| 31. |
- Eltigani, Amna, et al.
(författare)
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Exploring lessons from five years of biochar-producing cookstoves in the Kagera region, Tanzania
- 2022
-
Ingår i: Energy for Sustainable Development. - : Elsevier BV. - 0973-0826 .- 2352-4669. ; 71, s. 141-150
-
Tidskriftsartikel (refereegranskat)abstract
- Biochar-producing cookstoves can supply fuel-efficient heat for cooking in developing countries. The produced biochar can be used as a soil amendment, providing a range of environmental and agronomic benefits and serve to remove carbon dioxide from the atmosphere. Despite these advantages, many stove initiatives have not been sustained in the long term, but very little attention has been devoted to understanding the reasons be-hind this. The present study contributes to filling this knowledge gap, by identifying key factors affecting the level of stove adoption and use, as well as biochar utilization. Based on a follow-up survey of 50 households in north-western Tanzania that received microgasifier stoves in 2015, only 12 still made use of their stove 5 years later. One of the main reasons for this relates to the inadequate quality of stove material. Declining or inconsistent availability of feedstocks was also identified as a major challenge. Furthermore, the households generally did not embrace the idea of amending soils with biochar, due to a combination of local practices and perceptions, and a lack of education and awareness programs. We conclude that, under the conditions of the studied project, three factors are required to scale dissemination: improvement of the stove design, provision of training pro-grams on biochar management and subsidies or microloans that would make more durable stoves affordable. Sustained stove deployment can only be achievable by institutionalizing financing structures that are indepen-dent from short-term grant-based initiatives.
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| 32. |
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| 33. |
- Ernest, Baraka, et al.
(författare)
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Evaluation of selected organic fertilizers on conditioning soil health of smallholder households in Karagwe, Northwestern Tanzania
- 2024
-
Ingår i: Heliyon. - : Elsevier. - 2405-8440. ; 10:4
-
Tidskriftsartikel (refereegranskat)abstract
- Soil management is a strategy for improving soil suffering from problems such as low pH, nutrient deficiency, and erosion. The study evaluated the effects of human urine (HU), biogas slurry (BS), standard compost (StC), animal manure (AM), and synthetic fertilizer (SF) in comparison with no soil fertility management (NFM) on soil pH, cation exchange capacity (CEC), soil organic carbon (SOC), soil moisture content, nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), copper (Cu), zinc (Zn), manganese (Mn), and iron (Fe) in the Karagwe district, a Northwestern Tanzania. Four household farms representing each soil amendment type were selected for soil sampling. A total of 192 soil samples were collected and air-dried. After laboratory analysis, BS-enriched soil had the highest pH (6.558), CEC (23.945 cmol+/kg), SOC (5.573%), soil moisture (5.573%), N (0.497%), P (247.130 mg/kg), K (3.036 cmol+/kg), Ca (18.983 cmol+/kg), Mg (4.076 cmol+/kg), Na (2.960 cmol+/kg), and Cu (12.548 mg/kg). Similar soil properties were lower in NFM than in the other soils. The soil properties on the chosen farms did not differ significantly depending on the sampling zone for each organic fertilizer. Therefore, the result indicates that all evaluated organic fertilizers improved soil health compared to NFM, but BS and HU fertilizers led to relatively better soil health improvements than StC, AM, and SF.
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| 34. |
- Forsling, Robin, 1988-, et al.
(författare)
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Conservative Linear Unbiased Estimation Under Partially Known Covariances
- 2022
-
Ingår i: IEEE Transactions on Signal Processing. - : IEEE. - 1053-587X .- 1941-0476. ; 70, s. 3123-3135
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Tidskriftsartikel (refereegranskat)abstract
- Mean square error optimal estimation requires the full correlation structure to be available. Unfortunately, it is not always possible to maintain full knowledge about the correlations. One example is decentralized data fusion where the cross-correlations between estimates are unknown, partly due to information sharing. To avoid underestimating the covariance of an estimate in such situations, conservative estimation is one option. In this paper the conservative linear unbiased estimator is formalized including optimality criteria. Fundamental bounds of the optimal conservative linear unbiased estimator are derived. A main contribution is a general approach for computing the proposed estimator based on robust optimization. Furthermore, it is shown that several existing estimation algorithms are special cases of the optimal conservative linear unbiased estimator. An evaluation verifies the theoretical considerations and shows that the optimization based approach performs better than existing conservative estimation methods in certain cases.
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| 35. |
- Fridahl, Mathias, 1980-, et al.
