III. Ecosmos: A 21st Century Fertile, Habitable, Solar-Bioplanet Lifescape
3. Earth Alive: A GaiaSphere Sustains Her/His Own Viability
Earth’s biosphere is now known to have regulated itself for some billion years in a homeostatic fashion so as to sustain conducive atmospheric and geochemical conditions for life’s survival and evolution. Since the 1970's, the British geochemist James Lovelock, with Lynn Margulis and colleagues, have provided theoretical and experimental support for living systems as a planetary phenomenon. Lovelock's country neighbor, the author William Golding, suggested the name of the earth goddess Gaia. The concept has received intense scrutiny, often rejection, over past decades but has become understood and accepted as an innovative, useful model.
Meyers, Stephen and Alberto Malinverno. Proterozoic Milankovitch Cycles and the History of the Solar System. Proceedings of the National Academy of Sciences. 115/6363, 2018. University of Wisconsin and Columbia University geoscientists expand Earth’s environs to include a dynamic spacescape and temporal depth to its earliest origin. See also Exo-Milankovitch Cycles II: Climates of G-dwarf Planets at arXiv:1805.00283.
Periodic variations in Earth’s orbit and rotation axis occur over tens of thousands of years, producing rhythmic climate changes known as Milankovitch cycles. The geologic record of these climate cycles is a powerful tool for reconstructing geologic time, for understanding ancient climate change, and for evaluating the history of our solar system, but their reliability dramatically decreases beyond 50 Ma. Here, we extend the analysis of Milankovitch cycles into the deepest stretches of Earth history, billions of years ago, while also reconstructing the history of solar system characteristics, including the distance between the Earth and Moon. Our results improve the temporal resolution of ancient Earth processes and enhance our knowledge of the solar system in deep time. (Significance)
Alvarez, Walter. A Most Improbable Journey: A Big History of Our Planet and Ourselves. New York: Norton, 2016. In a novel volume, the eminent UC Berkeley geologist joins this popular union of human temporal appearance with a cosmic evolutionary rooting. We log in at the same time as David Christian’s Big History and David Grinspoon’s The Earth in Human Hands. But the three otherwise fine works reflect a tacit mindset, or lack thereof, that this grand cosmos to culture vista yet results from random contingency or chance, a lottery without occasion or destiny, not to occur elsewhere or again.
One in a million doesn’t even come close. Not when we’re talking about the odds that you would happen to be alive today, on this particular planet, hurtling through space. Almost fourteen billion years of cosmic history, over four billion years of Earth history, a couple million years of human history, the rise and fall of nations, the unbroken string of generations necessary to lead to you―it’s staggering to consider. Yet behind everything in our world, from the phone in your pocket to even the force of gravity itself, lies a similarly grand procession of highly improbable events. This panoramic viewpoint has captured the imagination of historians and scientists alike, and together they’ve created a new field―Big History―that integrates traditional historical scholarship with scientific insights to study the full sweep of our universe and its past. Famed geologist Walter Alvarez―best known for the impact theory explaining dinosaur extinction―has championed a science-first approach to Big History, and A Most Improbable Journey is one of the first Big History books to be written by a scientist rather than a historian. (Publisher)
Arenes, Alexandra, et al. Giving Depth to the Surface: An Exercise in the Gaia-Graphy of Critical Zones. Anthropocene Review. Online June, 2018. We note this entry by a landscape planner A. Arenes, the sociologist of science Bruno Latour and geochemist Jerome Gaillardet, as a visual exercise to take in the whole bio-regulated Earth as some manner of solar heated, life bearing, people evolving, preciously fertile abode.
Foregrounding the importance of soil and more generally the surface of the Earth – what is now often called the critical zone (CZ) – remains very difficult as long as the usual planetary view, familiar since the scientific revolution, is maintained. In this joint effort coauthored by a landscape architect, a historian of science and a geochemist, we propose what is called in history of drawing an anamorphosis, a change in perspective that allows us to shift from sites located in the geographic grid, to a representation of events located in what we call a Gaia-graphic view. We claim that such a view is much better suited to situate the new actors of the Anthropocene because it brings pride of place to the CZ. (Abstract edits)
Arney, Giada, et al. The Pale Orange Dot: The Spectrum and Habitability of Hazy Archean Earth. Astrobiology. 16/11, 2016. In the thrall of our global collaboration, an astroscientist team from the USA, UK, and France cast back some 2.6 billion years to reconstruct ancient climates, photochemistry, and especially fractal atmospheric hazes and clouds. Whom then is this personsphere progeny arising out of the mists to be able to learn this? As if a late blossom or birth, what does it say about what manner of organic object an Earth might be?
Arthur, Rudy and Arwen Nicholson. Selection Principles for Gaia. Journal of Theoretical Biology. October, 2021. University of Exeter bioecologists and colleagues of Tim Lenton there offer a further finesse of propensities and activities by which to explain and qualify this especial, lively abode upon which a sentient speciesphere might finally be able to figure all this out.
