Earth system science
Earth system science concerns the application of systems science to the Earth as a whole. It considers interactions between the planet's primary spheres - biosphere, atmosphere, hydrosphere and geosphere. Growing from systems theory, systems science often concerns self-regulating systems in particular, i.e. systems that can self-correct through feedback mechanisms, and so Earth system science applies such feedback mechanisms to these largest spheres of the planet and to the subsystems through which they operate. The first application of cybernetic feedbacks to the Earth as a whole was by James Lovelock, in what he was initially going to call the 'Earth Feedback hypothesis', but which he later named the Gaia hypothesis (today often called Gaia theory).
As it is a prime example of an emergent property of the planetary system which cannot be understood without regarding Earth as a single integrated entity, a common focus in Earth system science is the Earth’s climate. As one example of this, leading American climatologist Michael E. Mann is Director of the Earth System Science Center (ESSC) at Pennsylvania State University, and its mission statement reads, “the Earth System Science Center (ESSC) maintains a mission to describe, model, and understand the Earth's climate system.” Likewise, in Europe, Hans Joachim Schellnhuber, another leading climate scientist, is Founding Director of the Potsdam Institute for Climate Impact Research (PIK), which defines itself as a center in which scientists analyze the Earth System.
Earth system science (ESS) can be studied at a postgraduate level at some universities. In 1996, the American Geophysical Union, in cooperation with the Keck Geology Consortium and with support from five divisions within the National Science Foundation, convened a workshop "to define common educational goals among all disciplines in the Earth sciences." In its report, participants noted that, "The fields that make up the Earth and space sciences are currently undergoing a major advancement that promotes understanding the Earth as a number of interrelated systems." Recognizing the rise of this systems approach, the workshop report recommended that an Earth system science curriculum be developed with support from the National Science Foundation. In 2000, the Earth System Science Education Alliance was begun, and it describes itself as follows: "The Earth System Science Education Alliance (ESSEA) is a NASA, NSF and NOAA-supported program implemented by the Institute for Global Environmental Strategies (IGES) to improve the quality of geoscience instruction for pre-service and in-service K-12 teachers. Started in 2000, the program currently includes the participation of 40+ institutions, with over 3,000 teachers having completed an ESSEA course as of fall 2009."
The Science Education Resource Center, Carleton College, offers the following description of ESS: "Earth system science embraces chemistry, physics, biology, mathematics and applied sciences in transcending disciplinary boundaries to treat the Earth as an integrated system and seeks a deeper understanding of the physical, chemical, biological and human interactions that determine the past, current and future states of the Earth. Earth system science provides a physical basis for understanding the world in which we live and upon which humankind seeks to achieve sustainability."
Relationship to Gaia theory
It has been widely noted that Earth system science bears a kinship with Gaia theory, which states that the Earth self-regulates as the result of feedback loops, an emergent property of the physical environment and life together. Sir Crispen Tickell delivered the inaugural T. H. Huxley Lecture at Imperial College, London in 2007 on the subject of this kinship, and in his lecture, “Earth System Science: Gaia and the human impact,” Tickell depicts them as largely synonymous: for example, he will speak of “the mechanisms by which Gaia, or the Earth System, regulates itself.” Others have suggested that use of the term Earth System is largely one of avoidance, of finding a more neutral name to avoid the hated metaphor: for example, John Gribbon has written that, “most scientists couldn’t bring themselves to use the name Gaia, preferring Earth System Science.”
There has been little disagreement about the importance - for Earth system Science, for Gaia theory, and for the relationship between them - of the Amsterdam Declaration on Global Change (2001). It was signed by more than 1,000 scientists, and thus represents the highest level of scientific consensus, and states near the outset, “The Earth system behaves as a single self-regulating system.” Even Toby Tyrrell, the author of a recent book purporting to disprove Gaia theory, noted in his book's opening chapter how, “The wording could have been lifted from one of Lovelock’s books,” and also said that this Declaration highlighted, “the degree to which Gaia has been accepted by a large part of the scientific community, including those in its higher echelons.” Since the Declaration clearly does not mention Gaia by name, it appears to be a tacit acknowledgment, on the part of one of the chief critics of Gaia theory, that the Earth system and Gaia are fundamentally the same thing.
The relationship between Earth system science and Gaia theory is not a case of two similar and related viewpoints running in parallel: there there is little debate that, historically speaking, Gaia theory preceded, and was formative in the development of, Earth system science: Roger Highfield put this succinctly, writing in the Telegraph about a special exhibition devoted to James Lovelock and his Gaia theory at the London Museum of Science (2014-2015), saying simply, “with Gaia, Earth system science was born.”