(författare)
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Biochar deployment drivers and barriers in least developed countries
- 2021
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Ingår i: Handbook of climate change management. - Cham : Springer. - 9783030227593 ; , s. 1-30
-
Bokkapitel (refereegranskat)abstract
- Agriculture in the least developed countries (LDCs) is highly vulnerable to the impacts of climate change. Applying biochar to soils has been proposed as a solution, especially in the carbon-depleted and acid sub-Saharan soils. Correctly applied, biochar increases yield capacities, decreases contamination, and promotes resilience. Hope is that biochar will store atmospheric carbon in soils, thus generating negative emissions. Nonetheless, several goal conflicts may arise, for example, between the global aspirations to achieve negative carbon emissions and local sustainability. Using interviews, a survey, and field visits to biochar initiatives in Tanzania, this chapter explores deployment drivers and barriers in LDCs and their implications for biochar carbon removal in local contexts. As such, it seeks to address a gap in the literature on actual, opposed to hypothesized, engagement of biochar practitioners. The chapter concludes that the idea of carbon removal alone is unlikely to motivate widespread biochar deployment in LDCs. Optimization of carbon content and stability must be balanced against maximizing yields with minimum inputs. Tangible results drive deployment among smallholders and agricultural businesses alike, yet developing biochar systems is challenging due to their complexity and long lead times. Thus, while financing and external expertise are vital at the initial stages, education, wareness, and persistent demonstration are key to sustained action.
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| 36. |
- Fridahl, Mathias, 1980-, et al.
(författare)
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Mapping Multi-Level Policy Incentives for Bioenergy With Carbon Capture and Storage in Sweden
- 2020
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Ingår i: Frontiers in Climate. - : Frontiers Media S.A.. - 2624-9553. ; 2, s. 1-25
-
Tidskriftsartikel (refereegranskat)abstract
- Bioenergy with carbon capture and storage (BECCS) is considered a key mitigation technology in most 1.5–2.0°C compatible climate change mitigation scenarios. Nonetheless, examples of BECCS deployment are lacking internationally. It is widely acknowledged that widespread implementation of this technology requires strong policy enablers, and that such enablers are currently non-existent. However, the literature lacks a more structured assessment of the “incentive gap” between scenarios with substantive BECCS deployment and existing policy enablers to effectuate BECCS deployment. Sweden, a country with progressive climate policies and particularly good preconditions for BECCS, constitutes a relevant locus for such examinations. The paper asks to what extent and how existing UN, EU, and Swedish climate policy instruments incentivize BECCS research, development, demonstration, and deployment in Sweden. The analysis is followed by a tentative discussion of needs for policy reform to improve the effectiveness of climate policy in delivering BECCS. Drawing on a tripartite typology of policy instruments (economic, regulatory, and informational) and the ability of these instruments to create supply-push or demand-pull, the article finds that: (1) no instruments create a demand-pull to cover operational expenditure; (2) economic instruments provide partial support for research and the capital expenditure associated with demonstration, and; (3) regulatory instruments provide partial clarity on environmental safeguards and responsibilities. A few regulatory barriers also continue to counteract deployment. The article concludes that the existing policy mix requires considerable reform if BECCS is to contribute substantially to the Swedish target for net-zero emissions. Continued effort to dismantle regulatory barriers must be complemented with a strong demand-pull instrument that complements the current focus on supply-push incentives. If unreformed, the existing policy mix will most likely lead to substantial public expenditure on BECCS research, development, and demonstration without leading to any substantial deployment and diffusion.
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| 37. |
- Fridahl, Mathias, 1980-, et al.
(författare)
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Novel carbon dioxide removals techniques must be integrated into the European Union’s climate policies
- 2023
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Ingår i: Communications Earth & Environment. - Stockholm : Springer Nature. - 2662-4435. ; 4:1
-
Tidskriftsartikel (refereegranskat)abstract
- Emissions reductions are crucial to mitigating climate change. However, in the past decade, the world community’s failure to reduce emissions at a sufficient speed to avoid dangerous climate change has become obvious4. This reality acutely necessitates the development of innovative sets of policies to spur the deployment of novel CO2 removals, an urgency that is further underlined by the long lead time for many novel removal methods. Disregarding the potential of novel removals is incommensurate with the scale of the challenge of achieving EU’s commitment to reach net-zero greenhouse gas emissions by 2050.We argue that the current policy framework neither provides Union-wide economic incentives for novel CO2 removals, nor does it encourage EU Member States to develop national policy incentives. Our proposed solutions includes incentivizing removals through a conditional integration into the EU Emissions Trading System (ETS), expanding the portfolio of removal methods in the Land-Use, Land-Use Change and Forestry (LULUCF) Regulation, and to manage anticipations regarding which residual emissions that need to be counterbalanced by removals.
