If you look at our planet from space, what you see is something like a neural network with the cities as its nodes, and that is as good an image of the planet as a complex system of systems as one could hope for.
With the emergence of the internet in the mid-90's, the world became one global commons. In the past, we could understand that there was some mysterious unity to the various dimensions of life but we couldn't understand its dynamics, we couldn't observe and measure their interactions. We basically operated like the drunk who looks under the streetlight for his keys because that's where he can see.
Video featuring, from IBM: Mike Wing, Irving Wladawsky-Berger and Julia Grace.