1,298 publications from this institution
The aggregate technical potential for land-based negative emissions technologies (NETs) in the UK is estimated to be 12–49 Mt C eq. per year, representing around 8–32% of current emissions.
Abstract Soils are subject to varying degrees of direct or indirect human disturbance, constituting a major global change driver. Factoring out natural from direct and indirect human influence is not always straightforward, but some human activities have clear impacts. These include land‐use change, land management and land degradation (erosion, compaction, sealing and salinization). The intensity of land use also exerts a great impact on soils, and soils are also subject to indirect impacts arising from human activity, such as acid deposition (sulphur and nitrogen) and heavy metal pollution. In this critical review, we report the state‐of‐the‐art understanding of these global change pressures on soils, identify knowledge gaps and research challenges and highlight actions and policies to minimize adverse environmental impacts arising from these global change drivers. Soils are central to considerations of what constitutes sustainable intensification. Therefore, ensuring that vulnerable and high environmental value soils are considered when protecting important habitats and ecosystems, will help to reduce the pressure on land from global change drivers. To ensure that soils are protected as part of wider environmental efforts, a global soil resilience programme should be considered, to monitor, recover or sustain soil fertility and function, and to enhance the ecosystem services provided by soils. Soils cannot, and should not, be considered in isolation of the ecosystems that they underpin and vice versa. The role of soils in supporting ecosystems and natural capital needs greater recognition. The lasting legacy of the International Year of Soils in 2015 should be to put soils at the centre of policy supporting environmental protection and sustainable development.
This special issue provides an assessment of the contribution of soils to Nature's Contributions to People (NCP). Here, we combine this assessment and previously published relationships between NCP and delivery on the UN Sustainable Development Goals (SDGs) to infer contributions of soils to the SDGs. We show that in addition to contributing positively to the delivery of all NCP, soils also have a role in underpinning all SDGs. While highlighting the great potential of soils to contribute to sustainable development, it is recognized that poorly managed, degraded or polluted soils may contribute negatively to both NCP and SDGs. The positive contribution, however, cannot be taken for granted, and soils must be managed carefully to keep them healthy and capable of playing this vital role. A priority for soil management must include: (i) for healthy soils in natural ecosystems, protect them from conversion and degradation; (ii) for managed soils, manage in a way to protect and enhance soil biodiversity, health and sustainability and to prevent degradation; and (iii) for degraded soils, restore to full soil health. We have enough knowledge now to move forward with the implementation of best management practices to maintain and improve soil health. This analysis shows that this is not just desirable, it is essential if we are to meet the SDG targets by 2030 and achieve sustainable development more broadly in the decades to come. This article is part of the theme issue ‘The role of soils in delivering Nature's Contributions to People’.
Heating Degree Days (HDD), in cases where temperatures are below 18°C, and Cooling Degree Days (CDD), in cases where temperatures are above 21°C, were used as energy consumption indices. During the last half century, mean annual temperatures have increased and as a consequence, CDD in the warm season have increased sharply. In the same time slice, HDD, even in the cool and cold season have declined steadily. The number of monthly and annual total HDD (mean= 1556) are much higher than CDD (mean=400) in the case study area and annual total HDD and CDD have a negative correlation (Pearson correlation = - 0.493; p = 0.001). The deceasing rate of HDD is limited and steady (R2= 0.062, p=0.099), but the increasing rate of CDD in the same time slice is sharp (R2=0.427, p=0.813). This shows that energy consumption patterns have increased sharply, and with available projection scenarios, is projected to increase more rapidly, leading to higher energy costs.
