scholarly journals Impacts of Enhanced Weathering on biomass production for negative emission technologies and soil hydrology

2019 ◽  
Author(s):  
Wagner de Oliveira Garcia ◽  
Thorben Amann ◽  
Jens Hartmann ◽  
Kristine Karstens ◽  
Alexander Popp ◽  
...  
Keyword(s):  
Biomass Production ◽  
Large Scale ◽  
Pedotransfer Functions ◽  
Soil Hydrology ◽  
Rock Powder ◽  
Available Water ◽  
Negative Emission ◽  
Plant Available Water ◽  
Negative Emission Technologies ◽  
P Supply

Abstract. Limiting global mean temperature changes to well below 2 °C likely requires a rapid and large-scale deployment of Negative Emission Technologies (NETs). Assessments so far showed a high potential for biomass based terrestrial NETs, but only few included effects of the commonly found nutrient deficient soils on biomass production. Here, we investigate the deployment of Enhanced Weathering (EW) to supply nutrients to phosphorus (P) deficient areas of Afforestation/Reforestation and naturally growing forests (AR) and bio-energy grasses (BG), besides the impacts on soil hydrology. Using stoichiometric ratios and biomass estimates from two established vegetation models, we calculated the nutrient demand of AR and BG. By comparing the inferred AR P demand to different geogenic P supply scenarios, we estimated that 3–98 Gt C of the predicted biomass accumulation cannot be realized due to insufficient soil P supply for an AR scenario considering natural N supply. An amount of 2–362 Gt basalt powder applied by EW would be needed to cover P gaps and completely sequester projected amounts of 190 Gt C during years 2006–2099. The potential carbon sequestration by EW is 0.6–97.8 Gt CO2 for the same scenario. For BG, 8 kg basalt m−2 a−1 might, on average, replenish the exported K and P by harvest. Using pedotransfer functions, we show that the impacts of basalt powder application on soil hydraulic conductivity and plant available water, for closing predicted P gaps, would depend on basalt and soil texture, but in general the impacts are marginal. We show that EW could potentially close the projected P gaps of an AR scenario, and exported nutrients by BG harvest, which would decrease or replace the use of industrial fertilizers. Besides that, EW ameliorates soil capacity to retain nutrients, soil pH, and renew soil nutrient pools. Last, EW applications could improve plant available water capacity depending on deployed amounts of rock powder – adding a new dimension to the coupling of land-based biomass NETs with EW.

scholarly journals Impacts of enhanced weathering on biomass production for negative emission technologies and soil hydrology

2020 ◽  
Vol 17 (7) ◽  
pp. 2107-2133
Author(s):  
Wagner de Oliveira Garcia ◽  
Thorben Amann ◽  
Jens Hartmann ◽  
Kristine Karstens ◽  
Alexander Popp ◽  
...  
Keyword(s):  
Carbon Sequestration ◽  
Biomass Production ◽  
Soil Hydrology ◽  
Rock Powder ◽  
Available Water ◽  
Negative Emission ◽  
Plant Available Water ◽  
Demand Scenario ◽  
Negative Emission Technologies ◽  
P Supply