Lovelock himself, in The Vanishing Face of Gaia, wrote that “Earth system science arose from Gaia theory,” but nevertheless has also sought to distinguish his theory from ESS, both by calling ESS “boring” and by saying that ESS differs from Gaia theory by "refusing to see habitability as the goal for the self-regulation of the Earth’s climate and chemistry.”
In Earth System Analysis for Sustainability, a workshop report edited by leading German climatologist Hans Joachim Schellnhuber, Nobel laureate Paul Crutzen and others, Chapter 2 states, while discussing the Earth system and Gaia:
“Much of the apparent disagreement over Gaia can be seen as a disagreement about how to talk about the system rather than a more fundamental discrepancy between the theoretical frameworks used to understand it.”
The primary text of the Amsterdam Declaration on Global Change runs as follows :
"The scientific communities of four international global change research programmes — the International Geosphere-Biosphere Programme (IGBP), the International Human Dimensions Programme on Global Environmental Change (IHDP), the World Climate Research Programme (WCRP) and the international biodiversity programme Diversitas — recognise that, in addition to the threat of significant climate change, there is growing concern over the ever-increasing human modification of other aspects of the global environment and the consequent implications for human well-being.
"The programmes have stated the following:
Research carried out over the past decade under the auspices of the four programmes to address these concerns has shown that:
- The Earth System behaves as a single, self-regulating system with physical, chemical, biological, and human components. The interactions and feedbacks between the component parts are complex and exhibit multi-scale temporal and spatial variability. The understanding of the natural dynamics of the Earth System has advanced greatly in recent years and provides a sound basis for evaluating the effects and consequences of human-driven change.
- Human activities are significantly influencing Earth's environment in many ways in addition to greenhouse gas emissions and climate change. Anthropogenic changes to Earth's land surface, oceans, coasts and atmosphere and to biological diversity, the water cycle and biogeochemical cycles are clearly identifiable beyond natural variability. They are equal to some of the great forces of nature in their extent and impact. Many are accelerating. Global change is real and is happening now.
- Global change cannot be understood in terms of a simple cause and effect paradigm. Human-driven changes cause multiple effects that cascade through the Earth System in complex ways. These effects interact with each other and with local- and regional-scale changes in multidimensional patterns that are difficult to understand and even more difficult to predict.
- Earth System dynamics are characterised by critical thresholds and abrupt changes. Human activities could inadvertently trigger such changes with severe consequences for Earth's environment and inhabitants. The Earth System has operated in different states over the last half million years, with abrupt transitions (a decade or less) sometimes occurring between them. Human activities have the potential to switch the Earth System to alternative modes of operation that may prove irreversible and less hospitable to humans and other life. The probability of a human-driven abrupt change in Earth's environment has yet to be quantified but is not negligible.
- In terms of some key environmental parameters, the Earth System has moved well outside the range of the natural variability exhibited over the last half million years at least. The nature of changes now occurring simultaneously in the Earth System, their magnitudes and rates of change are unprecedented. The Earth is currently operating in a no-analogue state."
Studies related to the discipline are published in the open-access journal Earth Perspectives . and in the Journal of Earth System Science, formerly titled Proceedings of the Indian Academy of Sciences (Earth and Planetary Sciences).
- Kasting, James. "The Gaia Hypothesis is Still Giving Us Feedback". Nautilus. Retrieved 25 July 2015.
- Mann, Michael. "Earth System Science Center". Penn State University. Retrieved 25 July 2015.
- "Shaping the Future of Undergraduate Earth Science Education". American Geophysical Union. Retrieved 2009-05-12.[dead link]
- "Earth System Science Education Alliance". Retrieved 25 July 2015.
- "Earth System Science in a Nutshell". Carleton College. Retrieved 2009-03-10.
- Tickell, Crispin. "Earth System Science: Gaia and the human impact". http://www.crispintickell.com/. Retrieved 25 July 2015.
- Gribbon, John and Mary (2009). James Lovelock: In Search of Gaia. Princeton, NJ: Princeton University Press.
- Tyrrell, Toby (2013). On Gaia: A Criticial Investigation of the Relationship Between Life and Earth. Princeton: Princeton University Press.
- Highfield, Roger. "Unlocking Lovelock, science's greatest maverick". The Telegraph. The Telegraph. Retrieved 25 July 2015.
- Lovelock, James (2009). The Vanishing Face of Gaia: A Final Warning. New York, NY: Basic Books.
- Schellnhuber, Hans et al. (2004). Earth System Analysis for Sustainability: Dahlem Workshop Reports. Massachusetts Institute of Technology & Freie Universitat Berlin.
- "Earth Perspectives".
- "Journal of Earth System Science". Springer (co-publisher). Retrieved 2009-03-10.