Remarks by
Dr. Raymond L. Orbach
Director, Office of Science, U.S. Department of Energy
at the DOE/NETL Second Annual Carbon Sequestration Conference
Alexandria, VA
May 8, 2003

As Mike Smith said, we are a team, and what I will be talking to you about this morning are the activities of the Office of Science as part of that teamwork for the basic research that underpins carbon sequestration. It is a great pleasure to be here with you today, and the purpose of my talk is to encourage you to join with us in these research activities that are of interest to you and that I will be discussing this morning.

We expect there will be major transitions in energy technologies this century, including technologies for sequestering carbon from energy producing systems. Progress from fundamental research is needed to overcome barriers that impede the development of low-cost solutions for the far-reaching changes that will take place and to evaluate the environmental consequences of the potential technologies.

The Department’s Office of Science has had a sequestration research program since 1999. A roadmap that the Office of Science developed with the Office of Fossil Energy in 1999 helped initiate and scope the program.

The Office of Science supports carbon sequestration research in four major areas: 1) geologic sequestration, 2) terrestrial sequestration, 3) ocean sequestration, and 4) advanced biological and biotechnical approaches based on advances in genomic research, including research on the genome of plants and microorganisms.

If geological sequestration turns out to be effective – and you have heard already from Dr. Orr about his initiative – the potential will be substantial, and it will be relatively easy to measure. However, assuring that sequestering carbon in geologic formations is effective and permanent is very important and will require significant fundamental research advances.

This slide depicts the injection of carbon dioxide captured from a power plant into a saline formation.

The Office of Science has had a long-running Geosciences program that supports basic research that will form a stronger foundation of understanding for each of the four topical areas represented by the circles in this figure.

1) Scientists funded by the Office of Science are investigating the complex flow and mixing of multiphase fluids such as carbon dioxide and water. The goal is to predict the effect of CO2 injection on the pore fluids, telling us about the likely flow and the geological and hydrological stability of the depleted hydrocarbon reservoirs or saline formations into which CO2 is injected. So these are the microscopic calculations that will inform the models that Dr. Orr made reference to.

2) Another area of research is to understand the geochemical reactions between the carbon dioxide and formation minerals. If the CO2 is incorporated into minerals, it could provide permanent storage, but it could also make injection more difficult by clogging the flow pathways and thereby limiting the amount of CO2 that could be injected into a formation. This complex structure needs to be understood at the microscopic level.

3) A third area of research is to improve how we track the chemical reactions and hydrologic flow occurring in formations into which CO2 is injected to improve our performance assessment of storage capability. Research in this area also includes hydrological, mechanical, and chemical modeling of the physics of subsurface fluid flows.

4) Finally, Dr. Orr referred to monitoring, and geophysical imaging, as he mentioned, will be critical to monitor the location of the injected carbon dioxide. More needs to be known about how to detect where the carbon dioxide goes once it is injected into geologic formations and to image changes caused by the carbon dioxide to the formations that contain it.

All four of these areas of research are fundamental and we hope will provide basic information that will enable modeling and technological advances to develop.

As an example of basic research supported by the Office of Science that has led to applications supported by others, our Office supported computational research that provided the modeling groundwork for assessing the potential of carbon dioxide injection into the Frio Formation in Texas as part of the Office of Fossil Energy Geo-Sequestration project demonstration site.

A second area of carbon sequestration research supported by the Office of Science is terrestrial sequestration in soils and vegetation. As you just heard from Dr. Hohenstein of the U.S. Department of Agriculture, the quantities of “natural” carbon dioxide captured by the terrestrial biosphere from the atmosphere through plant photosynthesis and then reinjected back into the atmosphere through plant respiration and microbial respiration as dead plant material decomposes each year is about an order of magnitude greater than the amount of carbon dioxide contributed from human activities. Emissions from human activities include power plants, cement making, and land use changes. Any small tilt in the “natural” biological sequestration could make a large difference in the atmospheric concentration of carbon dioxide.

This figure illustrates one estimate of the tilt that could occur from actual and potential quantities of carbon sequestration absorbed by terrestrial ecosystems. Of the 7.7 gigatonnes of carbon emitted globally from the combustion of fossil fuel sources and land use change, the current natural processes of photosynthesis and organic matter formation result in net removal of between 1 and 2 gigatonnes of carbon from the atmosphere per year. The current global estimate is 1.7 gigatonnes. This quantity represents the net carbon sink (uptake minus release) of terrestrial ecosystems (the solid green arrow on the figure).

