scholarly journals How does the Earth system generate and maintain thermodynamic disequilibrium and what does it imply for the future of the planet?

2012 ◽  
Vol 370 (1962) ◽  
pp. 1012-1040 ◽  
Author(s):  
Axel Kleidon
Keyword(s):  
Free Energy ◽  
Human Activity ◽  
Climate Models ◽  
Net Primary Productivity ◽  
Second Law Of Thermodynamics ◽  
Global Changes ◽  
Earth System ◽  
Geochemical Composition ◽  
The Earth ◽  
The Future

The Earth's chemical composition far from chemical equilibrium is unique in our Solar System, and this uniqueness has been attributed to the presence of widespread life on the planet. Here, I show how this notion can be quantified using non-equilibrium thermodynamics. Generating and maintaining disequilibrium in a thermodynamic variable requires the extraction of power from another thermodynamic gradient, and the second law of thermodynamics imposes fundamental limits on how much power can be extracted. With this approach and associated limits, I show that the ability of abiotic processes to generate geochemical free energy that can be used to transform the surface–atmosphere environment is strongly limited to less than 1 TW. Photosynthetic life generates more than 200 TW by performing photochemistry, thereby substantiating the notion that a geochemical composition far from equilibrium can be a sign for strong biotic activity. Present-day free energy consumption by human activity in the form of industrial activity and human appropriated net primary productivity is of the order of 50 TW and therefore constitutes a considerable term in the free energy budget of the planet. When aiming to predict the future of the planet, we first note that since global changes are closely related to this consumption of free energy, and the demands for free energy by human activity are anticipated to increase substantially in the future, the central question in the context of predicting future global change is then how human free energy demands can increase sustainably without negatively impacting the ability of the Earth system to generate free energy. This question could be evaluated with climate models, and the potential deficiencies in these models to adequately represent the thermodynamics of the Earth system are discussed. Then, I illustrate the implications of this thermodynamic perspective by discussing the forms of renewable energy and planetary engineering that would enhance the overall free energy generation and, thereby ‘empower’ the future of the planet.

6. Projection

2016 ◽  
pp. 91-106
Author(s):  
Tim Lenton
Keyword(s):  
Climate Change ◽  
Human Activities ◽  
Global Changes ◽  
Earth System ◽  
System Models ◽  
The Earth ◽  
The Future ◽  
Earth System Models ◽  
Specific Challenge

Where is the Earth system heading in the Anthropocene? To even begin to answer this question requires a model of how the Earth system works, and the answer depends on our collective activities as a species, and how the Earth system responds to those. The model’s role is to forecast the consequences of different assumptions about future human activities. ‘Projection’ introduces ‘Earth system models’ and some of the crucial assumptions that go into using them to forecast the future. It outlines their projections, going from shorter to longer timescales, and from the specific challenge of projecting climate change to the broader challenge of exploring other global changes.

Climate-vegetation-fire interactions and feedbacks: trivial detail or major barrier to projecting the future of the Earth system?

2016 ◽  
Vol 7 (6) ◽  
pp. 910-931 ◽  
Author(s):  
Rebecca M. B. Harris ◽  
Tomas A. Remenyi ◽  
Grant J. Williamson ◽  
Nathaniel L. Bindoff ◽  
David M. J. S. Bowman
Keyword(s):  
Earth System ◽  
Major Barrier ◽  
The Earth ◽  
The Future

scholarly journals Advances in Collaborative Documentation Support for CMIP6

2020 ◽  
Author(s):  
Charlotte Pascoe ◽  
David Hassell ◽  
Martina Stockhause ◽  
Mark Greenslade
Keyword(s):  
Science Communication ◽  
Scientific Community ◽  
Climate Models ◽  
Coupled Model ◽  
Automatic Generation ◽  
Earth System ◽  
The Earth ◽  
Data Citation ◽  
On Line ◽  
Intercomparison Project

