A Demographic Model of a World with Negligible Senescence

Few serious efforts have been made to generate robust demographic models of a near future in which radical life extension is achieved through rejuvenation therapies such as those of the SENS research programs. There is a paper from 2010 and little prior to that. Here a more recent model adds consideration of economic factors; the purpose isn't to predict what will happen, but to try to explore the likely nature of relationships between therapies to treat aging and extend healthy life spans, demography, and economic line items such as energy use and retirement.

Since the model used only explicitly factors in progress in technology via increased productive life span and GDP, I suspect the authors overstate concerns regarding energy and food. Even so, within their model the situation is hardly the Malthusian disaster predicated by people who subscribe to the overpopulation myth. The same model run in the 1930s, well before the green revolution in agricultural output, would probably have indicated far worse issues for food supplies, and also for the environment given the state of power generation technologies back then. Technology is not static, and efforts to improve it in specific ways are carried out in reaction to perceived shortcomings and expenses.

There is near certainty that the world will experience rapid population aging throughout this century, thanks primarily to widespread and substantial reductions in fertility and, secondarily, to ongoing extensions of life expectancy. Even as debate persists on biological limits to life, a growing body of demographic evidence suggests that improvements in human longevity are not diminishing, and may even be accelerating at older ages. At the same time, new breakthroughs in regenerative medicine and anti-aging therapies point to the possibility of improvements in longevity that are dramatic rather than incremental, and that reduce morbidity along with mortality. Yet, forecasts produced by governmental and intergovernmental organizations continue to assume a fairly narrow range of upside longevity variation, amounting to at most 10 years of added life expectancy. In this study, we take the opposite approach, exploring a future of very rapidly expanding life expectancy coupled with very low senescence. Using International Futures, a large-scale, long-term, integrated forecasting system, we explore the demographic, socioeconomic and ecological consequences of, and necessary adaptations to, such a world.

The purpose of this paper, then, is to consider the issues raised by a future of very rapidly expanding life expectancy coupled with very low senescence. More specifically, we want to look at how the world might evolve were there to be, over a 20-year period beginning as early as 2020, a rapid development and deployment of technologies that nearly eliminated mortality and morbidity from disease as well as eliminating infecundity. We label this world that of a Negligible Senescence scenario. We juxtapose this world with a Base Case scenario of more slowly progressing extension of life expectancy, accompanied by delayed but not ultimately reduced senescence (a more common forecast than that of negligible senescence). Our goal is not to model a likely future world, but rather to frame our understanding of the potential consequences of negligible senescence by evaluating the effects of a rapid and universal transition to such a regime.

We find that a world of negligible senescence would pose a number of immense challenges that go well beyond increased population size. The most obvious and immediate challenge lies with disseminating and paying for the life-saving intervention set itself. We estimate that rollout of such an intervention on a widespread basis would be infeasible even in the wealthiest countries if the initial price were set at $10,000 per year of healthy life added. At the price of $5000 per added healthy-life-year that we assumed through much of this paper, the initial financial burdens would be manageable for wealthy countries and would, over time, yield considerable reductions in disease-related expenditures that would more than offset the cost of the intervention. Yet poor and also middle-income countries would struggle to finance such an intervention even if, as we assumed, up to 95% of the costs in the poorest countries were defrayed through price reductions of the sort that have recently been observed for high-impact antiretroviral treatments.

With these caveats in mind, a world of negligible senescence would likely yield a still growing population of 14.8 billion by the year 2100, a considerable increase over the 7 billion today or the 10.1 billion forecast in our Base Case in 2100. Uncertainty in fertility, arising from the potential pronatalist impact of increased fecund spans and, on the other hand, the public interest in reducing fertility to check population growth, could yield a population with as many as 20 billion or as few as 11.6 billion.

A revolutionary jump in human longevity would require a comparable revolution in the meaning and timing of retirement. We explore scenarios that would see the average age of retirement rising to 114 by 2100 if fertility remained moderate. Even these relatively aggressive increases in retirement age necessitated a rise in savings from 22% today to 29% and doubling public pensions as a share of GDP, from 6% to something more like 14%. These increases would seem to be at the absolute edge of feasibility, and thus our retirement age scenarios should probably constitute something of a lower bound. On a positive note, individuals would still be able to enjoy decades of post-retirement life if they so chose, or embark on new patterns of employment, education, and leisure that are less defined by imminent mortality than the current pattern.

