Steven Johnson: How We Doubled Life Expectancy in the 20th Century

The Extra Life author on past scientific breakthroughs, COVID-19 vaccines, and renewing trust and confidence in public health agencies.


"It took us four years just to identify the virus that caused AIDS in the '80s," says Steven Johnson. "Imagine COVID where it's four years before we even know what is causing the outbreak. That's what would have happened if we just shifted 20 years, 30 years earlier in terms of when this outbreak happened."

Johnson is the author of the new book Extra Life: A Short History of Living Longer, which is also running as a series on PBS (watch online here). The rapid advance in vaccine technology, which is bringing an end to the COVID-19 pandemic, is best understood in the context of a series of innovations that more than doubled the life expectancy of the human race over the last 100 years. Extra Life explores how innovations in epidemiological statistics, artificial fertilizer, toilets, and sanitation systems, along with vaccines and other measures, have allowed billions of people to flourish until old age. By 2016, global life expectancy at birth had reached 72 years, according to the World Health Organization. 

Johnson was a founder of the pioneering website Feed in the 1990s and has authored a shelf full of books about human progress, including such bestsellers as The Ghost Map, which recounted how doctors and researchers ended the threat of cholera in 19th-century London, and Future Perfect, which argued that the modern networked world is far more resilient than previous iterations.

He talks with Nick Gillespie about how we managed to massively increase our lifespans in the 20th century, and whether we can do even better in the 21st. They also talk about performance of the World Health Organization, the Centers for Disease Control and Prevention, and the Food and Drug Administration when it comes to COVID-19 and how those agencies might rebuild trust and confidence in the post-pandemic world.