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From the Deep, a monthly newsletter from DCO
March 2017
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Deep Carbon Observatory
Third DCO International Science Meeting

From 23-25 March 2017, more than 150 members of the DCO Science Network met at the University of St Andrews for the Third DCO International Science Meeting. Read more about the meeting here.

Letter from the Director


The Third DCO International Science Meeting featured major advances in deep carbon science. The meeting, which took place at the University of St Andrews, Scotland from 23-25 March 2017, “flipped” meeting norms, with many early and mid-career scientists delivering oral presentations and many senior scientists giving poster presentations. This strategy provided opportunities for all participants to learn about early career scientists' research during the plenary sessions, while creating opportunities for one-on-one interactions between senior and early career scientists at the poster sessions. 
We are especially grateful to Chris Ballentine (University of Oxford, UK) for serving as chair of the Science Program Committee and Sami Mikhail (University of St Andrews, UK) for serving as local host for the Third DCO International Science Meeting. The meeting provided a glimpse of how much has been accomplished since DCO’s inception in 2009. It also served as a prelude to synthesis activities.
The Deep Carbon Observatory is dedicated to supporting the scientific and professional development of early career scientists, who embody the future of deep carbon science. We encourage DCO early career scientists to apply for exciting opportunities in Italy in summer, fall, and winter:
Third DCO Early Career Scientist Workshop at Mt. Etna, Italy
Ph.D. School on Carbon Forms, Paths and Processes in Como, Italy
International Diamond School in Bressanone, Italy, 2018
Congratulations to Maggie CY Lau (Princeton University, USA) and Yves Moussallam (University of Cambridge, UK), who received DCO Emerging Leader Awards for their outstanding contributions to deep carbon science and unique potential as future leaders of the DCO community.
We’d also like to encourage members of the DCO Science Network to propose deep carbon science technical sessions at the 2017 AGU Fall Meeting in New Orleans by 19 April 2017 and submit abstracts to the many deep carbon sessions at the 2017 Goldschmidt Conference in Paris by 1 April 2017.

Craig Schiffries, DCO Director
Carnegie Institution for Science, Geophysical Laboratory
Washington DC, USA

News Features

First-Ever Catalog of 208 Human-Caused Minerals Bolsters Argument to Declare ‘Anthropocene Epoch’
Human industry and ingenuity has done more to diversify and distribute minerals on Earth than any development since the rise of oxygen over 2.2 billion years ago. Recent research bolsters the scientific argument to officially designate a new geological time interval distinguished by the pervasive impact of human activities: the Anthropocene Epoch. In a paper, published by American Mineralogist, a team led by Robert Hazen (Carnegie Institution for Science, USA) identifies for the first time a group of 208 mineral species that originated either principally or exclusively due to human activities. That’s almost 4% of the roughly 5,200 minerals officially recognized by the International Mineralogical Association (IMA). Read more...

Researchers Delineate Factors Controlling Formation of Subsurface Methane
The groundwaters bathing crystalline bedrock, shaped by high temperatures and extreme pressures, can have surprisingly high concentrations of methane, even in places where ancient organic carbon has transformed into graphite or other inorganic forms. Researchers are exploring the sources of this methane to figure out how it is produced and its role in the deep carbon cycle. Riikka Kietäväinen, a member of DCO’s Deep Energy and Deep Life Communities, along with Lasse Ahonen, also a member of the Deep Life Community, (both at the Geological Survey of Finland, in Espoo), and colleagues investigated factors that control methane formation at two sites in Finland: the Outokumpu Deep Drill Hole and the Pyhäsalmi copper-zinc mine, which both extend about 2.5 kilometers into Precambrian bedrock. In a new paper in Geochimica et Cosmochimica Acta, the researchers combine isotopic measurements from water, gas, and minerals sampled from the two sites with existing chemical and microbiological analyses. Read more...