Abstract Faced with accelerating climate change and growing food insecurity, sustainable agriculture has the potential to address both issues by enhancing soil carbon sequestration and crop yields. However, it remains unclear whether and when sustainable agricultural practices create win-wins or trade-offs between soil carbon sequestration and food production, and how these outcomes vary across crop types, practice combinations, and environmental conditions. We conducted a global meta-analysis of 2,975 paired yield and topsoil carbon observations (and 498 subsoil carbon observations) from 487 articles to assess the simultaneous impacts of reduced tillage, cover cropping, complex crop rotations, and crop residue retention on soil organic carbon stocks and maize, wheat, rice, and soybean yields. Our analysis revealed that sustainable agricultural practices generally enhanced soil carbon and crop yields, although with considerable heterogeneity. Individual practices often resulted in management trade-offs, as different practices (and crop-practice combinations) optimized either yields or soil carbon sequestration. However, practice stacking often alleviated these trade-offs by combining complementary practices. Win-wins were most likely in marginal agricultural lands characterized by warmer temperatures, water limitation, and low nitrogen application rates – conditions that represent a substantial proportion of global agricultural land area. However, our analysis revealed that the subsoil carbon responses to sustainable agricultural practices were highly variable and may offset topsoil gains, which may limit effective policy design and large-scale implementation.
Abstract. The Marrakech Accords allow biospheric carbon sinks and sources to be included in attempts to meet emission reduction targets for the first commitment period of the Kyoto Protocol. Forest management, cropland management, grazing land management and re‐vegetation are allowable activities under Article 3.4 of the Kyoto Protocol. Soil carbon sinks and sources can therefore be included under these activities. The Kyoto Protocol states that sinks and sources of carbon should be accounted for ‘taking into account uncertainties, transparency in reporting, verifiability’. At its most stringent, verifiability would entail the sampling of each geo‐referenced piece of land subject to an Article 3.4 activity at the beginning and end of a commitment period, using a sampling regime that gives adequate statistical power. Soil and vegetation samples and records would be archived and the data from each piece of land aggregated to produce a national figure. Separate methods would be required to deliver a second set of independent verification data. Such an undertaking at the national level would be prohibitively expensive. At its least stringent, verifiability would entail the reporting of areas under a given practice (without geo‐referencing) and the use of default values for a carbon stock change for each practice, to infer a change for all areas under that practice. A definition of verifiability between these extremes would allow simple methods, such as those derived from IPCC default values for CO 2 fluxes from soil, to be used for estimating changes in soil carbon. These may enable low‐level verifiability to be achieved by most parties by the beginning of the first commitment period (2008–2012).
Energy efficiency and greenhouse gas emissions are closely linked. This paper reviews agricultural options to reduce energy intensities and their impacts, discusses important accounting issues related to system boundaries, land scarcity, and measurement units, and compares agricultural energy intensities and improvement potentials on an international level. Agricultural development in the past decades, while increasing yields, led to lower average energy efficiencies between the sixties and mid eighties. In the last two decades, energy intensities in developed countries increased, however, with little impact on greenhouse gas emissions. Efficiency differences across countries suggest a maximum improvement potential of 500 million tons of CO2 annually.
Terrestrial ecosystems, comprising vegetation and soil in uplands and wetlands, significantly impact the global carbon (C) cycle and, under natural conditions, are a sink of atmospheric carbon dioxide (CO2) and methane (CH4). However, conversion of natural to managed ecosystems (i.e., agroecosystems, urban lands, and mined lands) depletes ecosystem C stocks, aggravates gaseous emissions, and exacerbates radiative forcing. Thus, the onset of agriculture around 8000 BC presumably transformed these sinks into a source of greenhouse gases (GHGs) (Ruddiman 2003), mostly CO2, CH4, and nitrous oxide (N2O), and depleted the terrestrial (soil, vegetation, and peatlands) C stocks. Ruddiman (2005) estimated the depletion of the terrestrial C stock (soil and vegetation) by 456 Pg (502.65 × 109 tn) since the onset of agriculture. Of this, the historic depletion of soil organic carbon (SOC) stock is estimated at 130 to 135 Pg (143.3 × 109 to 148.8 × 109 tn) (Sanderman et al. 2017; Lal 2018). Therefore, recarbonization of some of the terrestrial biosphere (soil and vegetation) is an important strategy to mitigate the anthropogenic climate change (ACC) and enhance other ecosystem services because of the link between SOC stock and atmospheric concentration of CO2 (Trenberth and Smith 2005).
