29 research outputs found
Engineering soils to act as carbon sinks
PhD ThesisSoils containing calcium (Ca) and magnesium (Mg) bearing waste silicate minerals may
be intentionally engineered to capture and store atmospheric carbon (C). Within the soil
environment these minerals can capture and store atmospheric C through the process of
weathering that releases Ca and Mg which then precipitate as carbonate minerals. Like
natural silicates, silicate âwastesâ and artificial silicates sequester C through carbonation
of calcium (Ca2+) and magnesium (Mg2+). Terrestrial CO2 sequestration may be
promoted by the inclusion of these reactive mineral substrates in soils, and many waste
sites and urban and anthropogenic soils already contain quantities of these materials.
The UK Government is currently committed to reducing carbon emissions by 80% in
2050 (against a 1990 baseline) and soils have a role to play, acting as sinks for carbon.
It is proposed that soil engineering measures could harness the high C turnover of the
global pedologic system, ~120Pg C a-1 , to develop an efficient method of enhanced
weathering. Artificial silicates have the potential to capture 192-333 Mt C a-1 ,
representing 2.0-3.7% of contemporary global C emissions; natural silicates present a
carbon capture potential many orders of magnitude greater. Mineral carbonation in an
artificial soil setting has the potential to capture inorganic carbon comparable to organic
carbon accumulation. Soils of this type can accumulate 20-30 kg C m2 as carbonates (â„
organic carbon content in natural soils, ~17.5 kg C m2 for rural soils in the UK).
Laboratory investigations were carried out on a number of experimental scales, from
meso-scale flow-through reactors to micro-scale batch experiments, to determine the
rate at which Ca and Mg could be supplied from suitable materials in engineered soil
systems to perform a carbon capture function. Environmental factors were controlled for
each in order to constrain their contribution to the overall process. Batch experiments
were carried out at standard temperature and pressure (STP) to investigate effects of
changes in solute concentration, water chemistry, agitation and particle size. pH
controlled experiments were run at STP from pH 3-8, to determine the effects of pH
changes on the weathering of wollastonite. Flow-through weathering experiments at
STP investigated the effects of time, water chemistry, hydrogeological conditions and
addition of CO2 on the weathering of steel slag. Analytical results demonstrate that Ca
leaches rapidly from a number of Ca-rich artificial minerals providing great potential for
carbon capture to occur on human-relevant timescales. Steel slag was shown to weather
at a log rate of -9.39 to -11.88 mol Ca m-2 sec-1 in laboratory settings and -7.11 to -
7.56 mol Ca m-2 sec-1 under ambient environmental conditions in the field over 975
days.
Anthropogenic soils, known to contain substantial quantities of Ca and Mg-rich
minerals derived from industrial and demolition activity (including iron and steel slag,
cement and concrete), were systematically sampled across two field sites. Analysis
illustrated mean soil carbonate values of 21.8 ± 4.7% wt to 41.16 ± 9.89 wt %
demonstrating that a large quantity of soil carbonate forms and persists in these
environments, formed at a rate of 18kg CO2 t-1 a-1 . Stable isotope data ( 13C, 18O)
confirm that up to 81% of C in these pedogenic carbonates is atmospherically derived.
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C data also suggest that a significant proportion of the C present in carbonates
analysed is âmodernâ. Applying a current CO2 trading cost of ÂŁ8-ÂŁ12 t-1 CO2, the
potential value of CO2 sequestration at a study site was calculated to be ÂŁ51,843
ÂŁ77,765 ha-1 after 58% of its carbonation potential had been exploited.
The studies contained in this thesis add to a growing body of evidence for the formation
of carbonate minerals in soil settings where Ca/Mg-bearing silicate minerals occur.