Half of Carbon Transported to Mid-Ocean Ridges Remains Trapped Below
Much of the volcanic activity happening on Earth occurs where we can’t see it, in a network of mid-ocean ridges running along the bottom of the world’s oceans. As tectonic forces pull oceanic plates apart, they pull hot rocks up from the mantle. Some of these rocks melt in the process, producing magma that flows upward to fill the rift between the spreading plates with newly formed oceanic crust. Researchers thought that this process efficiently moves deep carbon, carried by the magma, and releases it into the ocean. But a new simulation study finds that up to half of the carbon initially removed from mantle rocks remains trapped below the oceanic plates. Tobias Keller (Stanford University, USA), Richard Katz (University of Oxford, UK), and Marc Hirschmann (University of Minnesota, USA), members of the DCO Reservoirs and Fluxes and Modeling and Visualization communities, simulated the global carbon output from mid-ocean ridges using a recently developed model of carbon transport in the mantle. While their simulations match existing estimates of global carbon release, they find that the carbon that doesn’t erupt crystallizes along with deep water that behaves similarly, in a layer at the base of the lithosphere, the plate-like part of Earth’s uppermost mantle. They publish their results in a recent paper in Earth and Planetary Science Letters. Read more...

Microbial Communities in Serpentinites Make the Best of a Difficult Situation
Serpentinite environments, like the Lost City hydrothermal field in the mid-Atlantic, have received much attention in recent years as potential cradles of life on Earth, and as analogs for sites that could support life on Mars. Microbes thrive on compounds released by reactions between serpentinizing minerals and seawater in hydrothermal vents. The submarine location of these sites, however, presents many challenges for scientists trying to study them. The Coast Range Ophiolite Microbial Observatory (CROMO), located in northern California, is a serpentinization site that once lay at the bottom of the seafloor. Its current landlocked location allows researchers to study the geochemistry and microbiology of a serpentinization site in great detail. In a new paper, DCO members Katrina Twing and William Brazelton, (both at University of Utah Salt Lake City, USA), Matthew Schrenk (Michigan State University, USA), Michael Kubo (SETI Institute, USA), Dawn Cardace (University of Rhode Island, USA), Tori Hoehler (NASA Ames Research Center, USA) and Tom McCollom (University of Colorado Boulder, USA) describe the geochemical factors affecting microbial communities at seven wells drilled into the freshwater aquifer within serpentinite rocks at CROMO. While the site provides easy access for scientists, it is a difficult environment for microbes. The study appears in the DCO Early Career Scientist research topic of Frontiers in Microbiology. Read more...

A New Contender for the Title of Oldest Fossil
The discovery of fossilized microbes within ancient rocks that formed around submarine-hydrothermal vents provides evidence that life existed at least 3,770 million years ago. If confirmed, these would be the earliest known microfossils on Earth. In a new paper, DCO Deep Life Community members Matthew Dodd, Dominic Papineau (both at University College London, UK) and colleagues describe microfossils discovered in the Nuvvuagittuq Belt in Quebec, Canada. These newly found ancient fossils are similar in appearance to fossils of filamentous microbes in younger rocks as well as cells in modern hydrothermal vent environments. The researchers also provide isotopic and mineral evidence supporting a biological origin of these structures. Their findings appear in the journal Nature. Read more...

A New Piece of the Global Methane Puzzle
The first cells on Earth may have feasted on the byproducts of serpentinization, reactions between water and mantle rocks that, in the presence of carbon, may generate large amounts of methane and other organic compounds. Serpentinization reactions at shallow depths are the subject of intense research interest due to their possible contributions to life’s origins, but also because they play an important role in Earth’s carbon cycle. Now, a new study suggests that these same chemical reactions occur not just at the surface, but also deep beneath Earth’s crust, under conditions of high temperature and pressure. DCO Deep Energy Community members Alberto Vitale Brovarone (Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, France) Isabelle Martinez (Institut de Physique du Globe de Paris, France), and colleagues studied rock samples from the Lanzo Massif in the Western Alps. The analysis shows that serpentinization reactions deep down can generate methane at rates that are comparable to shallow serpentinization environments. The researchers report their findings in a new paper in Nature Communications. Read more...

Extreme Heat and Pressure May Yield Hydrocarbons in Earth’s Mantle
All scientists strive to shed light on difficult questions, but researchers who study deep carbon face the additional challenge of illuminating a very dark place indeed: hundreds of kilometers beneath Earth’s surface. With the deepest boreholes reaching little farther than 12 kilometers, researchers must rely on theoretical calculations and lab simulations to understand the high-temperature and high-pressure reactions occurring deep within the mantle. In a new review in ChemistrySelects, three Deep Carbon Observatory researchers synthesize theory, computer modeling, and lab experiments to explain the chemical and physical processes that carbon undergoes in Earth’s upper mantle. Anton Kolesnikov (Gubkin Russian State University of Oil and Gas in Moscow) Vladimir Kutcherov (Royal Institute of Technology in Stockholm and Gubkin Russian State University of Oil and Gas), and John Saul (Swala Gem Traders, Arusha, Tanzania), draw on decades of research to explain the formation of hydrocarbons under “thermobaric” conditions, with extremely high temperatures and pressure levels. Read more...

