cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.1011634
title: The ratio of Rh over Rs from SRDB-V2

description: <b>Table 1.</b> The ratio of Rh over Rs from SRDB-V2. (Note: <em>N</em>-Obs and <em>N</em> are the plots with the definite partitioning methods and plots with both Rh and Rs values, respectively. Methods used to partition Ra and Rh by studies in the SRDB-V2 database (described in [21] and references therein) included 'comparison' (comparing fluxes from nearby locations with and without roots), 'equation' (scaling tissue specific rates using biomass measurements), 'exclusion' (digging trenches around plots to exclude roots), 'extraction' (measuring efflux from roots and soil separate from each other), 'isotope' (stable or radioactive isotope labeling; exploiting or manipulating differences in isotopic signature of roots and bulk soil), 'regression' (calculating Ra from a regression of Rs and root biomass dynamics) and 'mass balance' (subtracting measurements of other respiration components).) <strong>Abstract</strong> Soil microbial respiration (Rh) is a large but uncertain component of the terrestrial carbon cycle. Carbon–climate feedbacks associated with changes to Rh are likely, but Rh parameterization in Earth System Models (ESMs) has not been rigorously evaluated largely due to a lack of appropriate measurements. Here we assess, for the first time, Rh estimates from eight ESMs and their environmental drivers across several biomes against a comprehensive soil respiration database (SRDB-V2). Climatic, vegetation, and edaphic factors exert strong controls on annual Rh in ESMs, but these simple controls are not as apparent in the observations. This raises questions regarding the robustness of ESM projections of Rh in response to future climate change. Since there are many more soil respiration (Rs) observations than Rh data, two 'reality checks' for ESMs are also created using the Rs data. Guidance is also provided on the Rh improvement in ESMs.
DOI: 10.6084/m9.figshare.1011635.v1
title: The statistics of the annual Rh (g C m<sup>−2</sup>) based on the partial least squares (PLS) regression

description: <b>Table 2.</b> The statistics of the annual Rh (g C m<sup>−2</sup>) based on the partial least squares (PLS) regression. (Note: covariates for the prediction of ln(Rh) include the annual mean surface temperature (<em>T</em>, ° C), and the logarithms of annual precipitation (Pr, mm), net primary production (NPP, g C m<sup>−2</sup>), and soil organic carbon (SOC, g Cm<sup>−2</sup>). The <em>r</em><sup>2</sup> and RMSE values are the coefficient of determination and root mean square error between Rh and fitted values, respectively.) <strong>Abstract</strong> Soil microbial respiration (Rh) is a large but uncertain component of the terrestrial carbon cycle. Carbon–climate feedbacks associated with changes to Rh are likely, but Rh parameterization in Earth System Models (ESMs) has not been rigorously evaluated largely due to a lack of appropriate measurements. Here we assess, for the first time, Rh estimates from eight ESMs and their environmental drivers across several biomes against a comprehensive soil respiration database (SRDB-V2). Climatic, vegetation, and edaphic factors exert strong controls on annual Rh in ESMs, but these simple controls are not as apparent in the observations. This raises questions regarding the robustness of ESM projections of Rh in response to future climate change. Since there are many more soil respiration (Rs) observations than Rh data, two 'reality checks' for ESMs are also created using the Rs data. Guidance is also provided on the Rh improvement in ESMs.
DOI: 10.6084/m9.figshare.1011634.v1
title: The ratio of Rh over Rs from SRDB-V2

