Publications

Multilingual large language models, fine-tuning, and prompt engineering

Potential yield challenges to scale-up of zero budget natural farming

Re‐evaluating the biophysical and technologically attainable potential of topsoil carbon sequestration in <scp>C</scp> hina's cropland

Abstract To assess the topsoil carbon sequestration potential ( CSP ) of C hina's cropland, two different estimates were made: (i) a biophysical potential ( BP ) using a saturation limit approach based on soil organic carbon ( SOC ) accumulation dynamics and a storage restoration approach from the cultivation‐induced SOC loss, and (ii) a technically attainable potential ( TAP ) with a scenario estimation approach using SOC increases under best management practices ( BMPs ) in agriculture. Thus, the BP is projected to be the gap in recent SOC storage to either the saturation capacity or to the SOC storage of uncultivated soil, while the TAP is the overall increase over the current SOC storage that could be achieved with the extension of BMPs . The recent mean SOC density of C hina's cropland was estimated to be 36.44 t/ha, with a BP estimate of 2.21 Pg C by a saturation approach and 2.95 Pg C by the storage restoration method. An overall TAP of 0.62 Pg C and 0.98 Pg C was predicted for conservation tillage plus straw return and recommended fertilizer applications, respectively. This TAP is comparable to 40–60% of total CO 2 emissions from C hinese energy production in 2007. Therefore, carbon sequestration in C hina's cropland is recommended for enhancing C hina's mitigation capacity for climate change. However, priority should be given to the vast dry cropland areas of C hina, as the CSP of C hina is based predominantly on the dry cropland.

Land availability and policy commitments limit global climate mitigation from forestation

Forestation (afforestation and reforestation) could mitigate climate change by sequestering carbon within biomass and soils. However, global mitigation from forestation remains uncertain owing to varying estimates of carbon sequestration rates (notably in soil) and land availability. In this study, we developed global maps of soil carbon change that reveal carbon gains and losses with forestation, primarily in the topsoil. Constraining land availability to avoid unintended albedo-induced warming and safeguard water and biodiversity (389 million hectares available for forestation globally) would sequester 39.9 petagrams of carbon by 2050, substantially below previous estimates. This estimate drops to 12.5 petagrams of carbon with land further limited to existing policy commitments (120 million hectares). Achieving greater mitigation requires expanding dedicated forestation areas and strengthening commitments from nations with considerable but untapped potential.

Comparing options for atmospheric greenhouse gas removal

Environmental Research 2021 takes place at a critical time as the world tries to find global solutions to issues aligned with the UN’s Sustainable Development Goals. It will be one of the first major international scientific events taking place after COP26, providing the perfect platform to discuss key aspects from the world leaders’ talks. You can join live-streamed presentations from diverse voices, topical panel discussions, poster sessions and interactive networking opportunities. Environmental Research 2021 will unite a broad cross-section of communities – environmental and social scientists, engineers and policy influencers – at all career stages. The scientific programme has been designed around five core themes of: 1. Climate science 2. Energy 3. Infrastructure and sustainability 4. Environmental and global health 5. Ecology and biodiversity

Effects of carbonate minerals and exogenous acids on carbon flux from the chemical weathering of granite and basalt

UK land-use change and its impact on SOC: 1925-2007

[1] The contribution of soil organic carbon (SOC) to atmospheric greenhouse gas (GHG) concentrations could increase due to rising temperatures, agricultural land-management, and land-use change. Here the results of a modeling study are presented, which reviews the changing patterns of UK land-use from 1925 to 2007, and estimates the contribution that these changes have had toward UK GHG emissions. The study uses a large database of SOC concentrations from which SOC stocks are estimated for land-uses typical of the UK, and combines this with literature values of transition times for SOC to adjust to a new concentration following land-use change. The model was designed to be used with limited input data, allowing the impacts of historical land-use change, lacking in site specific soil and vegetation change data to be assessed. This study suggests that from 1925 to 2007 the UK's soils have acted as a net carbon sink as a result of land-use change, sequestering a total of 102 Tg C. This represents a 5% net gain in total SOC stocks, and an average increase of 1.9 Tg C/year (inter-quartile range: 0.19–3.12 Tg C/yr). When the reported losses of SOC due to climate change are compared to the gains resulting from land-use change the UK's soils are a sink of carbon, with the gains from land-use change offsetting those due to climate change. This overall sink is the result of an increase in the area of woodland, and conversion of arable land to permanent grassland. The greatest sequestration in any one year occurred in 1993 and coincides with the introduction of set-aside. The largest SOC flux to the atmosphere occurred in 1942 following arable expansion, emitting 12.3 Tg C in one year. This flux is equivalent to almost 10% of the UK's current total GHG emissions, indicating that such land-use change should be avoided in the future if targets to reduce GHG emissions are to be met.