Third DCO International Science Meeting in St Andrews, Scotland:
New Directions for Deep Carbon Science

More than 150 members of the Deep Carbon Observatory Science Network gathered at the University of St Andrews, Scotland to present forefront research on deep carbon science at the Third DCO International Science Meeting from 23-25 March 2017. The interdisciplinary meeting explored DCO’s scientific advances into the quantities, movements, forms, and origins of deep carbon. Organized by the DCO Secretariat, the three-day meeting consisted of intensive oral presentations, poster sessions, and workshops. Read more...

Blog: Embers Alight on the Trail By Fire 1.5!
As the Trail by Fire team prepares to leave Ecuador, we have a moment to reflect upon the freeways and road blocks we’ve encountered while traveling more than 20,000 km and visiting more than 20 volcanoes of the Nazca subduction zone. It has been said that “success is the ability to move from one failure to another without loss of enthusiasm.” Well, it’s never been quite as bad as that on the Trail, but there have been some challenges. Read more...

APPLY NOW: Third DCO Early Career Scientist Workshop to Study Mt. Etna
The Deep Carbon Observatory, in collaboration with the Department of Earth Sciences of Sapienza University (Rome), is hosting its third Early Career Scientist Workshop in Nicolosi (Etna), Italy, 28 August-2 September 2017. This workshop will bring together the next generation of researchers active in deep carbon studies from around the world. Building on the success of the first and second DCO Early Career Scientist Workshops, this third workshop of early career researchers will continue to foster collaboration and community within the ever expanding DCO Science Network. Read more... 

APPLY NOW: PhD School on Carbon Forms, Paths, and Processes in Earth
The international school will present state-of-the-art of research studying the forms, paths, and processes of carbon in Earth in order to address the long-term fate of carbon on the planet. The school will consist of a series of invited lectures, practical sessions on cutting-edge techniques, and contributions from participants. This five-day school is intended to bring together scientists, PhD students, and postdocs with broad international representation in geochemistry, petrology, experimental mineralogy and petrology, materials science, thermodynamics, volcanology, geodynamics, and geophysics. The school will take place from 15-20 October 2017 at the Villa del Grumello, Como, Italy. Read more...

APPLY NOW: Fourth International Diamond School
The school will provide a general overview of the recent advances in diamond research, combining geology, exploration, and gemology of diamond, providing theoretical lectures and practical sessions focused on microscope observations of a complete inclusion-bearing diamond collection and micro-Raman spectroscopy analyses.  Masters students, PhD students, and senior researchers of any research fields are welcome to apply to the school, which will take place at the Università di Padova, Bressanone-Brixen (Bolzano-Bozen, Italy) from 29 January - 2 February 2018. Read more...

Upcoming Events

Mineral Evolution Exhibit, Vienna, Austria, 5 April 2017
A new mineral evolution exhibit opens at the Natural History Museum Vienna, Austria on Tuesday 5 April 2017. Inspired by the work of DCO Executive Director Robert Hazen, the exhibit will become part of the museum's permanent collection, combining objects that document the development of Earth in connection with 56 minerals illustrating the evolution of minerals.

EGU General Assembly, Vienna, Austria, 23-28 April 2017
The European Geosciences Union General Assembly 2017 will bring together geoscientists from all over the world to one meeting covering all disciplines of Earth, planetary, and space sciences. 

Deep Continental Drilling into the Moho in the Ivrea-Verbano Zone ICDP Workshop, Baveno, Italy, 2-5 May 2017
This workshop is aimed at developing a strategic plan for drilling into the continental crust-mantle transition in the Ivrea-Verbano Zone. 

JpGU-AGU Joint Meeting, Makuhari Messe, Japan, 20-25 May 2017
In May 2017, the Japan Geoscience Union and the American Geophysical Union will hold the first joint meeting of the two societies. More than 50 sessions, covering all areas of the Earth and space sciences, will be presented in English for inter- and trans-disciplinary scientists. 