description: <b>Table 1.</b> The ratio of Rh over Rs from SRDB-V2. (Note: <em>N</em>-Obs and <em>N</em> are the plots with the definite partitioning methods and plots with both Rh and Rs values, respectively. Methods used to partition Ra and Rh by studies in the SRDB-V2 database (described in [21] and references therein) included 'comparison' (comparing fluxes from nearby locations with and without roots), 'equation' (scaling tissue specific rates using biomass measurements), 'exclusion' (digging trenches around plots to exclude roots), 'extraction' (measuring efflux from roots and soil separate from each other), 'isotope' (stable or radioactive isotope labeling; exploiting or manipulating differences in isotopic signature of roots and bulk soil), 'regression' (calculating Ra from a regression of Rs and root biomass dynamics) and 'mass balance' (subtracting measurements of other respiration components).) <strong>Abstract</strong> Soil microbial respiration (Rh) is a large but uncertain component of the terrestrial carbon cycle. Carbon–climate feedbacks associated with changes to Rh are likely, but Rh parameterization in Earth System Models (ESMs) has not been rigorously evaluated largely due to a lack of appropriate measurements. Here we assess, for the first time, Rh estimates from eight ESMs and their environmental drivers across several biomes against a comprehensive soil respiration database (SRDB-V2). Climatic, vegetation, and edaphic factors exert strong controls on annual Rh in ESMs, but these simple controls are not as apparent in the observations. This raises questions regarding the robustness of ESM projections of Rh in response to future climate change. Since there are many more soil respiration (Rs) observations than Rh data, two 'reality checks' for ESMs are also created using the Rs data. Guidance is also provided on the Rh improvement in ESMs.
DOI: 10.6084/m9.figshare.1011624
title: Continental and global effects of different Δ<em>T</em><sub>g</sub> levels

description: <b>Table 1.</b> Continental and global effects of different Δ<em>T</em><sub>g</sub> levels. Top: millions of people living in river basins characterized by chronic water scarcity (&lt;1000 m<sup>3</sup> cap<sup>−1</sup> yr<sup>−1</sup>) (cases (2) and (4)), either with or without B1 and A2r future population change. People in water-scarce basins that show an aggravation of scarcity according to case (1) (see figure 3(a)) are not counted here. Numbers in brackets denote the changes (relative to the present) that are solely due to climate change. Bottom: number of unique biogeographic regions (out of 90) exposed to severe biogeochemical or vegetation structural shifts. All values refer to changes with &gt;50% confidence, simulated under at least 10 of the 19 GCM patterns. <strong>Abstract</strong> This modelling study demonstrates at what level of global mean temperature rise (Δ<em>T</em><sub>g</sub>) regions will be exposed to significant decreases of freshwater availability and changes to terrestrial ecosystems. Projections are based on a new, consistent set of 152 climate scenarios (eight Δ<em>T</em><sub>g</sub> trajectories reaching 1.5–5 ° C above pre-industrial levels by 2100, each scaled with spatial patterns from 19 general circulation models). The results suggest that already at a Δ<em>T</em><sub>g</sub> of 2 ° C and mainly in the subtropics, higher water scarcity would occur in &gt;50% out of the 19 climate scenarios. Substantial biogeochemical and vegetation structural changes would also occur at 2 ° C, but mainly in subpolar and semiarid ecosystems. Other regions would be affected at higher Δ<em>T</em><sub>g</sub> levels, with lower intensity or with lower confidence. In total, mean global warming levels of 2 ° C, 3.5 ° C and 5 ° C are simulated to expose an additional 8%, 11% and 13% of the world population to new or aggravated water scarcity, respectively, with &gt;50% confidence (while ~1.3 billion people already live in water-scarce regions). Concurrently, substantial habitat transformations would occur in biogeographic regions that contain 1% (in zones affected at 2 ° C), 10% (3.5 ° C) and 74% (5 ° C) of present endemism-weighted vascular plant species, respectively. The results suggest nonlinear growth of impacts along with Δ<em>T</em><sub>g</sub> and highlight regional disparities in impact magnitudes and critical Δ<em>T</em><sub>g</sub> levels.
DOI: 10.6084/m9.figshare.1011612
title: Cash flow results for the pipeline capital and operation

