If you take as a given that humans now live on a geoengineered planet, then what is our responsibility for the future? Before discussing how to deal with Earth systems, Brad Allenby asks that we think carefully about the complexity of human systems, especially our tendency to generate far more complexity than we realize, and to assume “that we have a reasonable handle going forward…and can therefore talk about (the future) with some degree of rationality.”

In a talk that kicks off with quotes from Stewart Brand, William Gibson and Vishnu, Allenby pulls together some trends “we should care about” when discussing solutions for global issues. He notes that just as railroads changed American culture and self-perception in unexpected ways, so will the integrated impact of technology. Nanotechnology, robotics, biotechnology, information and communication technology are all changing at the same time, “so the idea that we can make projections out 100 years is laughable.” Allenby also notes that, to our peril, we’re integrating natural systems into human systems, handing off what had been public concerns to commercial interests, failing to develop a governing ethical structure for “complex adaptive systems,” all at a time when the end of the Cold War has destabilized global power relationships.

Allenby worries that we are dabbling in systems management well over our heads, building information structures into our cities’ infrastructure, for instance, and utilizing humans as “design spaces.” Don’t forget how the global stock market crashed, in spite of carefully designed computer trading systems, he reminds us. How can we approach earth systems engineering in a way so as to do no harm, much less leave things better off? Some principles Allenby recommends: “Only intervene when necessary and to the extent required;” model complicated systems before implementing them, and whenever possible, make incremental and reversible change; acknowledge the social engineering agendas that underlie the climate debate, and the interplay between scientific analysis and values; and bring all parties to the discussion, “not just engineers sitting with scientists, but with post-modern English critics.”