Goldschmidt 2017, Paris, France, 13-18 August 2017
Goldschmidt, the foremost annual, international conference on geochemistry and related subjects, will be held in Paris in 2017. View sessions of interest to DCO. Abstract submission deadline: 1 April 2017

IAVCEI 2017 Scientific Assembly, Portland, Oregon, USA, 14-18 August 2017
This conference will cover planetary volcanology and chemistry of Earth's interior and eruption dynamics, including a practical understanding of the environmental and social impacts of eruptions. 

Third DCO Early Career Scientist Workshop, Etna, Italy, 28 August-2 September 2017
This workshop will bring together the next generation of researchers active in deep carbon studies from around the world. Application deadline: 14 April 2017

PhD School, Como, Italy, 15-20 October 2017
The aim of the school is to present state of the art of research on the forms, paths, and processes of carbon in Earth in order to address the long-term fate of carbon on the planet. Application deadline: 15 June 2017 

2017 GSA Annual Meeting, Seattle, Washington, USA 22-25 October 2017
Seattle, Washington, is the location for the annual meeting of the Geological Society of America and includes opportunities for local field experiences.

AGU Fall Meeting, New Orleans, 11-15 December 2017 
AGU’s Fall Meeting is the largest Earth and space science meeting in the world. Session proposal deadline: 19 April 2017 

Fourth International Diamond School, Bolzano-Bozen, Italy, 29 January - 2 February 2018
The school will provide a general overview of the recent advances in diamond research, combining geology, exploration, and gemology of diamond. Pre-registration now open.

Honors and Awards

Maggie CY Lau, Deep Life/Deep Energy
Princeton University, USA
2017 DCO Emerging Leader Award

Yves Moussallam, Reservoirs and Fluxes
University of Cambridge, UK
2017 DCO Emerging Leader Award

Kai-Uwe Hinrichs, Deep Life Co-Chair
MARUM University of Bremen, Germany
2017 Geochemical Fellow

Sami Mikhail, Reservoirs and Fluxes
University of St Andrews, UK
2017 Murchison Fund from the Geological Society of London

Funding Opportunities

IODP: Submit an IODP Drilling Proposal
The Proposal Database System (PDB) is a web-based interface for completing and submitting IODP proposals. Potential submitters are advised to begin working with PDB as soon as a proposal is planned. Complete proposal preparation guidance, format requirements, and review policies are explained in the IODP Proposal Submission Guidelines. A Call for Scientific Ocean Drilling Proposals is usually published at least two months in advance of the deadline with specifics about what types of proposals are being sought. Proponents are strongly encouraged to contact the Science Operators to discuss platform-specific operational and fiscal constraints before developing proposals. Next proposal submission deadline: 3 April 2017

Census of Deep Life Sequencing Opportunities: Request for Proposals
Since 2011, the Deep Carbon Observatory’s Deep Life Community has sponsored the Census of Deep Life (CoDL) that has supported surveys of the diversity of microbes present in several deep continental and subseafloor environments. The first surveys (2011-2012) were conducted using 454 pyrosequencing and subsequently (2013) Illumina sequencing strategies were adopted. Through this initiative, the Deep Life Community has allowed the characterization of diversity of subsurface microbial communities at numerous sites worldwide, including the subseafloor and deep continental locations from a range of geologic settings (e.g., large igneous provinces, subglacial lakes, methane hydrate-rich sediments, cratons). The Illumina platform provides increased numbers of reads for more samples at reduced cost. For DNA samples submitted to the CoDL for sequencing, proponents have the option of obtaining 400-450 nt sequences that span the V4V5 region of Bacterial and Archaeal rRNA coding regions or a greater number of reads for V6 regions that through complete overlap of forward and reverse reads allows detection of lower abundance taxa with reduced stochastic error rates. Shotgun metagenomic DNA sequencing for key samples can also be performed. This call for proposals aims to support sequencing that represents expanded analyses from ongoing Deep Life Community projects or projects that represent sites and investigators new to the DCO’s Deep Life Community. Proposal deadline: 30 April 2017

C-DEBI: Rolling call for Research Exchange proposals
C-DEBI facilitates scientific coordination and collaborations by supporting student, postdoctoral, and faculty exchanges to build, educate, and train the deep subseafloor biosphere community. We award small research exchange grants for Center participants. These grants may be used to support research, travel for presenting C-DEBI research at meetings, or travel exchanges to other partner institutions or institutions that have new tools and techniques that can be applied to C-DEBI research. We anticipate ~10 awards of $500-5000 with additional matched funds to be granted annually. 

