Gwynne Dyer: Average lifespan is still increasing

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      Everybody knows where the population explosion came from. Two centuries ago birth rates and death rates were high everywhere, and population growth was very slow. Then clean water, good food and antibiotics radically cut the death rateand the human population of this planet increased 300 percent in the past 90 years.

      Eventually, as people moved into the cities and big families were no longer an advantage, the birth rate dropped too. The world’s population is still growing, but it will only increase by 50 percent in the next 90 years. So far, so obvious. But what’s happening to the human lifespan is equally dramatic.

      Here’s the key statistic: the average human lifespan in a developed country has been increasing at three months per year ever since the year 1840.

      Everybody assumes that lifespan grew much faster in the 19th and early 20th centuries, and is growing much slower now. But no. It has plodded along at the same rate, adding about three months to people’s life spans every year, for the past 175 years. And yes, that does mean that a baby born four years from now can expect to live, on average, a whole year longer than a baby born this year.

      There have always been some people who lived to 70 or 80, but the average age at death in 1840 was only 40 years. By the year 2000 it was 80 years. That’s 40 more years of life per person in 160 years.

      And lifespan is still increasing at the same rate. In Britain, for example, the average lifespan has increased by 11 more years in the past 44 years. Three months per year, just like in the 19th century.

      This is why actuaries predict that babies born in the year 2000 will have an average lifespan of 100 years. Give those babies the 80 years of life that people who died in 2000 enjoyed, then give them an extra three months for every one of those 80 yearsand they will have 20 years more years to live. That is, an average of 100 years.

      This sounds so outlandish that you instinctively feel there must be something wrong with it, and maybe there is. The fact that it has gone on like this for 175 years doesn’t necessarily mean that it will go on forever. But it’s not stopping or even slowing, so the smart money says that it will continue for quite a while yet

      What about the developing world? Most of it has been playing catch-up, and by now the gap isn’t very big any more. In China the average lifespan was only 42 years as recently as 1950but then it began increasing by six months per year, so that the average Chinese citizen can now expect to live to 75. Once you hit an average lifespan of 75 years, however, the pace slows down to three months per year, the same as in the developed countries.

      India is a little behind China: average lifespan was still 42 years in 1960, and is now 68, so it’s still going up at six months per year. But we may expect to see it fall to the normal three months per years in about 2030, after the average Indian lifespan reaches 75.

      All the developing countries of Asia, Latin America and the Middle East are in the same zone. The sole exception is Africa: where 35 countries have average life spans of 63 years or lower. But even most African countries are seeing a slow growth in average lifespan.

      So do we end up with a huge population of people so old they can barely hold their heads up, let alone eat solid food? Probably not.

      Three hundred years ago Jonathan Swift wrote about people like that in his satire Gulliver’s Travels. Struldbrugs, he called them: people who could not die, but went on ageing until they were so decrepit and disabled that death would have been a mercy.

      They were declared legally dead when they reached eighty, as otherwise their longevity would mean they ended up owning everything. But they weren’t really dead; now it was the public that had to support them for the rest of their interminable lives.

      In real life, crippling diseases and disabilities are still mainly a phenomenon of the last decade of life, and as the lifespan lengthens that final decade also moves.

      Demographers now talk about the “young old”, who are in their 70s and 80s and still in reasonably good shapeand the “old old”, in their 90s and 100s, who are mostly frail and in need of care. So the time is probably coming when people must work until into their 80s, because the over-65s will amount to a third of the population. No society can afford to support so many.

      But by then people won't be decrepit in their 80s. And the only alternative is dying younger.

      Gwynne Dyer is an independent journalist whose articles are published in 45 countries.

      Comments

      7 Comments

      I Chandler

      Jan 15, 2015 at 12:12pm

      Dyer:"Then clean water, good food and antibiotics radically cut the death rate"

      I was expecting a plug for GMOs...It's not so much what Dyer writes as what he does not write...
      Last week it was the missing 1999 Mosow apartment bombings from his terror history list.
      And no - The 50 cent party aren't paid in rubles, they're paid by the word - in Yuan:
      https://firstlook.org/theintercept/2014/02/24/jtrig-manipulation/

      I was also expecting a mention of Cuba where "a province records the World's lowest infant mortality rate. Over 2,000 health specialists from the province (Cienfuegos) collaborate in international missions in 35 countries of the world, including many stationed in West Africa to fight against the spread of the Ebola virus. Cuban health professionals abroad provide medical training, contribute to clinical tests, like the vaccines against cholera and pneumococcal disease."

      Dyer: "India is a little behind China: average lifespan was still 42 years in 1960, and is now 68"
      India needs to clean up:
      http://ericmargolis.com/2014/12/indias-public-health-disaster/

      I Chandler

      Jan 15, 2015 at 1:17pm

      Dyer: "India is a little behind China: average lifespan was still 42 years in 1960"
      !960? 1947 would be more interesting. Lifespan in India was ~38 years in 1950:

      http://www.china-profile.com/data/fig_WPP2008_L0_1.htm - It seems colonialism was not good for either country a picture is descriptive.

      Dyer: "The sole exception is Africa: where 35 countries have life spans of 63 years or lower."
      I'm sure modernization—democracy, equality, the whole cultural package will help these countries...

      Lewis S

      Jan 15, 2015 at 6:23pm

      Should Dyer also consider GMOs, - as mentioned above -, for increased food production, and consider the use of fossil fuels - as the CO2 in the atmosphere indicates - for the benefits of controlling temperature in our homes and work places reducing the number of deaths caused by freezing and heat stroke for there contribution to the increase in life expectancy?

      While a correlation exists between life expectancy and the CO2 content in the atmosphere, CO2 does not directly lead to increased life expectancy only that the use of fossil fuels have improved living conditions which has contributed to longer life expectancy.

      doconnor

      Jan 16, 2015 at 10:41am

      "for the benefits of controlling temperature in our homes and work places reducing the number of deaths caused by freezing and heat stroke for there contribution to the increase in life expectancy?"

      I've read a couple of places that controlling your temperature too much reduces your the energy you spend warming or cooling yourself which increases obesity and could contribute to decreased life expectancy.

      McRetso

      Jan 16, 2015 at 12:42pm

      @Chandler

      Are you really treating it as suspicious that the author of an 800 word article failed to mention a few key historical points? Do you not understand how column writing works?

      But then, this is coming from a guy who thinks Libya is in Sub-Saharan Africa and that Predator drones are piloted by artificial intelligence, so I suppose I should be impressed that Chandler managed to turn his computer on and type.