Energy, Resources and the Environment

What to see at EGU?: Words on Wednesday – The Green River Natural Analogue as A Field Laboratory To Study the Long-term Fate of CO2 in the subsurface

ERE Matters April 8, 2015

Words on Wednesday aims at promoting interesting/fun/exciting publications on topics related to Energy, Resources and the Environment. If you would like to be featured on WoW, please send us a link of the paper, or your own post, at ERE.Matters@gmail.com.

If you are interested in today’s WoW, some of the results will be presented during the EGU in session ERE5.2 Field methods and analysis of field data for CO2 geological storage, on Thursday at 15.30h in room R8. So go check it out! 🙂

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Busch, A. Kampman, N. Hangx, S.J.T., Snippe, J., Bickle, M. Bertier, P., Chapman, H., Spiers, C.J., Pijnenburg, R.Samuelson, J. Evans, J.P., Maskell, A., Nicholl, J., Pipich, V., Di, Z., Rother, G., Schaller, M., 2014. The Green River Natural Analogue as a field laboratory to study the long-term faith of CO₂ in the subsurface. Energy Procedia 63, 2821-2830.

Abstract:

Understanding the long-term response of CO₂ injected into porous reservoirs is one of the most important aspects to demonstrate safe and permanent storage. In order to provide quantitative constraints on the long-term impacts of CO₂-charged fluids on the integrity of reservoir-caprock systems we recovered some 300m of core from a scientific drill hole through a natural CO₂ reservoir, near Green River, Utah. We obtained geomechanical, mineralogical, geochemical, petrophysical and mineralogical laboratory data along the entire length of the core and from non CO₂-charged control samples. Furthermore, we performed more detailed studies through portions of low permeability layers in direct contact with CO₂-charged layers. This was done to constrain the nature and penetration depths of CO₂-promoted fluid-mineral reaction fronts. The major reactions identified include the dissolution of diagenetic dolomite cements and hematite grain coatings, and the precipitation of ankerite and pyrite and have been used as input for geochemical 1D reactive transport modelling, to constrain the magnitude and velocity of the mineral-fluid reaction front.

In addition, we compared geomechanical data from the CO₂-exposed core and related unreacted control samples to assess the mechanical stability of reservoir and seal rocks in a CO₂ storage complex following mineral dissolution and precipitation for thousands of years. The obtained mechanical parameters were coupled to mineralogy and porosity. Key aim of this work was to better quantify the effect of long-term chemical CO₂/brine/rock interactions on the mechanical strength and elastic properties of the studied formations.

Entrada formation from surface to top Carmel Fm with CO2-charged sandstone layer, overlain by a low permeability clayey siltstone showing bleaching and CO2 reaction features. A sharp contact between bleached and unbleached is observed.

Words on Wednesday: A multi-model analysis of change in potential yield of major crops in China under climate change

ERE Matters March 4, 2015

Words on Wednesday aims at promoting interesting/fun/exciting publications on topics related to Energy, Resources and the Environment. If you would like to be featured on WoW, please send us a link of the paper, or your own post, at ERE.Matters@gmail.com.

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Yin, Y., Tang, Q., and Liu, X.: A multi-model analysis of change in potential yield of major crops in China under climate change, Earth Syst. Dynam., 6, 45-59, doi:10.5194/esd-6-45-2015, 2015

Abstract:

Climate change may affect crop growth and yield, which consequently casts a shadow of doubt over China’s food self-sufficiency efforts. In this study, we used the projections derived from four global gridded crop models (GGCropMs) to assess the effects of future climate change on the yields of the major crops (i.e., maize, rice, soybean and wheat) in China. The GGCropMs were forced with the bias-corrected climate data from five global climate models (GCMs) under Representative Concentration Pathway (RCP) 8.5, which were made available through the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP). The results show that the potential yields of the crops would decrease in the 21st century without carbon dioxide (CO₂) fertilization effect. With the CO₂ effect, the potential yields of rice and soybean would increase, while the potential yields of maize and wheat would decrease. The uncertainty in yields resulting from the GGCropMs is larger than the uncertainty derived from GCMs in the greater part of China. Climate change may benefit rice and soybean yields in high-altitude and cold regions which are not in the current main agricultural area. However, the potential yields of maize, soybean and wheat may decrease in the major food production area. Development of new agronomic management strategies may be useful for coping with climate change in the areas with a high risk of yield reduction.