<div>The Earth System Documentation (ES-DOC) project aims to nurture an ecosystem of tools & services in support of Earth System documentation creation, analysis and dissemination. Such an ecosystem enables the scientific community to better understand and utilise Earth system model data.</div><div>The ES-DOC infrastructure for the Coupled Model Intercomparison Project Phase 6 (CMIP6) modelling groups to describe their climate models and make the documentation available on-line has been available for 18 months, and more recently the automatic generation of documentation of every published simulation has meant that every CMIP6 dataset within the Earth System Grid Federation (ESGF) is now immediately connected to the ES-DOC description of the entire workflow that created it, via a “further info URL”.</div><div>The further info URL is a landing page from which all of the relevant CMIP6 documentation relevant to the data may be accessed, including experimental design, model formulation and ensemble description, as well as providing links to the data citation information.</div><div>These DOI landing pages are part of the Citation Service, provided by DKRZ. Data citation information is also available independently through the ESGF Search portal or in the DataCite search or Google’s dataset search. It provides users of CMIP6 data with the formal citation that should accompany any use of the datasets that comprise their analysis.</div><div>ES-DOC services and the Citation Service form a CMIP6 project  collaboration, and depend upon structured documentation provided by the scientific community. Structured scientific metadata has an important role in science communication, however it’s creation and collation exacts a cost in time, energy and attention.  We discuss progress towards a balance between the ease of information collection and the complexity of our information handling structures.</div><div> </div><div>CMIP6: https://pcmdi.llnl.gov/CMIP6/</div><div>ES-DOC: https://es-doc.org/</div><div>Further Info URL: https://es-doc.org/cmip6-ensembles-further-info-url</div><div> <p>Citation Service: http://cmip6cite.wdc-climate.de</p> </div>

The Archaeology of Global Environment Change

2013 ◽  
Author(s):  
Carole L. Crumley
Keyword(s):  
Human Activity ◽  
Global Environmental Change ◽  
Earth System ◽  
Human Environment ◽  
The Past ◽  
The Earth ◽  
Global Environmental ◽  
Urgent Task ◽  
The Two Cultures ◽  
Non Linear System

Recent, widely recognized changes in the Earth system are, in effect, changes in the coupled human–environment system. We have entered the Anthropocene, when human activity—along with solar forcing, volcanic activity, precession, and the like—must be considered a component (a ‘driver’) of global environmental change (Crutzen and Stoermer 2000; Levin 1998). The dynamic non-linear system in which we live is not in equilibrium and does not act in a predictable manner (see Fairhead, chapter 16 this volume for further discussion of non-equilibrium ecology). If humankind is to continue to thrive, it is of utmost importance that we identify the ideas and practices that nurture the planet as well as our species. Our best laboratory for this is the past, where long-, medium-, and short-term variables can be identified and their roles evaluated. Perhaps the past is our only laboratory: experimentation requires time we no longer have. Thus the integration of our understanding of human history with that of the Earth system is a timely and urgent task. Archaeologists bring two particularly useful sets of skills to this enterprise: how to collaborate, and how to learn from the past. Archaeology enjoys a long tradition of collaboration with colleagues in both the biophysical sciences and in the humanities to investigate human activity in all planetary environments. Archaeologists work alongside one another in the field, live together in difficult conditions, welcome collaboration with colleagues in other disciplines—and listen to them carefully—and tell compelling stories to an interested public. All are rare skills and precious opportunities. Until recently few practitioners of biophysical, social science, and humanities disciplines had experience in cross-disciplinary collaboration. Many scholars who should be deeply engaged in collaboration to avert disaster (for example, specialists in tropical medicine with their counterparts in land use change) still speak different professional ‘languages’ and have very different traditions of producing information. C. P. Snow, in The Two Cultures (1993 [1959]), was among the first to warn that the very structure of academia was leading to this serious, if unintended, outcome.

Syndication of the earth system: the future of geoscience?

