How the World Really Works: A Scientist’s Guide to Our Past, Present and Future

by Vaclav Smil

Beyond that, we get into realms where it is easy to make order of magnitude mistakes: some rich families (business founders, owners, or lucky inheritors) now add annually to their holdings tens (107) or hundreds (108) of millions of dollars; in 2020 the world had about 2,100 billionaires (109 dollars), and the richest ones are now valued at more than $100 billion or 1011 dollars.2 In terms of individual net worth, compared with the few dollars’ worth of tattered clothes and the worn-out shoes of a destitute African migrant, the gap is thus 10 orders of magnitude. This difference is so large that we can find no equivalent among the properties separating the two most notable classes of terrestrial animals: birds and mammals. The difference between the body masses of the smallest and the largest mammals (the Etruscan shrew at 100 grams and the African elephant at 106 grams) is “just” six orders of magnitude. The difference between the wingspan of the smallest and the largest flying birds (the bee hummingbird at 3 centimeters and the Andean condor at 320 centimeters) is only two orders of magnitude.3 Clearly, some humans have gone far further than natural evolution ever could in separating themselves from the crowd.