New Publications

View more papers in the DCO publications browser.

On the mineralogy of the “Anthropocene Epoch”
Robert M. Hazen, Edward S. Grew, Marcus J. Origlieri, and Robert T. Downs
American Mineralogist doi:10.2138/am-2017-5875

Evidence for early life in Earth’s oldest hydrothermal vent precipitates
Matthew S. Dodd, Dominic Papineau, Tor Grenne, John F. Slack, Martin Rittner, Franco Pirajno, Jonathan O’Neil, and Crispin T. S. Little
Nature doi:10.1038/nature21377

Abiotic and biotic controls on methane formation down to 2.5 km depth within the Precambrian Fennoscandian Shield
Riikka Kietäväinen, Lasse Ahonen, Paula Niinikoski, Hannu Nykänen, and Ilmo T. Kukkonen
Geochimica et Cosmochimica Acta doi:10.1016/j.gca.2016.12.020

Volatiles beneath mid-ocean ridges: Deep melting, channelised transport, focusing, and metasomatism
Tobias Keller, Richard F. Katz, and Marc M. Hirschmann
Earth and Planetary Science Letters doi:10.1016/j.epsl.2017.02.006

Massive production of abiotic methane during subduction evidenced in metamorphosed ophicarbonates from the Italian Alps
Alberto Vitale Brovarone, Isabelle Martinez, Agnès Elmaleh, Roberto Compagnoni, Carine Chaduteau, Cristiano Ferraris, and Imène Esteve
Nature Communications doi:10.1038/ncomms14134

Serpentinization-influenced groundwater harbors extremely low diversity microbial communities adapted to high pH
Katrina I. Twing, William J. Brazelton, Michael D. Y. Kubo, Alex J. Hyer, Dawn Cardace, Tori M. Hoehler, Tom M. McCollom, and Matthew O. Schrenk
Frontiers in Microbiology doi:10.3389/fmicb.2017.00308

Chemistry of hydrocarbons under extreme thermobaric conditions
Anton Yu. Kolesnikov, John M. Saul, and Vladimir G. Kutcherov
Chemistry Select doi:10.1002/slct.201601123

Employment Opportunities

PhD position at the University of Plymouth, UK
Although field studies of ophiolites have been critical for the development of our understanding of the ocean crust, they are limited to samples exposed at the surface. The ICDP Oman Drilling Project provides a unique set of cores from the lower crust to test end member models. This project will combine the high-resolution quantitative core logging typical of scientific ocean drilling with the outcrop scale context, providing an unrivaled opportunity to study the formation of the ocean crust. The student will become part of the international team of scientists investigating the Oman ophiolite and have opportunities to participate in fieldwork in Oman and onsite and core-logging activities (aboard the Chikyu/JOIDES Resolution). Application deadline: 30 April 2017

PhD positions in Geomicrobiology at the University of Pennsylvania, USA
The Department of Earth and Environmental Science and the Center for Energy Research at the University of Pennsylvania seek graduate students interested in any of the following research areas: geomicrobiology, ecology, microbe-microbe and microbe-mineral interactions, biogeochemistry, ecophysiology, and bioenergetics. The successful applicants will be awarded a PhD Fellowship package that includes: tuition, fees, health care, and stipend for living expenses. These packages are available starting Fall 2017.

DCO in the News

Read more DCO News here

13 March 2017: Smithsonian geologist digs up clues to Earth’s beginnings
By Kitson Jazynka for The Washington Post KidsPost
Elizabeth Cottrell travels to the Aleutian Islands, off mainland Alaska, to study volcanoes...

6 March 2017: Searching the deep biosphere for clues to extraterrestrial life
By Tullis C. Onstott for Scientific American Guest Blog
If life can thrive miles underground on Earth, it might be able to thrive in the subsurface on other worlds...

3 March 2017: Human activity on Earth triggered a new age of minerals
By David Bressan for Forbes
Today 5,000 to 7,000 minerals are formally recognized on earth and every year some new ones are discovered...