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| 38. |
- Fridahl, Mathias, 1980-, et al.
(författare)
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Towards Indicators for a Negative Emissions Climate Stabilisation Index : Problems and Prospects
- 2020
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Ingår i: Climate. - : BioMed Central. - 2225-1154. ; 8:6
-
Forskningsöversikt (refereegranskat)abstract
- The incongruence between the United Nations objective to hold global warming well below 2 °C and the rate of global emission reductions has intensified interest in negative emissions. Previous research has explored several pros and cons of individual negative emissions technologies. Systematised approaches to comparing and prioritising among them are, however, largely lacking. In response to this gap in the literature, this article reviews the scientific literature on indicators for designing negative emissions climate stabilisation value indexes. An index typically provides summary measures of several components, often denoted indicators. Utilizing a narrative review methodology, the article derives five categories of indicators underpinned by overlapping and often mutually reinforcing environmental and socio-economic values. A list of 21 indicators are proposed to capture both positive and negative values associated with effectiveness, efficiency, scale, risk, and synergies. While discussing indicators capable of providing guidance on negative emissions is timely, given the emerging shift away from pure emission reduction targets towards net-zero targets, numerous complexities are involved in determining their relative values. The results herein serve to inform policy making on the prioritisation and incentivisation of negative emissions technologies capable of delivering on the new objectives, and the results highlight the many risks and uncertainties involved in such exercises. The article concludes that systematic research on the comparison of NETs is incomplete. An iterative, interdisciplinary research programme exploring such questions has the potential to be extremely rewarding
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| 39. |
- Gourdon, Pontus Emanuel, 1978, et al.
(författare)
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Optimized in vitro and in vivo expression of proteorhodopsin: A seven-transmembrane proton pump
- 2008
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Ingår i: Protein Expression and Purification. - : Elsevier BV. - 1096-0279 .- 1046-5928. ; 58:1, s. 103-113
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Tidskriftsartikel (refereegranskat)abstract
- Proteorhodopsin is an integral membrane light-harvesting proton pump that is found in bacteria distributed throughout global surface waters. Here, we present a protocol for functional in vitro production of pR using a commercial cell-free synthesis system yielding 1.0 mg purified protein per milliliter of cell lysate. We also present an optimized protocol for in vivo over-expression of pR in Escherichia coli, and a two-step purification yielding 5 mg of essentially pure functional protein per liter of culture. Both approaches are straightforward, rapid, and easily scalable. Thus either may facilitate the exploitation of pR for commercial biotechnological applications. Finally, the implications of some observations of the in vitro synthesis behavior, as well as preliminary results towards a structural determination of pR are discussed.
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| 40. |
- Haikola, Simon, 1982-, et al.
(författare)
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From polarization to reluctant acceptance : Bioenergy with carbon capture and storage (BECCS) and the post-normalization of the climate debate
- 2019
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Ingår i: Journal of Integrative Environmental Sciences. - : Taylor & Francis. - 1943-815X .- 1943-8168. ; 16:1, s. 45-69
-
Tidskriftsartikel (refereegranskat)abstract
- The paper covers the public debate on BECCS (bioenergy with carbon capture and storage) between 2008 and 2018. Through a qualitative analysis of around 800 feature articles, editorials, and opinion pieces published in English, German, Swedish, Danish, and Norwegian in news media and debates sections of scientific media, we highlight conspicuous aspects of the debate and relate them to the theoretical concept of post-normal science. We find that the debate is characterized by an emphasis on values, scientific uncertainty and the integrity of science, premised on a pervading sense of urgency. To a significant extent, the debate can be understood as a “normal” view of science questioning what it perceives to be unscientific model-based climate scenarios, and the scenarios, in turn, can be seen as a response to post-normal circumstances. The urgency permeating the debate provides conditions for open debate about ethical and epistemological uncertainty. The debate goes through a period of polarization – corroborating findings from previous studies on the climate science debate after COP21 – between an intense critique of BECCS inclusion in climate scenarios and reluctant acceptance thereof. Towards the end of the studied period, emphasis shifts towards reluctant acceptance, indicating that post-normal debate may only occur as a temporary state always tending towards new consensus.
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