The problem with physical is often not enough space. The problem with digital is too much space. When new communication technologies expand the capacity to create more communication, people invariably create more communication. With the invention of the printing press, publishing exploded.

“In the year 1550 alone, for example, some 3 million books were produced in Western Europe, more than the total number of manuscripts produced during the fourteenth century as a whole,” Eltjo Buringh and Jan Luiten van Zanden wrote in their paper "Charting the 'Rise of the West.'"

In the last two years, we have created more data than in all previous history. We are now talking about zettabytes of data, a volume of data that is almost impossible to imagine. Let’s give it a try. Let’s try and imagine what a zettabyte would look like if it was printed out as books and how many trees that would require. To do that, let’s get a sense of what an average book might look like.

Richard Lea, writing for The Guardian in 2015, reported on a number of studies that indicated that fiction books had increased in length from around 300 pages in 1999 to around 400 pages in 2015. On the other hand, non-fiction books are getting shorter. “As recently as 2011, the average book length of the #1 non-fiction bestseller was 467 pages. By 2017, however, that number has dropped to 273 pages,” Tucker Max wrote for Scribe in 2017. Taking the fiction and non-fiction figures and averaging them gives us an overall average of 350 pages for a typical book.

“An average tree provides approximately 8,333 sheets of copy-type paper,” according to analysis by Conservatree. Thus, one tree can provide about 47 copies of a 350-page book. Decoline Shipping estimates that one tree would yield about 62 books. According to analysis based on research by TAPPI, a paper industry trade group, a typical tree will yield about 30 books.

Let’s say an average tree produces 50 350-page books and that on each of those pages there are between 250 and 300 words. That gives us about 100,000 words per book or five million words per tree. I tested how many KB were used for saving 100,000 words in a couple of formats and got an average of 500 KB. Let’s throw some images and tables into the mix and bring the size up to 1 MB, which would mean that an average tree stores about 50 MB of data.

A zettabyte is 1,000,000,000,000,000‬ MB or one quadrillion MB. If a zettabyte was printed out in 100,000-word books, with a few images thrown in, then we would have one quadrillion books. It would take 20,000,000,000,000 (twenty trillion) trees’ worth of paper to print these books. It is estimated that there are currently three trillion trees on the planet. To print a zettabyte of data would thus require almost seven times the number of trees that currently exist to be cut down and turned into paper.

It is estimated that by 2035 there will be 2,000 zettabytes of data in the world.