Predicting Coupled Emissions of N2O, CO2 and CH4 from Arable Fields in Ireland Using the ECOSSE Model

Climate‐ and crop‐responsive emission factors significantly alter estimates of current and future nitrous oxide emissions from fertilizer use

Abstract The current Intergovernmental Panel on Climate Change (IPCC) default methodology (tier 1) for calculating nitrous oxide (N 2 O) emissions from nitrogen applied to agricultural soils takes no account of either crop type or climatic conditions. As a result, the methodology omits factors that are crucial in determining current emissions, and has no mechanism to assess the potential impact of future climate and land‐use change. Scotland is used as a case study to illustrate the development of a new methodology, which retains the simple structure of the IPCC tier 1 methodology, but incorporates crop‐ and climate‐dependent emission factors (EFs). It also includes a factor to account for the effect of soil compaction because of trampling by grazing animals. These factors are based on recent field studies in Scotland and elsewhere in the UK. Under current conditions, the new methodology produces significantly higher estimates of annual N 2 O emissions than the IPCC default methodology, almost entirely because of the increased contribution of grazed pasture. Total emissions from applied fertilizer and N deposited by grazing animals are estimated at 10 662 t N 2 O‐N yr −1 using the newly derived EFs, as opposed to 6 796 t N 2 O‐N yr −1 using the IPCC default EFs. On a spatial basis, emission levels are closer to those calculated using field observations and detailed soil modelling than to estimates made using the IPCC default methodology. This can be illustrated by parts of the western Ayrshire basin, which have previously been calculated to emit 8–9 kg N 2 O‐N ha −1 yr −1 and are estimated here as 6.25–8.75 kg N 2 O‐N ha −1 yr −1 , while the IPCC default methodology gives a maximum emission level of only 3.75 kg N 2 O‐N ha −1 yr −1 for the whole area. The new methodology is also applied in conjunction with scenarios for future climate‐ and land‐use patterns, to assess how these emissions may change in the future. The results suggest that by 2080, Scottish N 2 O emissions may increase by up to 14%, depending on the climate scenario, if fertilizer and land management practices remain unchanged. Reductions in agricultural land use, however, have the potential to mitigate these increases and, depending on the replacement land use, may even reduce emissions to below current levels.

Birddogs and Tough Old Broads

<JATS1:p>Birddogs and Tough Old Broads: Women Journalists of Mississippi and a Century of State Politics, 1880s-1980sdocuments the professional experiences and observations of more than a dozen journalists, all women, all covering Mississippi state politics over the course of a century—from the 1880s, right after the end of Reconstruction (when newspapers were the primary source of information) to the 1980s, a time period marked by steady declines in both news revenue and circulation, and the emergence of corporate journalism, led by media conglomerates like Gannett. Pete Smith argues that the experiences of the women journalists reflect broader social, political, legal, and cultural struggles and changes in both the South and the nation during the late nineteenth and twentieth centuries. The evolution of the modern-day political journalist, particularly for southern women who aspired to such a position, can be seen in their struggles and accomplishments.</JATS1:p>

Sequestering Carbon Dioxide by the Use of the Energy Crop Miscanthus:Quantifying the Energy Production and Sequestration Potential of Europe