description: <b>Table 6.</b> Cash flow results for the pipeline capital and operation. Values in millions $2009. <strong>Abstract</strong> This letter compares several bounding cases for understanding the economic viability of capturing large quantities of anthropogenic CO<sub>2</sub> from coal-fired power generators within the Electric Reliability Council of Texas electric grid and using it for pure CO<sub>2</sub> enhanced oil recovery (EOR) in the onshore coastal region of Texas along the Gulf of Mexico. All captured CO<sub>2</sub> in excess of that needed for EOR is sequestered in saline formations at the same geographic locations as the oil reservoirs but at a different depth. We analyze the extraction of oil from the same set of ten reservoirs within 20- and five-year time frames to describe how the scale of the carbon dioxide capture, utilization, and storage (CCUS) network changes to meet the rate of CO<sub>2</sub> demand for oil recovery. Our analysis shows that there is a negative system-wide net present value (NPV) for all modeled scenarios. The system comes close to breakeven economics when capturing CO<sub>2</sub> from three coal-fired power plants to produce oil via CO<sub>2</sub>-EOR over 20 years and assuming no CO<sub>2</sub> emissions penalty. The NPV drops when we consider a larger network to produce oil more quickly (21 coal-fired generators with CO<sub>2</sub> capture to produce 80% of the oil within five years). Upon applying a CO<sub>2</sub> emissions penalty of 60$2009/tCO<sub>2</sub> to fossil fuel emissions to ensure that coal-fired power plants with CO<sub>2</sub> capture remain in baseload operation, the system economics drop significantly. We show near profitability for the cash flow of the EOR operations only; however, this situation requires relatively cheap electricity prices during operation.
DOI: 10.6084/m9.figshare.1011613
title: Cash flow results for the EOR and saline sequestration components of the CCUS network

description: <b>Table 7.</b> Cash flow results for the EOR and saline sequestration components of the CCUS network. Values in millions $2009. If three values are present for each scenario, these represent results assuming the three electricity prices (0.05$ kWh<sup>−1</sup>, industrial, and residential). <strong>Abstract</strong> This letter compares several bounding cases for understanding the economic viability of capturing large quantities of anthropogenic CO<sub>2</sub> from coal-fired power generators within the Electric Reliability Council of Texas electric grid and using it for pure CO<sub>2</sub> enhanced oil recovery (EOR) in the onshore coastal region of Texas along the Gulf of Mexico. All captured CO<sub>2</sub> in excess of that needed for EOR is sequestered in saline formations at the same geographic locations as the oil reservoirs but at a different depth. We analyze the extraction of oil from the same set of ten reservoirs within 20- and five-year time frames to describe how the scale of the carbon dioxide capture, utilization, and storage (CCUS) network changes to meet the rate of CO<sub>2</sub> demand for oil recovery. Our analysis shows that there is a negative system-wide net present value (NPV) for all modeled scenarios. The system comes close to breakeven economics when capturing CO<sub>2</sub> from three coal-fired power plants to produce oil via CO<sub>2</sub>-EOR over 20 years and assuming no CO<sub>2</sub> emissions penalty. The NPV drops when we consider a larger network to produce oil more quickly (21 coal-fired generators with CO<sub>2</sub> capture to produce 80% of the oil within five years). Upon applying a CO<sub>2</sub> emissions penalty of 60$2009/tCO<sub>2</sub> to fossil fuel emissions to ensure that coal-fired power plants with CO<sub>2</sub> capture remain in baseload operation, the system economics drop significantly. We show near profitability for the cash flow of the EOR operations only; however, this situation requires relatively cheap electricity prices during operation.
DOI: 10.6084/m9.figshare.1011611
title: Cash flow results for the CO<sub>2</sub> capture capital and operation (independent of the capital and operation for electricity generation as we consider only the additional costs and revenues for CO<sub>2</sub> capture)

description: <b>Table 5.</b> Cash flow results for the CO<sub>2</sub> capture capital and operation (independent of the capital and operation for electricity generation as we consider only the additional costs and revenues for CO<sub>2</sub> capture). Values in millions $2009. <strong>Abstract</strong> This letter compares several bounding cases for understanding the economic viability of capturing large quantities of anthropogenic CO<sub>2</sub> from coal-fired power generators within the Electric Reliability Council of Texas electric grid and using it for pure CO<sub>2</sub> enhanced oil recovery (EOR) in the onshore coastal region of Texas along the Gulf of Mexico. All captured CO<sub>2</sub> in excess of that needed for EOR is sequestered in saline formations at the same geographic locations as the oil reservoirs but at a different depth. We analyze the extraction of oil from the same set of ten reservoirs within 20- and five-year time frames to describe how the scale of the carbon dioxide capture, utilization, and storage (CCUS) network changes to meet the rate of CO<sub>2</sub> demand for oil recovery. Our analysis shows that there is a negative system-wide net present value (NPV) for all modeled scenarios. The system comes close to breakeven economics when capturing CO<sub>2</sub> from three coal-fired power plants to produce oil via CO<sub>2</sub>-EOR over 20 years and assuming no CO<sub>2</sub> emissions penalty. The NPV drops when we consider a larger network to produce oil more quickly (21 coal-fired generators with CO<sub>2</sub> capture to produce 80% of the oil within five years). Upon applying a CO<sub>2</sub> emissions penalty of 60$2009/tCO<sub>2</sub> to fossil fuel emissions to ensure that coal-fired power plants with CO<sub>2</sub> capture remain in baseload operation, the system economics drop significantly. We show near profitability for the cash flow of the EOR operations only; however, this situation requires relatively cheap electricity prices during operation.
DOI: 10.6084/m9.figshare.1011612.v1
title: Cash flow results for the pipeline capital and operation