The potential addition of billions of people would concern many, especially given that this population (in the absence of negative feedbacks from environmental constraints) would see a GDP per capita 30% above the already substantial economic growth built into our Base Case. Energy demand levels, even with quite optimistic assumptions about efficiency gains and renewable contributions, would drive atmospheric CO2 levels above 600 ppm and, if coal were more heavily drawn upon without carbon sequestration, to 800 ppm or above. In the absence of food production technologies that are currently not on the forecast horizon, it might become nearly impossible to reduce the portion of the world's population that is undernourished.

Link: http://dx.doi.org/10.1016/j.techfore.2015.06.031


Yes, this is the paper I linked in the other thread, which I got from Aubrey de Grey's AMA. It's good that it's a very recent look into what could happen with negligible senescence. It's good that it gives insight to both potential positives and negatives. That being said, I don't think it's a stretch to think that critics who are against life extension will take this paper, highlight the potential negatives, and use it as reasons why this shouldn't be pursued. It highlights all the potential things (population, resources, retirement age) that critics already use. But it's understandable I suppose, as with anything else, all aspects should be covered and everything should be laid out on the table.

People now are freaking out about our current population, and things like wealth distribution. I could see this papers potential statistics being used against the life extension movement for sure. Aubrey said he thinks that everyone will have access to these treatments and that they'll basically pay for themselves, but even at the estimated $5000 per year of life for this treatment, the paper concedes that total distribution probably won't be likely for all countries, at least initially, and without large concessions. On the other hand, the paper also doesn't cover all the potential people who won't be interested in these therapies... Which judging by comments on aging articles seems to be a large amount. In real world practice, I suspect not nearly as many people will decline treatment... But only time will tell.

But Reason does make a good point that technology is not static, and will change over time... Hopefully fast enough to meet our projected needs. The paper doesn't really go into detail on other technologies such as automation that will come soon enough and how they will impact society either. I think technologically, we will be able to manage and control the process of aging, but only if society lets it happen. It does seem like there is going to need to be some massive social upheaval if this ever materializes, especially with things like retirement age and birth rates in various countries. But on the other hand, society is continually changing (albeit slowly) and none of this is going to happen overnight. There won't suddenly be a mass of 150 year olds appearing out of nowhere.

Posted by: Ham at August 7th, 2015 10:04 AM

It doesn't seem a much realistic paper. If negligible senescence is achieved, retirement age will be eliminated too. Also, treatment prices will not be constant. Maybe the first treatments will cost 5,000-10,000 $/year as they say, but it's very doubtful that these prices will not change from 2040 to 2100. They will probably be much much cheaper by 2050 or 2060.

And there is also the issue that Reanson mentions, with technology (for energy and food production) not being static.

Posted by: Antonio at August 7th, 2015 11:11 AM

I think perhaps a more salient issue is whether longevity therapy research should be publicly funded, the eventual therapy publicly available, and the formulations widely distributed below cost for people of less means (for whatever reason).
The simple answer is no and the complex answer is eventually - ideally in conjunction with cheaper means of producing and dispensing (administering) it.
Of course, it depends on what your priorities are: quickest means of getting a formulation out there? well then we need to move heaven and earth through government intervention, similar to a Manhattan Project or Apollo initiative - what are the collateral costs to every other program and initiative in the event of the cost/ brain/ facility drain? Monumental. Is it worth it to reduce pain and suffering? Only if you have already worked your way through the dozen or so other initiatives locally and worldwide that reduce pain and suffering to the number of people 'multiplied by' number of life years recovered (of course, this is most felt by developing nations and lifestyle-negligent individuals, i would hazard a guess). What of the increased productivity/production from increased healthy life - putting aside the notion that I believe (fundamentally) that people are not good, but not evil, necessarily - just lazy, greedy, and stupid (mostly defined as a level of selfishness that ranges from highly self-interested to toxic greed) that any increased years would be wasted and likely reduced due to later starting times, etc --- but, but beside that -> there are likely a dozen initiatives (woefully underfunded) which would address latent productivity, human potential, and society-contribution -- mostly in developing countries, mostly on decadent and wasteful tertiary education (50k tuition, anyone?), and of competitive and self-defeating economic systems. Perhaps this leaves us with government funded longevity as a human right - possibly, but compared to honourable but impractical initiatives elsewhere, longevity is very low down on the list of making the world a better place, such as: unlimited movement of immigrants, wealth redistribution to median income + 10%, removing all political boundaries and 'national' governments for a world government, and so on.. the bottom line is that despite the future potential (near unlimited) of longevity - a rush program, especially government supported (with all its inherent waste, risk aversion, and red tape) is a very low priority and would provide negligible benefits to a negligible number of people. Besides, 95%+ of all human beings have already died and there is every reason to believe that we have hundreds, if not thousands or millions of generations of humans going forward - why rush? why now? what does it matter if a solution comes in 20 years or 100? A billion people with an extra 20, 50 or 100 or more will always be a minuscule portion of the eventual future lives extended. That all being said, regular, intense, and sustained funding research and development should continue in the private sector with labs and willing personnel fully supported and engaged - as with expectations of every other research to stay relevant and sustaining. As a negative, false positives on unproven success or other bad publicity could turn public opinion further against it, even leading to levels of banning, similar to cloning, etc. As with climate change and other far future issues, there is obviously a benefit in continued work, but it is important to manage expectations and not let overblown sky-is-falling or conversely people-are-dying-unneccessarily alarmism. People and society are valuable but not infinitely so and pretending otherwise is to set up a conflict and drama spiral (see cloning, stem cells, etc) that could cause more obstacles than advances. Slow and steady and in the private sector with periodic reports of useful spin-offs (similar to the way space exploration is run) is the key.