Sequestering Carbon Dioxide by the Use of the Energy Crop Miscanthus: Quantifying the Energy Production and Sequestration Potential of Europe Astley F. Hastings; Astley F. Hastings The University of Aberdeen Search for other works by this author on: This Site Google Scholar John Clifton-Brown; John Clifton-Brown IGER Search for other works by this author on: This Site Google Scholar Martin Wattenbach; Martin Wattenbach University of Aberdeen Search for other works by this author on: This Site Google Scholar Paul Mitchell; Paul Mitchell University of Aberdeen Search for other works by this author on: This Site Google Scholar Pete Smith Pete Smith University of Aberdeen Search for other works by this author on: This Site Google Scholar Paper presented at the EUROPEC/EAGE Conference and Exhibition, London, U.K., June 2007. Paper Number: SPE-107495-MS https://doi.org/10.2118/107495-MS Published: June 11 2007 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Hastings, Astley F., Clifton-Brown, John, Wattenbach, Martin, Mitchell, Paul, and Pete Smith. "Sequestering Carbon Dioxide by the Use of the Energy Crop Miscanthus: Quantifying the Energy Production and Sequestration Potential of Europe." Paper presented at the EUROPEC/EAGE Conference and Exhibition, London, U.K., June 2007. doi: https://doi.org/10.2118/107495-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Europec featured at EAGE Conference and Exhibition Search Advanced Search AbstractGlobal warming caused by anthropological emissions of greenhouse gas (GHG) is now an inconvenient reality. CO2, the largest contributor, was emitted at the rate of 6 Gt C y-1 by burning fossil fuels in 1990, which are projected to rise to around 10 Gt C y-1 by 2020. Using bio-fuels, such as bio-ethanol or bio-diesel in transportation, or biomass in power generation reduces CO2 emissions as the carbon is fixed by the plants from the atmosphere and saves the equivalent fossil fuel.The biospheric flux of carbon from the soil and terrestrial biota to the atmosphere is about 120 Gt C y-1 and is roughly balanced by the fixation of carbon by photosynthesis. However, anthropological land use change, through increased agriculture and forestry, resulted in atmospheric emissions of 1.1 Gt C in 1990, projected to rise to 1.5 Gt C in 2020, so the production of biofuels is not GHG emission free if land use change is involved.This paper explores the GHG emission cost of the production of bio-fuels derived from energy crops and compares them to fossil fuels used in transport and electricity generation. The bio-fuels emission cost are presented for several land use scenarios showing that highest sequestration can be achieved by using existing arable land for bio-fuel production and not land with a currently undisturbed ecosystem.Considering these drivers and the GHG emissions, we model the future potential of Europe to produce bio-fuels with four different future land use and climate change scenarios and conclude that up to 20% of Europe's current primary energy consumption could be provided by bio-fuels by the year 2080 with a corresponding reduction in carbon emissions, taking into account the GHG cost of production.IntroductionThe global pattern of energy use is changing with the successive industrialization of the economies of South East Asia and Brazil, and more recently with the increasing pace of the industrialization of China and India. This has driven an increase in the demand for energy, and hence for fossil fuel, at the rate of 2–3% per year 1. The rate at which conventional oil production can be increased has been reduced by the lack of refining capacity, and the fact that nearly 50% of the world's proven and probable conventional light crude oil reserves have already been consumed 2. This flat-topping in the availability of oil has been compensated for by the increased availability of natural gas and new reserves of cheap coal. Natural gas has been increasing its share of the energy supply mix as the infrastructure and technology of its transportation is put into place both by pipelines, liquefaction and conversion to methanol. In developed economies, gas has displaced both oil and coal, whilst coal use has increased in developing economies, particularly in China. At the same time the use of nuclear energy has stagnated due to public concerns about waste storage and disposal.Globally, biomass currently provides around 46 EJ of bio-energy in the form of combustible biomass and wastes, liquid bio-fuels, renewable municipal solid waste, solid biomass/charcoal, and gaseous fuels. This share is estimated to be 13.4% of global primary energy supply 3 but this is mainly from "traditional biomass" estimated to provide 32EJ in 2002 of non-commercial firewood, charcoal and dung used for cooking and heating in developing countries 4. Such low-grade biomass provides around 35% of primary energy in many developing countries, but more than 70% in Africa 5. Keywords: climate change, grid block, Time Slice, Europe, coal, biomass, meteorological data, Upstream Oil & Gas, experiment, degree grid Subjects: Environment, Climate change This content is only available via PDF. 2007. Society of Petroleum Engineers You can access this article if you purchase or spend a download.

