have effects on the brain. It makes you a bit more wakeful and calmer. But those effects are not very strong compared to other psychoactive drugs. – user2727 Dec 19 '16 at 9:38

Rebellious attitude

Growing up means that you sooner or later need to find an own way of living. Part of the process is the disillusionment of your parents; even if you have good and caring parents, your view as a child of "father knows everything, mother is the best" will be sooner or later replaced by a more...realistic viewpoint. Then in puberty your body and mind urges to explore your environment and create changes in the world, the former environment is now found stifling, suppressive and boring.

So searching an own way is necessarily breaking apart from the old way: it is no surprise that you judge your behavior not by looking how rational it is, but how revolutionary it is and how positively and impressively it is viewed by your peers. Breaking rules is a sign of independence and nothing is better to tick your parents off than risking your health and life.

That means high-risk behavior: smoking, drinking, sex, shoplifting, gambling, driving recklessly, more sex, taking harder drugs, running up debts, brawls, hazardous sports, adventures. 18-25 is an age which is known for high risk behavior of all kinds, a simple Google search with "adolescent high risk behavior" will turn up a staggering amount of data.

In fact I think if something would be shared by the absolute majority (imagine 99% smokers) and is not associated with "unmanly/unwomanly" as stigma, the youth would be doing exactly the opposite (being non-smokers).

Some people do find their environment so stifling that they contine to be rebels past their 20s and will stick to their behavior.

Why smoke in the future ? The future is grim and dystopic.

One of the triggers which makes reckless behavior reasonable is if your future has a good chance of not existing at all. In war time young people plastered themselves to unconsciousness and had sex with everyone they could get hand on because it was likely that this was their last chance to experience life.

So put in overpopulation, disease, high unemployment etc., everything which makes planning a "normal" life ridiculous and you will have a convincing argument for high risk behavior.

You cannot believe anything you hear in the media anymore. There's "proof" for everything due to a huge propaganda industry.

Right now you're told who to vote for, what products to buy, what to listen to, what to watch, what to eat and drink. You're told who the good guys and bad guys are. It used to be the victors who wrote history, but in todays post-truth society it's the rich, corrupt and/or evil who paint their version of truth onto not just history but current and future events.

Tobacco is big business. They already spend vast sums of money to encourage subtle product placement and influence opinion... the OP starts with "That roguish guy you just met at space bar looks cooler with cig in his mouth".... that attitude was paid for by tobacco companies, and it was not cheap.

In the future, propaganda and subtle mind control will be even more highly developed science than it is now. Consumers will continue to smoke, because they will have been manipulated into thinking its cool, because they don't believe it's bad., because they know one cig doesn't get them addicted, because everyone else does it so there must be some benefit, because they feel immortal or that cancer happens to someone else... all the reasons people smoke today, even though they know its bad.

The difference in future society will be that the health effects will be discredited, counter proofs proposed, science will be laughed at and ignored, and fact-checking pushed aside. Look at Creationism, and now imagine that level of ignorance being supported by multi billion dollar industries.

I would pose the question, "Why did I start smoking?" After all, I started smoking some 16 years ago, knowing full well there were absolutely no health benefits but MANY negative health risks associated with it. It wasn't even a matter of opinion; I'm nowhere near old enough to have lived during a time where this was even in question. Smoking was and is DEFINITELY bad for you, in no way good, and this wasn't top-secret information.

Of course, without getting into details I know nothing of (social factors, economic factors, gender, race, etc.) a simple answer is, "because I wanted my friends to THINK I was cool." Sure, I can see how stupid that was now, but in the adolescent mind those things don't "click," and there probably lies part of the problem: most people that smoke don't take it up after their teenage years, when the brain still hasn't developed completely, puberty exists, and doing reckless things for, "street cred" is far more valuable than doing things for the long-term benefit of yourself.

You could also ask, "Why do you continue smoking?" Good question. I guess because it's almost ritualistic. I wake up, the first thing I do is grab a cup of coffee and a cigarette. I eat, I want to smoke after. I go on break at work, that break must involve a cigarette with my other smoker peers. I can't explain it in any depth, but maybe that helps. It's one of those things where it shouldn't be there, but my day will feel "off" if it isn't.

In no way am I suggesting anyone should, or that it's cool, or that you should give it a try: you most emphatically should not, it is not, and you should not. But if you want to know why smoking has a good chance of existing in the future, you really only need look to the present: we've known it to be harmful for more than a few decades now, but people have continued to do so, and have even unfortunately recruited new faces. Thankfully, as has been said, smoking (at least in the US) is on a serious decline, possibly due to the advertising regulations and taxes imposed on tobacco. I'd like to think that if I had better friends, Camel Joe didn't make it seem so "cool," and cigarettes cost \$6.50 a pack when I was younger, maybe I wouldn't have either.

Governments stopped pushing against

Western governments fight a long battle against smoking, with plenty of propaganda showing its harms, forbidding tobacco companies to put their own ads and discouraging through taxes.
Why would they try to kill a profitable industry like that, though?

Well, simple: Smokers are very expensive for the healthcare system. All those cancers, with their chemo, radio and transplants cost a lot, more than what govs get through taxes.

If a laissez-faire wave sweep through the West and sacrifice public healthcare to the altar of Free Market to never come back, the govs would lose the economic factor to fight tobacco. After that, it's just a marketing effort.

