How a videogame taught my generation that Earth is alive

Like many environmental scientists, early exposure to nature sparked my interest in the field. But so did the 1990 video game SimEarth, game studio Maxis's first release after SimCity. SimEarth was more than mere entertainment, however. It was Maxis co-founder Will Wright’s effort to disseminate an idea that captivated him: The Gaia Hypothesis, which proposed that Earth is alive.

Developed by NASA astrobiologist James Lovelock and microbiologist Lynn Margulis, a pioneering researcher on the origins of life, the Gaia Hypothesis sounds more like New Age spirituality than science. But in the 1980s and early 1990s, many stolid Earth scientists took it seriously. NASA credits Gaia theory with helping spur the development of Earth system science, the field that explores how our planet's atmosphere, oceans, ice, rocks, and ecosystems interact and shape each other. Wright, who saw himself as something of a science popularizer in the mold of Carl Sagan, wanted everyone to know about it.

"SimEarth gives you the chance to enter the Gaia argument as a player," Lovelock wrote in an introductory essay for the SimEarth Bible, a 224-page aftermarket strategy guide published in 1991, a year after the game's release. Lovelock, who consulted with Wright during SimEarth's development and whose "Daisyworld" model appears as an in-game tutorial, considered SimEarth a sophisticated representation of the planet on par with global climate models.

Of course, as a seven-year-old booting up SimEarth on my family's Performa Macintosh computer, I didn't know any of this. I just saw a pixelated garden of possibilities.