The economics of soil C sequestration and agricultural emissions abatement

Abstract. Carbon is a critical component of soil vitality and is crucial to our ability to produce food. Carbon sequestered in soils also provides a further regulating ecosystem service, valued as the avoided damage from global climate change. We consider the demand and supply attributes that underpin and constrain the emergence of a market value for this vital global ecosystem service: markets being what economists regard as the most efficient institutions for allocating scarce resources to the supply and consumption of valuable goods. This paper considers how a potentially large global supply of soil carbon sequestration is reduced by economic and behavioural constraints that impinge on the emergence of markets, and alternative public policies that can efficiently transact demand for the service from private and public sector agents. In essence, this is a case of significant market failure. In the design of alternative policy options, we consider whether soil carbon mitigation is actually cost-effective relative to other measures in agriculture and elsewhere in the economy, and the nature of behavioural incentives that hinder policy options. We suggest that reducing the cost and uncertainties of mitigation through soil-based measures is crucial for improving uptake. Monitoring and auditing processes will also be required to eventually facilitate wide-scale adoption of these measures.

Marginal abatement cost curves for UK agriculture, forestry, land-use and land-use change sector out to 2022

Greenhouse gas emissions from agriculture, land use, land use change and forestry (ALULUCF) are a significant percentage of UK industrial emissions. The UK Government is committed to ambitious targets for reducing emissions and all significant industrial sources are coming under increasing scrutiny. The task of allocating shares of future reductions falls to the newly appointed Committee on Climate Change (CCC), which needs to consider efficient mitigation potential across a range of sectors. Marginal abatement cost curves are derived for a range of mitigation measures in the agriculture and forestry sectors over a range of adoption scenarios and for the years 2012, 2017 and 2022. The results indicate that in 2022 around 6.36 MtCO2e could be abated at negative or zero cost. Further, in same year over 17% of agricultural GHG emissions (7.85MtCO2e) could be abated at a cost of less than the 2022 Shadow Price of Carbon (£34tCO2e).

Author Correction: Stakeholder-driven transformative adaptation is needed for climate-smart nutrition security in sub-Saharan Africa

Did the study involve field work?Yes NoReporting for specific materials, systems and methodsWe require information from authors about some types of materials, experimental systems and methods used in many studies.Here, indicate whether each material, system or method listed is relevant to your study.If you are not sure if a list item applies to your research, read the appropriate section before selecting a response.

Ammonium enrichment in livestock manure driven by ammonia-abatement practices can reduce nitrous oxide emissions

Conservation tillage systems: a review of its consequences for greenhouse gas emissions

Abstract Conservation tillage ( CT ) is an umbrella term encompassing many types of tillage and residue management systems that aim to achieve sustainable and profitable agriculture. Through a global review of CT research, the objective of this paper was to investigate the impacts of CT on greenhouse gas ( GHG ) emissions. Based on the analysis presented, CT should be developed within the context of specific climates and soils. A number of potential disadvantages in adopting CT practices were identified, relating mainly to enhanced nitrous oxide emissions, together with a number of advantages that would justify its wider adoption. Almost all studies examined showed that the adoption of CT practices reduced carbon dioxide emissions, while also contributing to increases in soil organic carbon and improvements in soil structure.

Carbon implications of converting cropland to bioenergy crops or forest for climate mitigation: a global assessment

