The role of closed ecological systems in carbon cycle modelling

Abstract

Acquiring a mechanistic understanding of the role of biotic feedbacks for the links between atmospheric CO 2 concentrations and temperature is essential for trustworthy climate predictions. Currently, computer-based simulations are the only available tool to estimate the global impact of biotic feedbacks on future atmospheric CO 2 and temperatures. Here we propose an alternative and complementary approach by using materially closed, energetically open analogue/physical models of the carbon cycle. We argue that there is unexplored potential in using a materially closed approach to improve our understanding of the magnitude and direction of many biotic carbon feedbacks and that recent technological advances make this feasible. We also suggest how such systems could be designed and discuss the advantages and limitations of establishing physical models of the global carbon cycle. BackgroundAs a species we are effectively "trapped" on a planet which, for all practical purposes, is materially closed, but energetically open (Fuller and Snyder 1969). With the exception of the cosmic debris that falls into the atmosphere and the negligible quantities of matter in satellites and the light gases that escape into outer space, the Earth is materially closed (Morowitz et al. 2005). We have no real choice other than to survive within this closed system and, more critically, to ensure that it remains sustainable. From cells to ecosystems and through to biomes, there is no other biological or ecological scale besides the Biosphere (Vernadsky 1926) at which life is able to persist in the absence of significant matter Climatic Change (2012) 112:709-716

Spatial structure affects the establishment and persistence of closed microbial ecosystems

“…Short of being able to replicate the planet itself, closed ecosystems approaches are wellsuited to explore questions of biological persistence and matter recycling (Taub, 1974;Kearns and Folsome, 1981;Obenhuber and Folsome, 1988;Rillig and Antonovics, 2019), and have been proposed as a means to investigate global carbon cycling (Milcu et al, 2012). Modeling closed systems has furthered our understanding of self-sustaining systems, including thermodynamic restraints on matter recycling (Goyal et al, 2023).…”

On Gaia: a critical investigation of the relationship between life and Earth

“…As Free and Barton [10] pointed out, however, because for most of the history of life on Earth all life was microbial it would be reasonable to use simple microbial microcosms to make a start, at least, with experimental Gaian research. The work of Alaxandru Milcu, Phil Ineson and colleagues on small carbon cycle microcosms provide examples of possible approaches and also illustrate the challenges of such an approach [29,30]. There may be questions about the universal generality of such experiments as they can only use organisms from a Gaian planet with a history of over three billion years of continuous life.…”