2003 ◽  
Vol 6 (5) ◽  
pp. 457-463 ◽  
Author(s):  
Scott M. Elliott ◽  
Howard P. Hanson
Keyword(s):  
Earth System ◽  
The Earth ◽  
The Future

An overview of geoengineering of climate using stratospheric sulphate aerosols

2008 ◽  
Vol 366 (1882) ◽  
pp. 4007-4037 ◽  
Author(s):  
Philip J Rasch ◽  
Simone Tilmes ◽  
Richard P Turco ◽  
Alan Robock ◽  
Luke Oman ◽  
...  
Keyword(s):  
Ozone Depletion ◽  
Climate Models ◽  
Regional Climate ◽  
Ultraviolet B ◽  
Earth System ◽  
The Earth ◽  
Sulphur Cycle ◽  
Sulphate Aerosols ◽  
The Impact ◽  
Sulphur Species

We provide an overview of geoengineering by stratospheric sulphate aerosols. The state of understanding about this topic as of early 2008 is reviewed, summarizing the past 30 years of work in the area, highlighting some very recent studies using climate models, and discussing methods used to deliver sulphur species to the stratosphere. The studies reviewed here suggest that sulphate aerosols can counteract the globally averaged temperature increase associated with increasing greenhouse gases, and reduce changes to some other components of the Earth system. There are likely to be remaining regional climate changes after geoengineering, with some regions experiencing significant changes in temperature or precipitation. The aerosols also serve as surfaces for heterogeneous chemistry resulting in increased ozone depletion. The delivery of sulphur species to the stratosphere in a way that will produce particles of the right size is shown to be a complex and potentially very difficult task. Two simple delivery scenarios are explored, but similar exercises will be needed for other suggested delivery mechanisms. While the introduction of the geoengineering source of sulphate aerosol will perturb the sulphur cycle of the stratosphere signicantly, it is a small perturbation to the total (stratosphere and troposphere) sulphur cycle. The geoengineering source would thus be a small contributor to the total global source of ‘acid rain’ that could be compensated for through improved pollution control of anthropogenic tropospheric sources. Some areas of research remain unexplored. Although ozone may be depleted, with a consequent increase to solar ultraviolet-B (UVB) energy reaching the surface and a potential impact on health and biological populations, the aerosols will also scatter and attenuate this part of the energy spectrum, and this may compensate the UVB enhancement associated with ozone depletion. The aerosol will also change the ratio of diffuse to direct energy reaching the surface, and this may influence ecosystems. The impact of geoengineering on these components of the Earth system has not yet been studied. Representations for the formation, evolution and removal of aerosol and distribution of particle size are still very crude, and more work will be needed to gain confidence in our understanding of the deliberate production of this class of aerosols and their role in the climate system.

scholarly journals The global dust cycle and uncertainty in CMIP5 (Coupled Model Intercomparison Project phase 5) models

2020 ◽  
Vol 20 (17) ◽  
pp. 10401-10425
Author(s):  
Chenglai Wu ◽  
Zhaohui Lin ◽  
Xiaohong Liu
Keyword(s):  
Wet Deposition ◽  
Climate Models ◽  
Dust Emission ◽  
Coupled Model ◽  
Dust Particles ◽  
Earth System ◽  
Model Intercomparison ◽  
Dust Deposition ◽  
The Earth ◽  
Intercomparison Project

Abstract. The dust cycle is an important component of the Earth system and has been implemented in climate models and Earth system models (ESMs). An assessment of the dust cycle in these models is vital to address their strengths and weaknesses in simulating dust aerosol and its interactions with the Earth system and enhance the future model developments. This study presents a comprehensive evaluation of the global dust cycle in 15 models participating in the fifth phase of the Coupled Model Intercomparison Project (CMIP5). The various models are compared with each other and with an aerosol reanalysis as well as station observations. The results show that the global dust emission in these models varies by a factor of 4–5 for the same size range. The models generally agree with each other and observations in reproducing the “dust belt”, which extends from North Africa, the Middle East, Central and South Asia to East Asia, although they differ greatly in the spatial extent of this dust belt. The models also differ in other dust source regions such as North America and Australia. We suggest that the coupling of dust emission with dynamic vegetation can enlarge the range of simulated dust emission. For the removal process, all the models estimate that wet deposition is smaller than dry deposition and wet deposition accounts for 12 %–39 % of total deposition. The models also estimate that most (77 %–91 %) dust particles are deposited onto continents and 9 %–23 % of dust particles are deposited into oceans. Compared to the observations, most models reproduce the dust deposition and dust concentrations within a factor of 10 at most stations, but larger biases by more than a factor of 10 are also noted at specific regions and for certain models. These results highlight the need for further improvements of the dust cycle especially on dust emission in climate models.

