Abstract. All populations, including humans, are sustained by fluxes of energy and materials from a finite environment. Physical constraints on biological design result in ubiquitous and predictable allometric scaling laws, pervasive in ecological theory. However, unique to the human species is its capacity to harness extra-metabolicenergy in the form of renewables and fossil fuels to power the development of more complex societies, from agricultural and industrial to modern technological lifestyles. We use ecological theory to compare variation in densities and individual energy use in human societies (varying in societal complexity) to other land mammals. We show that societal complexity (from hunter-gatherers to modern cities) not only associates with greater energy fluxes (both per capita and at a population scale), but also allows escaping from ecological laws. Moreover, densest cities across the globe flux greater energy than net primary productivity on a per area basis, becoming sinks. This condition poses formidable challenges for establishing a sustainable relationship on a finite planet.
To evaluate sustainable conditions for the demands of these hyper-dense modern societies, we develop a mathematical model of socio-ecosystems that couples human population growth, technological development, and the benefits humans obtain from ecosystem services. We focus our analyses on the role of green technologies that increase the provision of ecosystem services with few negative externalities or environmental costs. We find that without any green technologies, hyper-dense societies provide less than a basic standard of living conditions. However, when parameters cause socio-ecosystems to create green technologies, basic standards of human well¬being are guaranteed but limited. Such limitations are exceeded when there is positive feedback in green technological development. In this case, socio-ecosystems go beyond limited material wellbeing and into a “star trek” regime where material wellbeing is effectively unlimited. Other regimes in the model describe limits to human population size including population collapse. Overall, our results quantify the speed the modern societies need to shift to green technology in order to achieve desirable outcomes and avoid impending catastrophes.
(Work done by Burger JR, Quiñinao C, Marquet PA, Weinberger VP, in alphabetic order)
This talk will stream live from SFIs YouTube channel.