This is a linkpost for https://www.nytimes.com/2021/04/27/magazine/global-life-span.html (if you cannot access the article due to a paywall, consider getting the pocket browser extension, and then save the article to pocket)

This New York Times article from 27 April 2021 provides an interesting overview of some of the most important contributors to increases in human lifespans over recent centuries: variolation, water chlorination, pasteurisation, evidence-based medicine, antibiotics, vaccinations, smallpox eradication, oral rehydration therapy, and others.

Importantly, the article emphasises not only the key role that the scientific discoveries of the above methods played but also the important role of activists, policymakers, and institutions like the CDC and WHO in promoting and implementing these methods. 

One strange thing about the story of global life expectancy is how steady the number was for almost the entirety of human history. Until the middle of the 18th century, the figure appears to have rarely exceeded a ceiling of about 35 years, rising or falling with a good harvest or a disease outbreak but never showing long-term signs of improvement. A key factor keeping average life expectancy low was the shockingly high rates of infant and childhood mortality: Two in five children perished before reaching adulthood. Human beings had spent 10,000 years inventing agriculture, gunpowder, double-entry accounting, perspective in painting — but these undeniable advances in collective human knowledge failed to move the needle in one critical category: how long the average person could expect to live.

The period from 1916 to 1920 marked the last point in which a major reversal in global life expectancy would be recorded. (During World War II, life expectancy did briefly decline, but with nowhere near the severity of the collapse during the Great Influenza.) (...) And while Western nations surged far ahead in average life span during the first half of the last century, other nations have caught up in recent decades, with China and India having recorded what almost certainly rank as the fastest gains of any society in history. A hundred years ago, an impoverished resident of Bombay or Delhi would beat the odds simply by surviving into his or her late 20s. Today average life expectancy in India is roughly 70 years.

In effect, during the century since the end of the Great Influenza outbreak, the average human life span has doubled. There are few measures of human progress more astonishing than this. If you were to publish a newspaper that came out just once a century, the banner headline surely would — or should — be the declaration of this incredible feat. But of course, the story of our extra life span almost never appears on the front page of our actual daily newspapers, because the drama and heroism that have given us those additional years are far more evident in hindsight than they are in the moment. That is, the story of our extra life is a story of progress in its usual form: brilliant ideas and collaborations unfolding far from the spotlight of public attention, setting in motion incremental improvements that take decades to display their true magnitude.

The curious, almost counterintuitive thing about the first stage of the great escape is that it was not meaningfully propelled by medical drugs. Vaccines could protect you from future infections, but if you actually got sick — or developed an infection from a cut or surgical procedure — there was very little that medical science could do for you. There was no shortage of pills and potions to take, of course. It’s just that a vast majority were ineffective at best. The historian John Barry notes that “the 1889 edition of the Merck Manual of Medical Information recommended one hundred treatments for bronchitis, each one with its fervent believers, yet the current editor of the manual recognizes that ‘none of them worked.’”

Mary Hunt, (...) was a bacteriologist from the Peoria lab, assigned the task of locating promising molds that might replace the existing strains that were being used. (Her unusual shopping habits ultimately gave her the nickname Moldy Mary.) One of Hunt’s molds — growing in a particularly unappetizing cantaloupe — turned out to be far more productive than the original strains that Florey and Chain’s team had tested. Nearly every strain of penicillin in use today descends from the colony Hunt found in that cantaloupe.

A crisis like the global pandemic of 2020-21 gives us a new perspective on all that progress. Pandemics have an interesting tendency to make that invisible shield suddenly, briefly visible. For once, we’re reminded of how dependent everyday life is on medical science, hospitals, public-health authorities, drug supply chains and more. And an event like the Covid-19 crisis does something else as well: It helps us perceive the holes in that shield, the vulnerabilities, the places where we need new scientific breakthroughs, new systems, new ways of protecting ourselves from emergent threats.

All those brilliant solutions we engineered to reduce or eliminate threats like smallpox created a new, higher-level threat: ourselves. (...) We know from our recent history during the industrial age that scientific and technological progress alone do not guarantee positive trends in human health. Perhaps our increasingly interconnected world — and dependence on industrial livestock, particularly chickens — may lead us into what some have called an age of pandemics, in which Covid-19 is only a preview of even more deadly avian-flu outbreaks. Perhaps some rogue technology — nuclear weapons, bioterror attacks — will kill enough people to reverse the great escape.