Going Green May Save Us from an Alien Invasion

One day, artificial photosynthesis could provide ultra efficient conversion of the sun’s energy into electricity while simultaneously scrubbing carbon dioxide and perhaps other greenhouse gases from the atmosphere. The idea of green—perhaps literally—solar energy collectors on the tops of buildings and cars reminded me of Karl Schroeder’s notes on the invisibility of advanced civilizations. His basic idea is that an advanced society will integrate itself into its environment rather than construct huge technological marvels that stick out like a sore thumb. While it’s difficult to envision how we might offload literal computation—like balancing the checkbook or playing World of Warcraft—into the environment, it certainly appears that artificial photosynthesis and other radical green technologies are the first steps down that road.

A transformation into a zero-footprint society has implications beyond sustainability. Schroeder’s notes are an answer to the Fermi paradox, which asks, “If extraterrestrial intelligence is common, where is everyone?” The answer in this case is that we can’t detect them because they’re essentially invisible thanks to their integration into their environment. As we integrate ourselves into our environment, we too become invisible to outsiders. This is non-trivial.

There is an active and not always amicable debate in SETI circles over whether we should limit ourselves in merely listening for signals from extraterrestrial intelligences (known as “passive SETI”) or attempt to contact them ourselves (referred to as “active SETI”) (additional coverage by David Brin and Daily Galaxy). The contention is the non-zero possibility that active SETI might alert a malevolent entity to our presence, thereby dooming humanity. But if we manage to make ourselves invisible between now and when our signal reaches our would-be foe, they may decide that there’s nothing interesting on our little blue speck after all. Thus, our quest for sustainable technologies might, one day, save us from an alien invasion.