Abstract. Limiting global mean temperature changes to well below 2 ∘C likely requires a rapid and large-scale deployment of negative emission technologies (NETs). Assessments so far have shown a high potential of biomass-based terrestrial NETs, but only a few assessments have included effects of the commonly found nutrient-deficient soils on biomass production. Here, we investigate the deployment of enhanced weathering (EW) to supply nutrients to areas of afforestation–reforestation and naturally growing forests (AR) and bioenergy grasses (BG) that are deficient in phosphorus (P), besides the impacts on soil hydrology. Using stoichiometric ratios and biomass estimates from two established vegetation models, we calculated the nutrient demand of AR and BG. Insufficient geogenic P supply limits C storage in biomass. For a mean P demand by AR and a low-geogenic-P-supply scenario, AR would sequester 119 Gt C in biomass; for a high-geogenic-P-supply and low-AR-P-demand scenario, 187 Gt C would be sequestered in biomass; and for a low geogenic P supply and high AR P demand, only 92 Gt C would be accumulated by biomass. An average amount of ∼150 Gt basalt powder applied for EW would be needed to close global P gaps and completely sequester projected amounts of 190 Gt C during the years 2006–2099 for the mean AR P demand scenario (2–362 Gt basalt powder for the low-AR-P-demand and for the high-AR-P-demand scenarios would be necessary, respectively). The average potential of carbon sequestration by EW until 2099 is ∼12 Gt C (∼0.2–∼27 Gt C) for the specified scenarios (excluding additional carbon sequestration via alkalinity production). For BG, 8 kg basalt m−2 a−1 might, on average, replenish the exported potassium (K) and P by harvest. Using pedotransfer functions, we show that the impacts of basalt powder application on soil hydraulic conductivity and plant-available water, to close predicted P gaps, would depend on basalt and soil texture, but in general the impacts are marginal. We show that EW could potentially close the projected P gaps of an AR scenario and nutrients exported by BG harvest, which would decrease or replace the use of industrial fertilizers. Besides that, EW ameliorates the soil's capacity to retain nutrients and soil pH and replenish soil nutrient pools. Lastly, EW application could improve plant-available-water capacity depending on deployed amounts of rock powder – adding a new dimension to the coupling of land-based biomass NETs with EW.

Public perception and acceptance of negative emission technologies – framing effects in Switzerland

2021 ◽  
Vol 167 (3-4) ◽  
Author(s):  
Ariane Wenger ◽  
Michael Stauffacher ◽  
Irina Dallo
Keyword(s):  
Moral Hazard ◽  
Public Perception ◽  
Large Scale ◽  
Online Survey ◽  
The Public ◽  
Net Zero ◽  
Negative Emission ◽  
Public Opinion Perception ◽  
Negative Emission Technologies ◽  
Technological Fix

AbstractLimiting global warming to 1.5 °C requires negative emission technologies (NETs), which remove carbon dioxide from the atmosphere and permanently store it to offset unavoidable emissions. Successful large-scale deployment of NETs depends not only on technical, biophysical, ecological, and economic factors, but also on public perception and acceptance. However, previous studies on this topic have been scarce. In 2019, Switzerland adopted a net zero greenhouse gas emissions by 2050 target, which will require the use of NETs. To examine the current Swiss public perception and acceptance of five different NETs, we conducted an online survey with Swiss citizens (N = 693). By using a between-subjects design, we investigated differences in public opinion, perception, and acceptance across three of the most used frames in the scientific literature — technological fix, moral hazard, and climate emergency. Results showed that the public perception and acceptance of NETs does not differ between the frames. The technological fix frame best reflected participants’ opinion, whereas participants perceived the moral hazard frame the least credible and the climate emergency frame the most unclear. Moreover, our findings confirm the public’s unfamiliarity with NETs. We found no strong opposition, as participants indicated a moderate acceptance and a neutral evaluation of all five NETs, with afforestation standing out as the most accepted and positively evaluated NET. We conclude that, in the future, the public debate on NETs should be intensified, and the public perception should be monitored regularly to inform the development of NETs.

scholarly journals Moral Conflicts of several “Green” terrestrial Negative Emission Technologies regarding the Human Right to Adequate Food – A Review

2019 ◽  
Vol 49 ◽  
pp. 37-45
Author(s):  
Patrick Hohlwegler
Keyword(s):  
Global Warming ◽  
Large Scale ◽  
Carbon Capture And Storage ◽  
Human Right ◽  
Intergovernmental Panel ◽  
Moral Conflicts ◽  
Management Actions ◽  
Adequate Food ◽  
Negative Emission ◽  
Negative Emission Technologies