The MM of the relative change in the simulated yield of maize (a), rice (b), soybean (c) and wheat (d) with the CO2 effect at the end of the 21st century (2070–2099) compared with the simulated yield in the historical period (1981–2010).

Words on Wednesday: Environmental soil quality index and indicators for a coal mining soil

ERE Matters February 25, 2015

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Masto, R. E., Sheik, S., Nehru, G., Selvi, V. A., George, J., and Ram, L. C.: Environmental soil quality index and indicators for a coal mining soil, Solid Earth Discuss., 7, 617-638, doi:10.5194/sed-7-617-2015, 2015

Abstract:

Assessment of soil quality is one of the key parameters for evaluation of environmental contamination in the mining ecosystem. To investigate the effect of coal mining on soil quality, opencast and underground mining sites were selected in the Raniganj Coafield area, India. The physical, chemical, biological parameters, heavy metals, and PAHs contents of the soils were evaluated. Soil dehydrogenase (+79%) and fluorescein (+32%) activities were significantly higher in underground mine (UGM) soil, whereas peroxidase activity (+57%) was higher in opencast mine (OCM) soil. Content of As, Be, Co, Cr, Cu, Mn, Ni, and Pb was significantly higher in OCM soil, whereas, Cd was higher in UGM. In general, the PAHs contents were higher in UGM soils probably due to the natural coal burning in these sites. The observed values for the above properties were converted into a unit less score (0–1.00) and the scores were integrated into environmental soil quality index (ESQI). In the unscreened index (ESQI-1) all the soil parameters were included and the results showed that the quality of the soil was better for UGM (0.539) than the OCM (0.511) soils. Principal component analysis was employed to derive ESQI-2 and accordingly, total PAHs, loss on ignition, bulk density, Be, Co, Cr, Ni, Pb, and microbial quotient (respiration: microbial biomass ratio) were found to be the most critical properties. The ESQI-2 was also higher for soils near UGM (+10.1%). The proposed ESQI may be employed to monitor soil quality changes due to anthropogenic interventions.

Environmental soil quality index of opencast and underground mine soils by (a)
unscreened transformations, and (b) principal component analysis based index

Words on Wednesday: Global trends in extreme precipitation – climate models versus observations

ERE Matters February 18, 2015

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Asadieh, B. and Krakauer, N. Y.: Global trends in extreme precipitation: climate models versus observations, Hydrol. Earth Syst. Sci., 19, 877-891, doi:10.5194/hess-19-877-2015, 2015

Abstract:

Precipitation events are expected to become substantially more intense under global warming, but few global comparisons of observations and climate model simulations are available to constrain predictions of future changes in precipitation extremes. We present a systematic global-scale comparison of changes in historical (1901–2010) annual-maximum daily precipitation between station observations (compiled in HadEX2) and the suite of global climate models contributing to the fifth phase of the Coupled Model Intercomparison Project (CMIP5). We use both parametric and non-parametric methods to quantify the strength of trends in extreme precipitation in observations and models, taking care to sample them spatially and temporally in comparable ways. We find that both observations and models show generally increasing trends in extreme precipitation since 1901, with the largest changes in the deep tropics. Annual-maximum daily precipitation (Rx1day) has increased faster in the observations than in most of the CMIP5 models. On a global scale, the observational annual-maximum daily precipitation has increased by an average of 5.73 mm over the last 110 years, or 8.5% in relative terms. This corresponds to an increase of 10% K⁻¹ in global warming since 1901, which is larger than the average of climate models, with 8.3% K⁻¹. The average rate of increase in extreme precipitation per K of warming in both models and observations is higher than the rate of increase in atmospheric water vapor content per K of warming expected from the Clausius–Clapeyron equation. We expect our findings to help inform assessments of precipitation-related hazards such as flooding, droughts and storms.

HadEX2 observational data versus CMIP5 averaged results of global extreme precipitation in 1901–2010 – annual-maximum daily precipitation map (mm day-1) for (a) HadEX2 and (b) the average of CMIP5 model runs.