The Gaia hypothesis considers the life-environment coupled system as a single entity that acts to regulate and maintain habitable conditions on Earth. In this paper we discuss three mechanisms which could potentially lead to a vital Gaia: Selection by Survival, Sequential Selection and Entropic Hierarchy. We use the Tangled Nature Model (H. Jensen) of co-evolution as a common framework for all three. This idea which combines sequential selection with a reservoir of diversity tends toward growth and increases resilience of the Gaian system over time. This paper adds a further taxonomy of “Entropic Gaia” whence biomass, complexity and enhanced habitability over time are likely features of a co-evolving Earth, and exoplanetary, system. (Abstract excerpt)
Benner, Steven, et al. Planetary Biology. Science. 296/864, 2002. As “a civilization-wide enterprise,” the global expanse of life and its human phase is reconstructed akin to a developing, cognizant organism.
Consequently, one can imagine a comprehensive model of life on Earth combining paleontology, geology, structural biology, systems biology, and genomics, that captures history and function from molecule to the planet. (867)
Bertrand, Philippe and Louis Legendre. Earth, Our Living Planet: The Earth System and its Co-evolution with Organisms. International: Springer Frontiers, 2021. Veteran French and French-Canadian physical geochemists provide a latest, thorough explanation how our home bioworld is distinguished by a unique propensity to form and maintain itself in a viable fashion, as if alive. Topical chapters include The Atmosphere, Overall Habitability, Natural Greenhouse Effect, Earth’s Magnetic Field, Feedback Cycles and much more.
This book investigates the billion-year takeover of planet Earth by its organisms and ecosystems by way of vital interactions between environmental and biological mechanisms. Key relationships are identified among nested phases from ecosystems to the Earth System, the Solar System, and the Universe. This chapter considers successively five aspects of the Earth System in the context of the Solar System: the organisms, which are subject to biological evolution, and their key features; the Solar System, populated by billions of objects, which is the homeland of Earth in the Universe; Earth together with its sister planets and their moons; a brief history of the 13.7 billion-year Universe; and a brief history of 4.6 billion-year Earth. (Chapter 1 Abstract excerpt)
Braakman, Rogier, et al. Metabolic Evolution and the Self-Organization of Ecosystems. Proceedings of the National Academy of Sciences. Online March 27, 2017. An MIT environmentalist, Earth scientist, and a biologist construct an extensive synthesis of diverse organisms and their bioregions as they proceed to dynamically organize and prosper. Life’s long development takes on an anatomic and physiological guise as these innate, formative forces gain theoretical credence.
Understanding what drives self-organization in complex systems and how it arises is a major challenge. We addressed this challenge using dominant oceanic photosynthetic and heterotrophic microbes as a model system. Reconstructing the metabolic evolution of this system suggests that its self-organization and self-amplification were coupled and driven by an increasing cellular energy flux. Specifically, the evolution of cells steadily increased their metabolic rate and excretion of organic carbon. We describe how this increases cellular nutrient uptake and thereby ecosystem biomass. The release of organic carbon, in turn, promotes positive feedbacks among species that reinforce this evolutionary drive at the ecosystem level. We propose the evolutionary self-organization of oceanic microbial ecosystems contributed to the oxygenation of Earth. (Significance)
Bunyard, Peter, ed. Gaia in Action: Science of the Living Earth. Edinburgh: Floris Books, 1996. Scientific and philosophical papers explore this holistic, ecological hypothesis. The authors look toward the Russian geoscientist Vladimir Vernadsky as its original founder earlier in the 20th century whose theories of the inherent emergence of living matter informs the volume.
Chao, Keng-Hsien, et al. Lava Worlds: From Early Earth to Exoplanets. arXiv:2012.07337. In our late day of global collaborations and knowledge accumulation, by way of 400 references, University of Hawaii astronomers including Eric Gaidos can proceed to reconstruct and quantify how our fittest biosphere came to have its certain hyperactive crustal substance. The retrospective endeavor considers thermal energies, atmospheric material transport, tidal forces, gravity effects and more to attain both a conceptual version for Earth, and a model which can then be applied to vicarious exoworlds.
The magma ocean concept was conceived to explain the geology of the Moon, global oceans of silicate melt could be a "lava world" phase of rocky planet accretion, and persist on planets around other stars. Magma oceans could be a defining stage in forming a core, a crust, initiation of tectonics, and of an atmosphere. This review describes the energetic basis of magma oceans and lava lakes on Earth and Io and their evidence throughout the Solar System. It describes research on theoretical and observed exoplanets that could host extant lava worlds and ways to detect and characterize them. (Abstract excerpt)
Crist, Eileen and H. Bruce Rinker, eds. Gaia in Turmoil: Climate Change, Biodepletion, and Earth Ethics in an Age of Crisis. Cambridge: MIT Press, 2010. This hypothesis is not in peril, rather it is the biosphere due to an unchecked onslaught from a consumptive civilization. The usual proponents from James Lovelock himself, still fiesty at ninety, Lynn Margulis, Tyler Volk, Stephan Harding, Timothy Lenton, Connie Barlow, and an array of ecologists and philosophers who weigh in with the latest impressions. The editors introduction is “One Grand Organic Whole.” A salient contribution is “Principles of Gaia Governance” by University of Washington political scientist Karen Litfin.
Dauphas, Nicolas. The Isotropic Nature of the Earth’s Accreting Material through Time. Nature. 541/521, 2017. The University of Chicago geophysicist reports new findings about how our home bioplanet formed by gradual additions of moon, and meteorite size masses, which were similar in chemical composition. This work, along with a companion article Ruthenium Isotopic Evidence for an Inner Solar System Origin of the Late Veneer (mantle) in the same issue, merited notice as Earth’s Building Blocks (541/468).