Abstract. Several terrestrial Negative Emission Technologies (tNETs), like Bioenergy with Carbon Capture and Storage (BECCS), Afforestation/Reforestation (AR) and Enhanced Weathering (EW), rely on natural processes and could therefore be designated as “green” forms of geoengineering. However, even those “green” tNETs may lead to undesirable side effects and thereby provoke moral concerns and conflicts. In this paper, I investigated whether BECCS, AR and EW would cause moral conflicts regarding the human right to adequate food if implemented on a scale sufficient to limit global warming “to well below 2 ∘C”. Reviewing recent publications concerning BECCS, AR and EW, I found that EW would not conflict with the human right to adequate food but would likely even promote agricultural food production due to a higher nutrient provision. However, EW does not provide a feasible solution to limit global warming “to well below 2 ∘C”, since a large-scale deployment of EW would require large investments and considerable amounts of energy to grind suitable rock-material. In regard of BECCS and AR, I found that even under the optimistic Representative Concentration Pathway 2.6 (RCP2.6), as assessed by the Intergovernmental Panel on Climate Change (IPCC) in its latest assessment report from 2013, a large-scale deployment of BECCS and/or AR would cause moral conflicts regarding the human right to adequate food for present and future generations. Due to this, I advocate for more and stronger mitigation efforts in line with efficient land management actions concerning, e.g. peats and soils, designated as “natural climate solutions” (NCS) and a deployment of multiple tNETs in near future.

Recovery of forest patches in central Mongolia after fire: Which role does soil hydrology play?

2020 ◽  
Author(s):  
Florian Schneider ◽  
Michael Klinge ◽  
Jannik Brodthuhn ◽  
Daniela Sauer
Keyword(s):  
Hydraulic Conductivity ◽  
Forest Fire ◽  
Mean Annual Precipitation ◽  
Soil Hydrology ◽  
Water Conductivity ◽  
Forest Patches ◽  
Central Mongolia ◽  
Available Water ◽  
Forest Regrowth ◽  
Plant Available Water

<p>The distribution of forest patches in the foreststeppe of central Mongolia reflects the interplay of several environmental factors that together control the vegetation pattern of the landscape. Since the mean annual precipitation of this semiarid area rarely exceeds 300 mm, the existence of forest strongly depends on the hydrological properties of the system. Only north-facing slopes provide suitable conditions for the growth of larch trees (Larix sibirica Ledeb.) due to their reduced evapotranspiration. Plains and south-facing slopes are covered by open steppe.However, after disturbance of the forest patches by fire, the regrowth of larch trees does not proceed equally in all areas. During fieldworkat the northern edge of the Khangai Mountains, we identified areas that seemed to havesimilar site conditions but neverthelessshowed different regrowth of larch trees after fire, ranging from intensive regrowth to no regrowth at all.Thisobservation stimulated us to carry out a comprehensive study of soils, vegetation and landscape development in field campaigns in 2017 and 2018, followed by laboratory analyses of soil samples.Through this work, we aimed at identifying the role of soil hydrology for forest succession in this sensitive ecotone.</p><p>We described and sampled 57 soil profiles, including sites (i) under forest, (ii) under steppe, (iii) on sites with succession after forest fire, (iv) on sites without succession after forest fire. In the field, we carried out measurements of water conductivity (by use of a compact constant head permeameter). In the laboratory, we analyzed particle size distribution and carried outkfand pF measurements.</p><p>These analyses showed that the dominant grain size of the soils was sand, whereby soils with forest regrowth had slightly loamier texture than those without regrowth. We concluded that already slightly loamier texture may be important for water storage during dry periods and thus for forest regrowth.Soils with forest regrowth had higher hydraulic conductivity in the first 25 cm and lower conductivity below.Soils without forest regrowth showeda reverse depth pattern of hydraulic conductivity. We concluded that quick drainage through the upper horizons supports forest regrowth, as it reduces competition for water with grass roots in the upper part of the soil.Soils with forest regrowth hadgreater plant-available water capacity than those without regrowth. We conclude that under the given climatic conditions, storage of plant-available water is a key factor for regrowth / no regrowth of forest after disturbance.</p>

scholarly journals ESD Ideas: Photoelectrochemical carbon removal as negative emission technology

2019 ◽  
Vol 10 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Matthias M. May ◽  
Kira Rehfeld
Keyword(s):  
Global Warming ◽  
Large Scale ◽  
Energy Use ◽  
World Population ◽  
Low Carbon ◽  
Low Carbon Economy ◽  
Negative Emissions ◽  
Negative Emission ◽  
Viable Approach ◽  
Negative Emission Technologies

