According to Kaku, we are now in what he calls a Type 0 civilization. A type 1 civilization will be able to capture the free energy of an entire planet, and will have mastered the interplanetary environment. A type 2 civilization will be able to gather the free energy of entire solar systems, allowing the colonization of nearby star systems. And finally, a type 3 civilization will be capable of roaming entire galaxies. A type 1 civilization would be able to survive calamities natural or man-made limited to the Earth itself, but would still be vulnerable to nearby supernovae and gamma ray bursts, the impending collision with the Andromeda galaxy in 4 billion years, and the death of the Sun itself. Type 2 civilizations would have more survivability, and a type 3 civilization would be for practical purposes immortal—until, that is, the entire universe runs out of free energy.
Granted, we humans have our dark side, and we may cause our own extinction. On the bright side, it should be noted that human evolution seems to be accelerating. After 100,000 years of stone-age technology, it took only 10,000 years to reach the industrial revolution that began 200 years ago. Therefore, we can predict that humans will reach full type 1 status within the next 800 years or less. Indeed, considering that humans already co-opt 40% of Earth’s net primary productivity, that we have sent men to the Moon and probes to every planet except Pluto, and that we could—if we had the political will—manage the Earth’s atmosphere to maintain any desirable, global, average temperature, it would seem that we are already half-way to type 1 status. Michio Kaku himself has suggested that we will achieve type 1 status within a century—as long as we can stave off the terrorists who would have us return to a type -1 civilization.