Enhancing the storage of carbon dioxide in the terrestrial biosphere requires that CO2 fixed from the atmosphere ends up in long-lived pools in forms that resist microbial decomposition. The potential to enhance the quantity of carbon sequestered in terrestrial ecosystems globally may be significant, as illustrated by the hashed arrows in this figure. The numbers shown here for the hashed arrows, however, are very rough estimates with major uncertainties as to what the full potential might be and how long it could be realized. These estimates are based on assumed changes in land use, land use management practices for forests, agriculture, and rangeland, crop management, and other factors. Enhancing terrestrial carbon sequestration and improving estimates of its potential will depend on new scientific information and optimized land management and land use practices.

The Office of Science funds a consortium of national laboratories, universities, and other federal institutions as a center referred to as the “Carbon Sequestration in Terrestrial Ecosystems” (CSiTE) consortium.

There are often ancillary benefits of sequestering carbon in the soil and increasing the amount of aboveground biomass that also contains carbon. A soil with more organic carbon, for example, can retain more water and may need less fertilizer.

The scientific issues being addressed by the terrestrial carbon sequestration research include:

· Understanding carbon capture and sequestration mechanisms in vegetation and soils, including how to increase the photosynthetic efficiency of plants to fix more carbon dioxide and how to promote the formation of long-lived pools of soil organic matter where the carbon will remain isolated from the atmosphere;
· Developing simulation models to extrapolate the understanding of carbon sequestration processes across not only different spatial and temporal scales but also across different and potentially changing environmental conditions, such as climate change;
· Improving understanding of both possible ancillary environmental benefits and unintended impacts of enhancing carbon sequestration and the resulting economic implications; and
· Developing accurate, reliable, non-invasive methods for rapid measurement of carbon sequestration in terrestrial vegetation and soils.

A third area of sequestration research supported by the Office of Science is ocean sequestration. The ocean represents a large potential sink for sequestration of anthropogenic carbon dioxide emissions. The DOE Ocean Carbon Sequestration Research program is focusing on two strategies for enhancing carbon sequestration in the ocean and their potential environmental impacts.

The first strategy is the enhancement of the net oceanic uptake from the atmosphere by fertilization of phytoplankton with micro- or macronutrients. Iron is a micronutrient that may limit primary production in parts of the world’s oceans. Field experiments have demonstrated that addition of iron leads to a phytoplankton bloom when other nutrients are not limiting. For example, in partnership with the National Science Foundation, DOE is funding the highly successful Southern Ocean Iron Fertilization Experiment, referred to as SOFeX. In this experiment, addition of iron led to a bloom of diatoms, a form of algae, that could be seen by the NASA SeaWifs satellite. This bloom is shown in the upper left figure here. While we now know that phytoplankton growth in the Southern Ocean can be stimulated by adding iron, outstanding questions remain.
The second strategy being addressed by the DOE Ocean Carbon Sequestration Research program is direct injection of a relatively pure CO2 stream to ocean depths greater than 1000 meters. Scientists supported by DOE’s Office of Science are using laboratory and small scale in situ experiments as well as numerical modeling to examine the effectiveness and potential environmental consequences of this strategy. For example, researchers at the Monterey Bay Aquarium Research Institute are conducting experiments at a depth of more than 3000 meters to determine the effects of injection of CO2 on deep-sea organisms. One such injection of a pure stream of liquid CO2 is shown in the lower left here. This project, which is jointly funded by the Office of Science and the Office of Fossil Energy, utilizes sophisticated autonomous, robotic technologies to conduct experiments at these extraordinary depths.
In another project, computational scientists at the Lawrence Livermore National Laboratory are developing and applying numerical models of ocean circulation to determine the fate of CO2 injected at 1000 meters and the impact of such an injection on ocean chemistry. Results of modeling the fate of CO2 injected at depth into the Atlantic Ocean off the coast in the southeastern U.S. is shown in the lower right figure here. The simulation showed that the injected CO2 would spread over a large area of the Atlantic but would remain in the deep ocean and isolated from the atmosphere for over a century.
The long-term effectiveness and potential environmental consequences of ocean sequestration by either sequestration strategy are unknown. These questions are major foci of our carbon sequestration research.