description: <b>Table 6.</b> Cash flow results for the pipeline capital and operation. Values in millions $2009. <strong>Abstract</strong> This letter compares several bounding cases for understanding the economic viability of capturing large quantities of anthropogenic CO<sub>2</sub> from coal-fired power generators within the Electric Reliability Council of Texas electric grid and using it for pure CO<sub>2</sub> enhanced oil recovery (EOR) in the onshore coastal region of Texas along the Gulf of Mexico. All captured CO<sub>2</sub> in excess of that needed for EOR is sequestered in saline formations at the same geographic locations as the oil reservoirs but at a different depth. We analyze the extraction of oil from the same set of ten reservoirs within 20- and five-year time frames to describe how the scale of the carbon dioxide capture, utilization, and storage (CCUS) network changes to meet the rate of CO<sub>2</sub> demand for oil recovery. Our analysis shows that there is a negative system-wide net present value (NPV) for all modeled scenarios. The system comes close to breakeven economics when capturing CO<sub>2</sub> from three coal-fired power plants to produce oil via CO<sub>2</sub>-EOR over 20 years and assuming no CO<sub>2</sub> emissions penalty. The NPV drops when we consider a larger network to produce oil more quickly (21 coal-fired generators with CO<sub>2</sub> capture to produce 80% of the oil within five years). Upon applying a CO<sub>2</sub> emissions penalty of 60$2009/tCO<sub>2</sub> to fossil fuel emissions to ensure that coal-fired power plants with CO<sub>2</sub> capture remain in baseload operation, the system economics drop significantly. We show near profitability for the cash flow of the EOR operations only; however, this situation requires relatively cheap electricity prices during operation.
DOI: 10.6084/m9.figshare.1011613.v1
title: Cash flow results for the EOR and saline sequestration components of the CCUS network

description: <b>Table 7.</b> Cash flow results for the EOR and saline sequestration components of the CCUS network. Values in millions $2009. If three values are present for each scenario, these represent results assuming the three electricity prices (0.05$ kWh<sup>−1</sup>, industrial, and residential). <strong>Abstract</strong> This letter compares several bounding cases for understanding the economic viability of capturing large quantities of anthropogenic CO<sub>2</sub> from coal-fired power generators within the Electric Reliability Council of Texas electric grid and using it for pure CO<sub>2</sub> enhanced oil recovery (EOR) in the onshore coastal region of Texas along the Gulf of Mexico. All captured CO<sub>2</sub> in excess of that needed for EOR is sequestered in saline formations at the same geographic locations as the oil reservoirs but at a different depth. We analyze the extraction of oil from the same set of ten reservoirs within 20- and five-year time frames to describe how the scale of the carbon dioxide capture, utilization, and storage (CCUS) network changes to meet the rate of CO<sub>2</sub> demand for oil recovery. Our analysis shows that there is a negative system-wide net present value (NPV) for all modeled scenarios. The system comes close to breakeven economics when capturing CO<sub>2</sub> from three coal-fired power plants to produce oil via CO<sub>2</sub>-EOR over 20 years and assuming no CO<sub>2</sub> emissions penalty. The NPV drops when we consider a larger network to produce oil more quickly (21 coal-fired generators with CO<sub>2</sub> capture to produce 80% of the oil within five years). Upon applying a CO<sub>2</sub> emissions penalty of 60$2009/tCO<sub>2</sub> to fossil fuel emissions to ensure that coal-fired power plants with CO<sub>2</sub> capture remain in baseload operation, the system economics drop significantly. We show near profitability for the cash flow of the EOR operations only; however, this situation requires relatively cheap electricity prices during operation.
DOI: 10.6084/m9.figshare.1011610
title: Summary of system-wide economics of CCUS network ($2009 million)