3 March 2017: You are living in a unique time on planet Earth — mineralogically speaking
By Deborah Netburn for The LA Times
Scientists say there are more unique minerals on our planet than ever before in its 4.5-billion-year history, and it’s thanks in part to us...

3 March 2017: Human-caused minerals: Another sure sign of the Anthropocene?
By Nathanial Scharping for Discover Magazine
To the ever-growing list of uniquely human tweaks to the planet, we can add the creation of 208 minerals...

2 March 2017: Human impact on the planet's chemistry has created a catalogue of new minerals in 'the blink of an eye', say scientists
By Tim Collins for The Daily Mail
Human activity has brought about the creation of a new group of inorganic compounds - virtually overnight in geological terms...

2 March 2017: Is the Anthropocene really a thing? Minerals we've helped create rekindle the debate.
By Mary Beth Griggs for Popular Science
Minerals have to meet certain criteria before they're deemed deserving of the name...

2 March 2017: Human activity helps create hundreds of new minerals
By Lucy Carter for ABC Radio
It took billions of years for most of the Earth's minerals to form, but scientists say hundreds more have been created in the years since the industrial revolution...

2 March 2017: Menschheit ließ 200 Mineralien neu entstehen
Mehr als 5200 Mineralien hat die Internationale Mineralogische Gesellschaft (IMA) offiziell anerkannt... 

2 March 2017: Uomo ha segnato nuova era geologica
Corriere Della Serra
L'attività dell'uomo ha davvero segnato una nuova era geologica, quella dell'Antropocene: lo si evince da come ha inciso sulla diversificazione e sulla distribuzione dei minerali del Pianeta...

1 March 2017: We've created 208 new minerals: Time for a new, human-influenced Anthropocene epoch?
By Nicole Mortillaro for CBC News
Humans have created 208 new minerals, bolstering the argument that the planet has entered a new epoch in its geological history, a study being published today finds...

1 March 2017: Anthropocene marked by mineral spike
BBC News
Scientists have identified 208 new minerals that owe their existence wholly or in part to humans...

1 March 2017: Humans have caused an explosion of never-before-seen minerals all over the Earth
By Chelsea Harvey for The Washington Post
The human handprint on the natural world has become evident in all too many ways in recent decades...

1 March 2017: El hombre ya ha creado 208 nuevos minerales, ¿es la señal de una nueva era?
ABC Ciencia
La industrialización y la actividad humana han destruido tantas especies y ecosistemas que se cree que estamos a las puertas del sexto evento de extinción masiva, después del causado por el asteroide que acabó con los dinosaurios...

1 March 2017: Minerals found in shipwreck and museum drawer 'show we are living in new epoch'
By Nicola Davis for The Guardian
Humans are leaving an indelible mark on the planet in a vast array of manmade crystals, researchers have revealed, adding weight to idea that we are living in a new geological epoch – the Anthropocene...

1 March 2017: Rock solid evidence of Anthropocene seen in 208 minerals we made
By Chelsea Whyte for New Scientist
The evidence of humans changing the planet is solid as rock...

1 March 2017: Found: Thousands of man-made minerals—Another argument for the Anthropocene
By Shannon Hall for Scientific American
Humans have dramatically changed Earth’s surface. Satellite images show New York City’s sparkling lights at night and the Great Wall of China during the day...


Learn more about DCO's Scientific Communities


Deep Life

The Deep Life Community is dedicated to assessing the nature and extent of the deep microbial and viral biosphere by exploring the evolutionary and functional diversity of Earth’s deep biosphere and its interaction with the carbon cycle.

Deep Energy

The Deep Energy Community is dedicated to developing a fundamental understanding of environments and processes that regulate the volume and rates of production of abiogenic hydrocarbons and other organic species in the crust and mantle through geological time.

Extreme Physics and Chemistry

The Extreme Physics and Chemistry Community is dedicated to improving our understanding of the physical and chemical behavior of carbon at extreme conditions, as found in the deep interiors of Earth and other planets.

Reservoirs and Fluxes

The Reservoirs and Fluxes Community is dedicated to identifying the principal deep carbon reservoirs, to determining the mechanisms and rates by which carbon moves among these reservoirs, and to assessing the total carbon budget of Earth.