Because we love and admire our grandparents, who loved their grandparents, who also loved their grandparents [my redundancy is expressing generations], who loved their grandparents who may have been native americans smoking tribally. It could also be that hundreds of years of smoking effected our genes in such a way that we still feel we need it. I imagine that deep in the not too distant future we'll genetically alter a strain that causes less harm, if any, which becomes the norm.

# Non-carcinogenic, genetically modified tobacco

This one could be rather simple. With enough futuristic handwave technology, tobacco could be genetically engineered to be non-carcinogenic, allowing smokers to puff away for decades without any significant cancer risk.

Your lungs might be shot after a while, but who cares?

## Cancerless cigarettes!

• This is touched upon elsewhere, but since your answer is just the one point: It's not the tobacco that is carcinogenic, it's the smoke. – Reinstate Monica -- notmaynard Dec 19 '16 at 22:30

Its an intentional anachronism.

Our antihero considers himself a puckish rogue, or is obsessed with early 20th century noir cinema. Smoking isn't an affection in its own right - its part of the image our gunslinger has, maybe he wears a cowboy hat and has a sixshooter in an era of high capacity, caseless ammunition, or wears a suit.

He knows those deathsticks can kill him, but so can his lifestyle. He knows its not the bullet with his name on it that'll get him, its the one that is addressed "To who it may concern".

A good example of this in fiction would be Lester Tourville, whose tendancy to smoke cigars (under the air intake!) was seen as an eccentricity which was part of his wider public persona.

As part of charecter building - its something for other charecters to remark on (and possibly could be part of a plot - where does he get those damned cancersticks?).

## As a status symbol

I can't remember where I read this (it was either the Eclipse Phase universe or the Android universe), but either way smoking became a status symbol among the hyper-elite. Practically all the hypercorp executives and oligarchs in-verse were chain-smokers, just to show they were so incomprehensibly wealthy that they could absolutely wreck their organs with well-known unhealthy habits and have their ruined organs/whole bodies replaced with fresh ones the same way the average human changes their underwear.

Maybe in your 'verse, people smoke cigarettes to show the quality/augmentations of replacement lungs, 'look, I can smoke these all I want and my lungs can handle it with no ill effects, thanks to nanotech/gengineering/cybernetics/etc', or maybe it's just to show that they have the nigh-unlimited capital at their disposal

Because smoking also kills the rare lung-dwelling fungus that is killing space-faring people

or

Because 3d-printed cyberorgans are cheap, making most illnesses irrelevant

or

Because those are holographic cigarrettes

or any other hand-wave to justify something that would be very impractical for space travel, since fire + smoke on spaceships would be a far greater risk to space travelers than cancer or any of the other health issues related to tobacco.

The again, you could just say that tobacco is a retro fad done for coolness sake, and that the combustion of space-approved cigarettes is non-toxic.

# Because we have to.

In Screamers (1995), the world has been ravaged by nuclear war. Anti-radiation medication takes the form of cigarettes (for some reason).

# Because we have beaten cancer.

In Transmetropolitan, gene mods are cheap and plentiful, and the anti-cancer trait appears easy enough to come by, so you can smoke all you want.

Summary: there is a poorly identified reason that likely contributes to people who "ought know better" smoking tobacco which is often absent from discussion on the matter: self-medication to an unknown end.

I am a current smoker who thinks it a nasty, socially obnoxious habit of no apparent benefit and clearly identified risks. I have quit, with little effort or side-effect for years at a time and have voluntarily chosen to begin again despite its myriad unequivocal risks and unpleasantness, I've obviously thought much on the topic. What is often ignored is:

# the benefit of smoking

There are a some things we're pretty certain of:

• The risks and costs
• The weakness of nicotine as a psychotropic
• The demographics of smoking in the US: 1) the poor 2) artisans

Demographic (1) is easily explained by other answers here: propaganda, corporate exploitation of the ill-educated, and so on. What I've not seen here is an explanation of demographic (2): educated, rational, people who opt to smoke given all the reasons why they know they oughtn't; that is, people like me. "Habituation" is a sufficient explanation for much of this but I think there is an ineffable benefit that keeps my demographic puffing toxins. It is a form of self-medication.

Studies[citation needed] have shown that smokers are uncannily skilled titraters of their blood nicotine level. Here I resort to conjecture: there is a yet-to-be-identified self-medicating brain-state modification that smokers find beneficial. I am a practical artist, in software, but it is a creative endeavor analogous to that of a plastic artist such as a painter: I am engaged in transforming thought into a fixed, physical manifestation just as a painter. We have only vague notions of the dopamanergic effects of nicotine and almost no understanding of how such manipulations affect anything. Regardless, the prevalence of smoking in the creative fields is too large to be ignored. I put forth the proposition "smokers alter their brain chemistry in a subtle way that promotes their activities" .

This is not sufficient explanation; all the factors in the other answers apply. But I don't know that there is compelling evidence to reject my conjecture out of hand. Worse still, I can conceive of no test that would serve to refute or support the the conjecture. Neurobiology is an infant science by any measure and does worst in the face of subtle effect.

Because no matter how long the human race endures, we will still have teenagers.

In the US, most people who smoke begin to do so at the age of 13 or thereabouts. As anyone who has spent time as an adult in a public school can tell you, the age of 13 is the nadir of human wisdom.