description: <b>Table 4.</b> Summary of system-wide economics of CCUS network ($2009 million). A 10% discount rates is used for NPV analysis. Three values for a given scenario represent the three different electricity prices assumed for sensitivity analysis (from top to bottom, 0.05$ kWh<sup>−1</sup>; industrial; residential). <strong>Abstract</strong> This letter compares several bounding cases for understanding the economic viability of capturing large quantities of anthropogenic CO<sub>2</sub> from coal-fired power generators within the Electric Reliability Council of Texas electric grid and using it for pure CO<sub>2</sub> enhanced oil recovery (EOR) in the onshore coastal region of Texas along the Gulf of Mexico. All captured CO<sub>2</sub> in excess of that needed for EOR is sequestered in saline formations at the same geographic locations as the oil reservoirs but at a different depth. We analyze the extraction of oil from the same set of ten reservoirs within 20- and five-year time frames to describe how the scale of the carbon dioxide capture, utilization, and storage (CCUS) network changes to meet the rate of CO<sub>2</sub> demand for oil recovery. Our analysis shows that there is a negative system-wide net present value (NPV) for all modeled scenarios. The system comes close to breakeven economics when capturing CO<sub>2</sub> from three coal-fired power plants to produce oil via CO<sub>2</sub>-EOR over 20 years and assuming no CO<sub>2</sub> emissions penalty. The NPV drops when we consider a larger network to produce oil more quickly (21 coal-fired generators with CO<sub>2</sub> capture to produce 80% of the oil within five years). Upon applying a CO<sub>2</sub> emissions penalty of 60$2009/tCO<sub>2</sub> to fossil fuel emissions to ensure that coal-fired power plants with CO<sub>2</sub> capture remain in baseload operation, the system economics drop significantly. We show near profitability for the cash flow of the EOR operations only; however, this situation requires relatively cheap electricity prices during operation.
DOI: 10.6084/m9.figshare.1011608
title: Capital and operating expenditures for each of the ten CO<sub>2</sub>-EOR fields analyzed for the Texas Gulf Coast in $/BBL

description: <b>Table 2.</b> Capital and operating expenditures for each of the ten CO<sub>2</sub>-EOR fields analyzed for the Texas Gulf Coast in $/BBL. We assumed that EOR injection and production wells are drilled by side-tracking existing wells, so that capital costs are assumed at 50% of the cost of a new well. <strong>Abstract</strong> This letter compares several bounding cases for understanding the economic viability of capturing large quantities of anthropogenic CO<sub>2</sub> from coal-fired power generators within the Electric Reliability Council of Texas electric grid and using it for pure CO<sub>2</sub> enhanced oil recovery (EOR) in the onshore coastal region of Texas along the Gulf of Mexico. All captured CO<sub>2</sub> in excess of that needed for EOR is sequestered in saline formations at the same geographic locations as the oil reservoirs but at a different depth. We analyze the extraction of oil from the same set of ten reservoirs within 20- and five-year time frames to describe how the scale of the carbon dioxide capture, utilization, and storage (CCUS) network changes to meet the rate of CO<sub>2</sub> demand for oil recovery. Our analysis shows that there is a negative system-wide net present value (NPV) for all modeled scenarios. The system comes close to breakeven economics when capturing CO<sub>2</sub> from three coal-fired power plants to produce oil via CO<sub>2</sub>-EOR over 20 years and assuming no CO<sub>2</sub> emissions penalty. The NPV drops when we consider a larger network to produce oil more quickly (21 coal-fired generators with CO<sub>2</sub> capture to produce 80% of the oil within five years). Upon applying a CO<sub>2</sub> emissions penalty of 60$2009/tCO<sub>2</sub> to fossil fuel emissions to ensure that coal-fired power plants with CO<sub>2</sub> capture remain in baseload operation, the system economics drop significantly. We show near profitability for the cash flow of the EOR operations only; however, this situation requires relatively cheap electricity prices during operation.