Abstract. The pace of the transition to a low-carbon economy – especially in the fuels sector – is not high enough to achieve the 2 ∘C target limit for global warming by only cutting emissions. Most political roadmaps to tackle global warming implicitly rely on the timely availability of mature negative emission technologies, which actively invest energy to remove CO2 from the atmosphere and store it permanently. The models used as a basis for decarbonization policies typically assume an implementation of such large-scale negative emission technologies starting around the year 2030, ramped up to cause net negative emissions in the second half of the century and balancing earlier CO2 release. On average, a contribution of −10 Gt CO2 yr−1 is expected by 2050 (Anderson and Peters, 2016). A viable approach for negative emissions should (i) rely on a scalable and sustainable source of energy (solar), (ii) result in a safely storable product, (iii) be highly efficient in terms of water and energy use, to reduce the required land area and competition with water and food demands of a growing world population, and (iv) feature large-scale feasibility and affordability.

scholarly journals Updated European Hydraulic Pedotransfer Functions with Communicated Uncertainties in the Predicted Variables (euptfv2)

2020 ◽  
Author(s):  
Brigitta Szabó ◽  
Melanie Weynants ◽  
Tobias KD Weber
Keyword(s):  
Hydraulic Conductivity ◽  
Water Content ◽  
Pedotransfer Functions ◽  
Model Parameters ◽  
Matric Potential ◽  
Prediction Uncertainty ◽  
Continental Scale ◽  
Available Water ◽  
Plant Available Water ◽  
Soil Hydraulic

Soil hydraulic properties are often derived indirectly, i.e. computed from easily available soil properties with pedotransfer functions (PTFs), when those are needed for catchment, regional or continental scale applications. When predicted soil hydraulic parameters are used for the modelling of the state and flux of water in soils, uncertainty of the computed values can provide more detailed information when drawing conclusions. The aim of this study was to update the previously published European PTFs (Tóth et al., 2015, euptf v1.4.0) by providing prediction uncertainty calculation built into the transfer functions. The new set of algorithms was derived for point predictions of soil water content at saturation (0 cm matric potential head), field capacity (both -100 and -330 cm matric potential head), wilting point (-15.000 cm matric potential head), plant available water, and saturated hydraulic conductivity, as well as the Mualem-van Genuchten model parameters of the moisture retention and hydraulic conductivity curve. The minimum set of input properties for the prediction is soil depth and sand, silt and clay content. The effect of including additional information like soil organic carbon content, bulk density, calcium carbonate content, pH and cation exchange capacity were extensively analysed. The PTFs were derived adopting the random forest method. The advantage of the new PTFs is that they i) provide information about prediction uncertainty, ii) are significantly more accurate than the euptfv1, iii) can be applied for more predictor variable combinations than the euptfv1, 32 instead of 5, and iv) are now also derived for the prediction of water content at -100 cm matric potential head and plant available water content.

scholarly journals Ideas: Photoelectrochemical carbon removal as negative emission technology

2018 ◽  
Author(s):  
Matthias M. May ◽  
Kira Rehfeld
Keyword(s):  
Global Warming ◽  
Large Scale ◽  
Energy Use ◽  
World Population ◽  
Low Carbon ◽  
Low Carbon Economy ◽  
Negative Emissions ◽  
Negative Emission ◽  
Viable Approach ◽  
Negative Emission Technologies

Abstract. The pace of the transition to a low-carbon economy – especially in the fuels sector – is not high enough to achieve the 2 °C target limit for global warming by only cutting emissions. Most political roadmaps to tackle global warming implicitly rely on the timely availability of mature negative emission technologies, which actively invest energy to remove CO2 from the atmosphere and store it permanently. The models used as a basis for decarbonisation policies typically assume an implementation of such large-scale negative emission technologies starting around the year 2030, ramped up to cause net negative emissions in the second half of the century and balancing earlier CO2 release. On average, a contribution of −10 Gt CO2/year is expected by 2050.(Anderson and Peters, 2016) A viable approach for negative emissions should (i) rely on an unlimited source of energy (solar), (ii) result in a safely storable product (e.g. liquid or solid, not gaseous), (iii) be highly efficient in terms of water and energy use, to reduce the required land area and competition with water and food demands of a growing world population and (iv) be large-scale feasibility and affordability.

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