Posted by: Jer at August 9th, 2015 8:57 AM

The benefits from a population that is locked into a perpetual youth model is that the resources spent raising and educating children today would all but disappear. Adult education would continue, but be at a much lower level resource wise than resources required today from toddler to post graduate. Any retirement would be economic rather than disability driven.

However, there are three interlinked critical resources that unless resolved - will limit any future of our species that resembles our current level of civilization. Like all species humans are food resource limited. Natural Human populations prior to the 1800s were limited primarily food production which was limited by the natural phosphorus cycle - the centuries it takes soils to regenerate bio-available phosphorus from rock phosphates.

The advent of petroleum energy linked increased production per unit effort with petroleum powered mechanization and the ability mine and process inorganic rock phosphate using cheap organic acids (from the petro-chemical industry) to produce bioavailable phosphate balanced fertilizers - NPK.

Under current technology petroleum energy is linked absolutely to food production NPK production - via the petro-chemical industry. The petro-chemical industry uses only 2% of the petroleum produced. However, the current food cost production paradigms are tied to current economy-of-scale of current petroleum industry. Shrink the petroleum industry in a significant way and you negatively impact the cost of NPK production and other agricultural management chemicals. These inter-connected economic dependencies are totally missed by this paper and most others trying to model the future.

Unless we are able to come up with a nearly "free" energy source to replace petroleum the human existence is surely coming to an impoverished and miserable end. Our hopes lie in fusion projects like the one being developed by Locheed Martin and others. Progress in developing in interrupting aging is likely to be lost in higher survival priorities unless far less energy can be developed that will lower the economic costs of producing agricultural bio-available fertilizers - like 95% of the planets food production is now dependent upon. Lack of viable food production/energy economics will therefore solve our excessive population problems one way or another - with0ut extreme technical innovation and then possibly a future better able to receive viable antiaging technologies.

Posted by: Durwood M. Dugger at August 9th, 2015 10:20 AM

You know, Jer, I was going to argue with that, but there's really not a lot to say; most of what's in that text splatter is so viscerally abhorrent (yes, let's let our countries be indefinitely invaded, our lives and our society aren't that important, so we won't bother trying to petition our governments to spend money on saving our own lives) that it rather speaks for itself.

Posted by: Slicer at August 9th, 2015 1:39 PM

It's 2015 and prophecies of doom and destruction are still doing a roaring trade. I think people just love disaster and horror stories deep down for some reason.

Personally I am not too worried about a larger global population, yes global warming seems to be happening, but society could very easily go to being carbon neutral using next gen nuclear that is melt down proof such as Nuscale's SMR or one of the molten salt reactors in development. The obstacles to either of these are really political.

Posted by: Jim at August 9th, 2015 4:29 PM

Jim: Indeed, current generation nuclear reactors are melt-proof. Fukushima's design was quite old (mainly a 1950's design and built in the last 1960's and first 1970's).

Posted by: Antonio at August 12th, 2015 5:43 AM

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