DOE is taking advantage of its strength in the science of genomics by sequencing the genomes of key marine phytoplankton species and a tree species involved in carbon cycling and sequestration. Thus, our program literally spans scales from the molecular to the global to understand and enhance carbon sequestration.

The Office of Science has also committed resources through the Joint Genome Institute to sequence the genome of the third plant ever to have been sequenced and the first forest tree, specifically a member of the Populus genus, the so-called Poplar tree. Populus includes fast-growing species such as aspen, black cottonwood, and hybrid poplars.
These species stand apart from previous two plant genomes that have been sequenced so far (Arabidopsis and rice) in that they are long-lived, tall in stature, and play important roles within many of the world’s terrestrial ecosystems.

Sequencing the Populus genome creates an opportunity for the biologist to explore using emerging tools of genomics, the fundamental mechanisms that control plant biochemistry, physiology, growth, and development of highly complex organisms. This includes studying how much and in what chemical forms carbon is allocated to different below and above ground tissues of this species of tree. A goal of this research is to identify genes in Populus that provide key control points for the flow of carbon in roots. Special emphasis is placed on those mechanisms that enhance the transfer of fixed carbon to roots and the preferential synthesis of chemical forms of carbon, such as lignin, that favor the slow decomposition of soil organic matter. Research on the Populus genome may enable the development of strains of trees that provide these desired characteristics for enhancing carbon sequestration.

The Joint Genome Institute has sequenced a number of microbes that are expected to contribute to strategies for carbon sequestration. The microbes are representative of a significant portion of the earth’s photosynthesis, carbon fixation, and nitrogen cycling (intimately tied to the carbon cycle). The biology we will learn from the sequencing will be useful in a variety of both terrestrial and oceanic sequestration options.

The final area of carbon sequestration research supported by the Office of Science in the advanced biology/biotechnology area is research conducted by a team of scientists at the Institute for Biological Energy Alternatives, run by Craig Venter. The Venter team is undertaking remarkable research on a combination of advanced biological challenges that will have applications in a variety of fields. Among the first applications taken up by his team is carbon sequestration.

One area of their research is in environmental sampling and analysis to determine the diversity, metabolic pathways, and enzymes present in microbial communities. This is illustrated schematically in the upper left portion of the figure. Microbes work as communities, but because up to 99 percent cannot be cultured for study in a laboratory, it is difficult to study more than a few of the species or interactions between the species. The Venter team is approaching the problem through sequencing the genomes of all of the species in a community without isolating individual species first. They have chosen to sequence the microbes in a sample of the Sargasso Sea, which was thought to be relatively sparsely populated due to its low nutrient levels. They are finding more species than predicted.

A second area of research of the Venter team is on the development of an artificial chromosome. If we find it acceptable and advantageous to modify an organism to provide a metabolic regime favorable to our objectives, such as carbon sequestration, we may want to start with the most rudimentary set of genes capable of sustaining life. We could then add the required genes that will provide the biochemical pathways of interest. The team led by Venter is starting with one of the smallest genomes currently known (mycoplasma genitalium) and minimizing it until they can go no further. This is illustrated in the lower middle portion of the figure. If that is possible, it would then be desirable to add genes that would enable the organism with the artificial chromosome to provide a desired service or product such as converting carbon dioxide to biomass and fuels.

Engineered organisms may prove useful in a variety of settings for carbon sequestration. For example, research has been undertaken to investigate whether exhaust from fossil fuel power plants containing high levels of carbon dioxide can be bubbled through ponds containing microbes that convert the carbon dioxide and sunlight to biomass. That biomass would be sequestered directly or converted to another energy source that would replace fossil fuel. A potential application of this approach involving microalgae production in ponds is illustrated in the upper right portion of the figure. Another option would be to use the enzymes produced by organisms outside the cell in applications that involve nanotechnology as well as biology. Synthetic nano-membranes may provide an anchor for these enzymes, conferring more stability, activity, and flow of substrates. The distinction between what is biological and what is nanoscience will blur over time.

As you can see, I have given you a very rapid run-through of the carbon sequestration research areas of interest within the Office of Science. As you see they are multi-disciplinary in nature, involving all aspects of the chemical and physical sciences as well as computational performance. For those of you interested in joining with us in these activities, please contact Dr. Ari Patrinos, who heads the Office of Science’s Biological and Environmental Research (BER) program.

Thank you very much.