Abstract. Soil organic carbon (SOC), one of the largest terrestrial carbon (C) stocks on Earth, has been depleted by anthropogenic land cover change and agricultural management. However, the latter has so far not been well represented in global C stock assessments. While SOC models often simulate detailed biochemical processes that lead to the accumulation and decay of SOC, the management decisions driving these biophysical processes are still little investigated at the global scale. Here we develop a spatially explicit data set for agricultural management on cropland, considering crop production levels, residue returning rates, manure application, and the adoption of irrigation and tillage practices. We combine it with a reduced-complexity model based on the Intergovernmental Panel on Climate Change (IPCC) tier 2 method to create a half-degree resolution data set of SOC stocks and SOC stock changes for the first 30 cm of mineral soils. We estimate that, due to arable farming, soils have lost around 34.6 GtC relative to a counterfactual hypothetical natural state in 1975. Within the period 1975–2010, this SOC debt continued to expand by 5 GtC (0.14 GtC yr−1) to around 39.6 GtC. However, accounting for historical management led to 2.1 GtC fewer (0.06 GtC yr−1) emissions than under the assumption of constant management. We also find that management decisions have influenced the historical SOC trajectory most strongly by residue returning, indicating that SOC enhancement by biomass retention may be a promising negative emissions technique. The reduced-complexity SOC model may allow us to simulate management-induced SOC enhancement – also within computationally demanding integrated (land use) assessment modeling.
Abstract Many neurological problems are episodic, so that cases appear normal when examined in the consulting room. Now that almost everybody walks around with a good quality video camera in their pocket, there's plenty of opportunity for clients to record these problems as they occur, making it much easier to understand the nature of the problem. Unfortunately, owner videos come in a variety of shapes and sizes and clients will sometimes expect you to reach a decision on the spot. Quality can be poor, with grainy, poorly focused images, shaky footage and low lighting. It can even be difficult to determine the precise nature of the abnormality being illustrated. Overall, however, client videos should be viewed as an invaluable asset in deciding how best to investigate a problem. Learning Objectives: To have some insight into the difference between seizure activity and other sporadic episodes of collapse To recognise that neurological disease can mimic other causes of collapse and weakness To appreciate that owner videos are an asset in determining the nature of collapse.
With a growing population with changing demands, competition for the global land resource is increasing. We need to feed a projected population of 9–10 billion by 2050, rising to approximately 12 billion by 2100. At the same time, we need to reduce the climate impact of agriculture, forestry and other land use, and we almost certainly need to deliver land-based greenhouse gas removal for additional climate change mitigation. In addition, we need to deliver progress towards meeting the United Nations Sustainable Development Goals, all without compromising the many ecosystem services provided by land and without exceeding planetary boundaries. Managing the land to tackle these pressing issues is a major global challenge. In this perspective paper, I provide a very broad overview of the main challenges, and explore co-benefits, trade-offs and possible solutions.
No abstract is provided for this article.
The stable block at Audley End, brick and multi-gabled, stands in contrast to the classical stone palace built on the opposite side of the River Cam by Thomas Howard, 1st Earl of Suffolk, early in the reign of James I. Its contrasting appearance and domestic character generated much antiquarian speculation about its age and original purpose. It is now clear that it is contemporary with the palace, built for a specific but essentially domestic function, and soon converted to serve as the stable block and coach house. This article seeks to elucidate the form of the building in its 17th century phases, and outline the context that produced them.
The challenge facing society in the 21st century is to improve the quality of life for all citizens in an egalitarian way, providing sufficient food, shelter, energy, and other resources for a healthy meaningful life, while at the same time decarbonizing anthropogenic activity to provide a safe global climate, limiting temperature rise to well-below 2°C with the aim of limiting the temperature increase to no more than 1.5°C. To do this, the world must achieve net zero greenhouse gas (GHG) emissions by 2050. Currently spreading wealth and health across the globe is dependent on growing the GDP of all countries, driven by the use of energy, which until recently has mostly been derived from fossil fuel. Recently, some countries have decoupled their GDP growth and greenhouse gas emissions through a rapid increase in low carbon energy generation. Considering the current level of energy consumption and projected implementation rates of low carbon energy production, a considerable quantity of fossil fuels is projected to be used to fill the gap, and to avoid emissions of GHG and close the gap between the 1.5°C carbon budget and projected emissions, carbon capture and storage (CCS) on an industrial scale will be required. In addition, the IPCC estimate that large-scale GHG removal from the atmosphere is required to limit warming to below 2°C using technologies such as Bioenergy CCS and direct carbon capture with CCS to achieve climate safety. In this paper, we estimate the amount of carbon dioxide that will have to be captured and stored, the storage volume, technology, and infrastructure required to achieve the energy consumption projections with net zero GHG emissions by 2050. We conclude that the oil and gas production industry alone has the geological and engineering expertise and global reach to find the geological storage structures and build the facilities, pipelines, and wells required. Here, we consider why and how oil and gas companies will need to morph from hydrocarbon production enterprises into net zero emission energy and carbon dioxide storage enterprises, decommission facilities only after CCS, and thus be economically sustainable businesses in the long term, by diversifying in and developing this new industry.