They also support the idea that engineered soils could be effectively utilised for carbon
sequestration. Soil engineering for carbon capture provides a comparatively cheap, easy
and attractive way of beginning to offset the environmental impact of certain industrial
processes. Carbonation of waste silicates is a useful exercise in âclosing the loopâ on C
emissions produced in their manufacture. Carbon capture taking place on sites
containing industrial waste materials is of interest to a variety of stakeholders: site
owners, third sector bodies and local and national legislative bodies. Effective, low-
energy field-scale implementation of mineral carbonation through soil engineering
could assuage current constraints on economic performance of enhanced weathering
technologies and highlight the importance of soil carbon storage.Natural Environment Research Counci
Trade-offs and synergies in the ecosystem service demand of urban brownfield stakeholders
Brownfield site redevelopment presents an opportunity to create urban green spaces that provide a wide range of ecosystem services. It is important, therefore, to understand which ecosystem services are demanded by stakeholders and whether there are trade-offs or synergies in this demand. We performed a quantitative survey of ecosystem service demand from brownfield sites that included all major stakeholder groups. Results showed that there was a strong trade-off between demand for services related to property development (e.g. ground strength and low flood risk) and all other services, which were linked to vegetated sites. There was a secondary, but weak, trade-off between demand for services of more ânaturalâ vegetated sites (e.g. with a biodiversity protection role) and those linked to aesthetics and recreation. Stakeholders with a strong preference for biodiversity protection formed a distinct group in their ecosystem service demands. While a âdevelopmentâ vs âgreen spaceâ trade-off may be unavoidable, the general lack of strong trade-offs in demand for other services indicated that the creation of multifunctional greenspaces from former brownfield sites would be desirable to most stakeholders, as long as these are biophysically possible
Case studies on the effectiveness of capacity strengthening activities of the science granting councils initiative in Sub-Saharan Africa
The Science Granting Councils are at various stages in developing and implementing components of their science systems; for example, through deployment of learnings from the Science Granting Councils Initiative (SGCI) on public-private partnerships, and use of science, technology and innovation (STI) indicators in development and implementation of programmes. This report provides examples of how the SGCI has been effective and influential in context-dependent ways in the study countries. Findings suggest that all SGCs surveyed have been able to engage with, benefit from, and implement at least some of the trainings received by SGCI
Global Social Challenges for Development Studies in the Crisis in the Anthropocene
This panel discussion session explores some of the central dimensions of the Crisis in the Anthropocene that constitute global social challenges in the context of development studies. The conference theme highlighted the profound human impact on our blue-green-brown planet, that is already breaching planetary boundaries and pushing us beyond the roughly 1.5°C tipping point. This threatens liveability and sustainability in many localities and regions and may well rapidly be âoff the scaleâ of imaginability and survivability. Inevitably, as mounting empirical evidence and increasingly clear projections by the IPCC and other authoritative bodies show, these impacts are unevenly spread, both socially and spatially, both now and over the coming decades. The urgency of appropriate action is undeniable and we already know many dimensions of the required adaptations and transformations. Yet progress mostly remains too slow. These challenges are vital to the development studies community â heterogenous as it is â with our concerns for tackling poverty, inequality, deprivation and environmental degradation globally and locally.Hence this symposium asks what the crisis means for development theory, policy and practice and what development studies can and should be contributing to â and, indeed, whether it is capable of â addressing some key dimensions that warrant greater attention.Keywords: Crisis of the Anthropocene; development challenges; climate change; human security; circular economy; development finance; planetary healt
Global social challenges for development studies in the Crisis in the Anthropocene
This panel discussion session explores some of the central dimensions of the Crisis in the Anthropocene that constitute global social challenges in the context of development studies. The conference theme highlighted the profound human impact on our blue-green-brown planet, that is already breaching planetary boundaries and pushing us beyond the roughly 1.5°C tipping point. This threatens liveability and sustainability in many localities and regions and may well rapidly be âoff the scaleâ of imaginability and survivability. Inevitably, as mounting empirical evidence and increasingly clear projections by the IPCC and other authoritative bodies show, these impacts are unevenly spread, both socially and spatially, both now and over the coming decades. The urgency of appropriate action is undeniable and we already know many dimensions of the required adaptations and transformations. Yet progress mostly remains too slow. These challenges are vital to the development studies community â heterogenous as it is â with our concerns for tackling poverty, inequality, deprivation and environmental degradation globally and locally.
