An elderly man swimsAl Bello/Getty Images

One of the great stories of the 20th Century was the dramatic extension of the human lifespan.

Advances in medical technology, disease eradication, and improved living conditions made it far more common and normal for people to live into old age. In 1900, global life expectancy was 31. In 1950 it was 48. In 2010 it was 70.

So the question is: What’s next?

Some people claim that the trend will continue apace, and that people will soon live to be 150, 200, even 1,000. More sober analysis suggests there’s an upper limit to the human lifespan, and we’re getting close.

The challenge, then, is to help more people reach the full extent of their lives, and do so more healthily and more comfortable in their own bodies and minds than medical science currently allows. Already, there are projects on the table that show tremendous promise — and others that are unlikely but fascinating to think about.

Welcome to the next 10 years of human longevity.