The Strata Machine

2008 ◽  
Author(s):  
Jan Zalasiewicz
Keyword(s):  
Human Activity ◽  
Chicago Tribune ◽  
The Earth ◽  
The Future ◽  
Henry Ford ◽  
Tangible Evidence ◽  
History Of ◽  
Inert Mass ◽  
Resource Exhaustion ◽  
The Many

History is bunk—or so Henry Ford is reputed to have said. Folk memory, though, simplifies recorded statements. What Henry Ford actually told the Chicago Tribune was ‘History is more or less bunk. It’s tradition. We don’t want tradition. We want to live in the present, and the only tradition that is worth a tinker’s damn is the history that we make today.’ So folk memory, in this case, did pretty well reflect the kernel of his views. Henry Ford also said that ‘Exercise is bunk. If you are healthy, you don’t need it; if you are sick, you shouldn’t take it.’ Henry Ford was a very powerful, very rich man of strongly expressed views. And he was quite wrong on both counts. Not having known Henry Ford, interplanetary explorers may have their own view of history. As, perhaps, an indispensable means of understanding the present and of predicting the future. As a way of deducing how the various phenomena—physical, chemical, and biological—on any planet operate. And as a means of avoiding the kind of mistake—such as resource exhaustion or intra-species war—that could terminate the ambitions of any promising and newly emerged intelligent life-form. On Earth, and everywhere else, things are as they are because they have developed that way. The history of that development must be worked out from tangible evidence: chiefly the objects and traces of past events and processes preserved on this planet itself. The surface of the Earth is no place to preserve deep history. This is in spite of—and in large part because of—the many events that have taken place on it. The surface of the future Earth, one hundred million years from now, will not have preserved evidence of contemporary human activity. One can be quite categorical about this. Whatever arrangement of oceans and continents, or whatever state of cool or warmth will exist then, the Earth’s surface will have been wiped clean of human traces. For the Earth is active. It is not just an inert mass of rock, an enormous sphere of silicates and metals to be mined by its freight of organisms, much as caterpillars chew through leaves.

scholarly journals Plant physiological ecology and the global changes

2012 ◽  
Vol 36 (3) ◽  
pp. 253-269 ◽  
Author(s):  
João Paulo Rodrigues Alves Delfino Barbosa ◽  
Serge Rambal ◽  
Angela Maria Soares ◽  
Florent Mouillot ◽  
Joana Messias Pereira Nogueira ◽  
...  
Keyword(s):  
Physiological Ecology ◽  
System Change ◽  
Global Changes ◽  
Earth System ◽  
Real Effects ◽  
Physiological Processes ◽  
The Earth ◽  
Plant Physiological Ecology ◽  
Biophysical Processes ◽  
And Function

The global changes are marked by alteration on the normal patterns of important biochemical and biophysical processes of the Earth. However, the real effects as well as the feedbacks of the global changes over vegetation are still unclear. Part of this uncertainty can be attributed to the inattention of stakeholders and scientists towards vegetation and its complex interrelations with the environment, which drive plant physiological processes in different space-time scales. Notwithstanding, some key subjects of the global changes could be better elucidated with a more plant physiological ecology approach. We discuss some issues related to this topic, going through some limitations of approaching vegetation as a static component of the biosphere as the other sub-systems of the Earth-system change. With this perspective, this review is an initial reflection towards the assessment of the role and place of vegetation structure and function in the global changes context. We reviewed the Earth-system and global changes terminology; attempted to illustrate key plant physiological ecology researches themes in the global changes context; consider approaching plants as complex systems in order to adequately quantify systems characteristics as sensibility, homeostasis, and vulnerability. Moreover, we propose insights that would allow vegetation studies and scaling procedures in the context of the Earth-system. We hope this review will assist researchers on their strategy to identify, understand and anticipate the potential effects of global changes over the most vulnerable vegetation processes from the leaf to the global levels.

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