Hence this symposium asks what the crisis means for development theory, policy and practice and what development studies can and should be contributing to â and, indeed, whether it is capable of â addressing some key dimensions that warrant greater attention
Engaging at the science-policy interface as an early-career researcher: experiences and perceptions in biodiversity and ecosystem services research
Effective knowledge exchange at science-policy interfaces (SPIs) can foster evidence-informed policy-making through the integration of a wide range of knowledge inputs. This is especially crucial for conservation and sustainable use of biodiversity and ecosystem services (ES), human well-being and sustainable development. Early-career researchers (ECRs) can contribute significantly to knowledge exchange at SPIs. Recognizing that, several capacity building programs focused on sustainability have been introduced recently. However, little is known about the experiences and perceptions of ECRs in relation to SPIs. Our study focused on SPI engagement of ECRs who conduct research on biodiversity and ES, as perceived and experienced. Specifically, we addressed âmotivationsâ, âbarriersâ and âopportunities and âbenefitsâ. A total of 145 ECRs have completed the survey. Our results showed that ECRs were generally interested to engage in SPIs and believed it to be beneficial in terms of contributing to societal change, understanding policy processes and career development. Respondents perceived lack of understanding about involvement channels, engagement opportunities, funding, training, perceived credibility of ECRs by other actors and encouragement of senior colleagues as barriers to engaging in SPIs. Those who have already participated in SPIs generally saw fewer barriers and more opportunities. A key reason for dissatisfaction with experience in SPIs was a lack of impact and uptake of science-policy outputs by policymakersâan issue that likely extends beyond ECRs and implies the need for transformations in knowledge exchange within SPIs. In conclusion, based on insights from our survey, we outline several opportunities for increased and better facilitation of ECR engagement in SPIs. © 2022 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
Head in the clouds, feet on the ground: how transdisciplinary learning can foster transformative changeâinsights from a summer school
There is a pressing need for transformative change, with a vision of long-term human well-being within planetary boundaries. The lack of progressâdespite increasing awareness and actionâillustrates how challenging it is to foster change in our complex global society. Education and learning are needed to enable change. Transdisciplinary learning, which meaningfully integrates diverse knowledge and perspectives, contributes to developing an integrative understandingâa necessity for tackling complex challenges. We explore how transdisciplinary learning for early-career researchers can foster transformative change and lead to increased biodiversity conservation. This paper focuses on a case study of the authorsâ shared experiences during the 2021 Alternet Summer School, which focused on transformative change for biodiversity conservation and human well-being. In this introspective research, we gained insights through an online survey for participants and organizers of the summer school (nâ=â27). Using qualitative content analysis, we identify seven crucial elements of transdisciplinary learning which can lead to transformative change on (a) a personal level, as the learning process shifts values and helps researchers identify their roles; (b) a research level, by rethinking science and providing tools for transdisciplinary approaches, and (c) a societal level, by moving from the individual to the collective and constructing a shared vision for a sustainable future. Participants highlighted how changes on all these levels could benefit biodiversity conservation. These insights point to the benefit of transdisciplinary learning opportunities that empower young researchers to take up their part in fostering transformative change
Exploring human-nature relationships in academic literature on the nitrogen cycle
The nitrogen (N) cycle is a familiar concept. As is the much simplified, often diagrammatic, representation commonly used to illustrate the scale, importance and interconnectedness of this global cycle that links air, water, rocks and living beings. However, in this representation, humans are often presented as a seemingly minor entity or not explicitly shown at all. This can obscure the idea that humanity is both a direct beneficiary of the nitrogen cycle (through food and resources) and an increasingly significant influence on its function. This study sought to understand how diverse Human-Nature relationships (HNR) are expressed in recent academic literature on the nitrogen cycle. A sample of peer-reviewed literature, containing explicit and inferred examples of HNR and the nitrogen cycle, was analysed using two approaches: 1) network analysis, identifying and illustrating all quantifiable links made between components of the nitrogen cycle, and 2) content analysis to understand how different kinds of terminology were being used to describe relationships between components in the cycle. The network analysis revealed diverse links between âhumanâ and ânon-human natureâ. The content analysis found some explicit use of relational terms, most commonly âdepend*â. Both approaches highlighted strongly reciprocal links within the âhumanâ realm and the explicit centrality in which this is held across the corpus. We demonstrate the utility of combining quantitative and qualitative analysis to understand nuanced relationships in the nitrogen cycle and explore the utility this has to increase the acknowledgement and appreciation of HNR in science communication and science-policy interface work