Abstract The potential for climate change mitigation by bioenergy crops and terrestrial carbon sinks has been the object of intensive research in the past decade. There has been much debate about whether energy crops used to offset fossil fuel use, or carbon sequestration in forests, would provide the best climate mitigation benefit. Most current food cropland is unlikely to be used for bioenergy, but in many regions of the world, a proportion of cropland is being abandoned, particularly marginal croplands, and some of this land is now being used for bioenergy. In this study, we assess the consequences of land‐use change on cropland. We first identify areas where cropland is so productive that it may never be converted and assess the potential of the remaining cropland to mitigate climate change by identifying which alternative land use provides the best climate benefit: C 4 grass bioenergy crops, coppiced woody energy crops or allowing forest regrowth to create a carbon sink. We do not present this as a scenario of land‐use change – we simply assess the best option in any given global location should a land‐use change occur. To do this, we use global biomass potential studies based on food crop productivity, forest inventory data and dynamic global vegetation models to provide, for the first time, a global comparison of the climate change implications of either deploying bioenergy crops or allowing forest regeneration on current crop land, over a period of 20 years starting in the nominal year of 2000 ad . Globally, the extent of cropland on which conversion to energy crops or forest would result in a net carbon loss, and therefore likely always to remain as cropland, was estimated to be about 420.1 Mha, or 35.6% of the total cropland in Africa, 40.3% in Asia and Russia Federation, 30.8% in Europe‐25, 48.4% in North America, 13.7% in South America and 58.5% in Oceania. Fast growing C 4 grasses such as Miscanthus and switch‐grass cultivars are the bioenergy feedstock with the highest climate mitigation potential. Fast growing C 4 grasses such as Miscanthus and switch‐grass cultivars provide the best climate mitigation option on ≈485 Mha of cropland worldwide with ~42% of this land characterized by a terrain slope equal or above 20%. If that land‐use change did occur, it would displace ≈58.1 Pg fossil fuel C equivalent (C eq oil). Woody energy crops such as poplar, willow and Eucalyptus species would be the best option on only 2.4% (≈26.3 Mha) of current cropland, and if this land‐use change occurred, it would displace ≈0.9 Pg C eq oil. Allowing cropland to revert to forest would be the best climate mitigation option on ≈17% of current cropland (≈184.5 Mha), and if this land‐use change occurred, it would sequester ≈5.8 Pg C in biomass in the 20‐year‐old forest and ≈2.7 Pg C in soil. This study is spatially explicit, so also serves to identify the regional differences in the efficacy of different climate mitigation options, informing policymakers developing regionally or nationally appropriate mitigation actions.

Complex controls on nitrous oxide flux across a long elevation gradient in the tropical Peruvian Andes

Abstract. Current bottom-up process models suggest that montane tropical ecosystems are weak atmospheric sources of N2O, although recent empirical studies from the southern Peruvian Andes have challenged this idea. Here we report N2O flux from combined field and laboratory experiments that investigated the process-based controls on N2O flux from montane ecosystems across a long elevation gradient (600–3700 m a.s.l.) in the southern Peruvian Andes. Nitrous oxide flux and environmental variables were quantified in four major habitat types (premontane forest, lower montane forest, upper montane forest and montane grassland) at monthly intervals over a 30-month period from January 2011 to June 2013. The role of soil moisture content in regulating N2O flux was investigated through a manipulative, laboratory-based 15N-tracer experiment. The role of substrate availability (labile organic matter, NO3−) in regulating N2O flux was examined through a field-based litter-fall manipulation experiment and a laboratory-based 15N-NO3− addition study. Ecosystems in this region were net atmospheric sources of N2O, emitting 0.27 ± 0.07 mg N-N2O m−2 d−1. Nitrous oxide flux was inversely related to elevation; N2O flux was greatest in premontane forest (0.75 ± 0.18 mg N-N2O m−2 d−1), followed by lower montane forest (0.46 ± 0.24 mg N-N2O m−2 d−1), montane grasslands (0.07 ± 0.08 mg N-N2O m−2 d−1), and upper montane forest (0.04 ± 0.07 mg N-N2O m−2 d−1). Nitrous oxide flux showed weak seasonal variation across the region; only lower montane forest showed significantly higher N2O flux during the dry season compared to wet season. Manipulation of soil moisture content in the laboratory indicated that N2O flux was significantly influenced by changes in water-filled pore space (WFPS). The relationship between N2O flux and WFPS was bimodal and non-linear, diverging from theoretical predictions of how WFPS relates to N2O flux. Nitrous oxide flux was greatest at 90 and 50 % WFPS, and lowest at 70 and 30 % WFPS. This bimodal distribution of N2O flux suggests a complex relationship between WFPS, environmental variables, and nitrate-reducing processes. Changes in labile organic matter inputs, through the manipulation of leaf litter-fall, did not alter N2O flux, suggesting that litter inputs have a negligible impact on N2O flux. Nitrate addition experiments demonstrated that variations in NO3− availability constrained N2O flux. Habitat – a proxy for NO3− availability under field conditions – was the best predictor for N2O flux, with N-rich habitats (premontane forest, lower montane forest) showing significantly higher N2O flux than N-poor habitats (upper montane forest, montane grassland). Nitrous oxide flux did not respond to short-term changes in NO3− concentration.