The role of technical improvements in decarbonising passenger transport

Passenger vehicles are a leading driver of anthropogenic greenhouse gas (GHG) emissions. The majority of efforts to reduce vehicle GHG emissions focus on technical improvements, due to difficulties in reducing travel demand and shifting to alternative modes of travel. However, the rate at which technical improvements can be deployed is highly uncertain. Furthermore, the benefits of technical efficiency improvements may be offset by consumer trends towards larger and more powerful vehicles, filled with a greater number of accessories. Similarly, efficiency improvements can lower running costs, which may stimulate drivers to travel more. These consumer trends create further uncertainty about the impact of technical improvements. The aim of this thesis is to estimate the extent to which future technical improvements might be offset by consumer trends, and the risks they pose to reducing CO2 emissions. Firstly, technical efficiency improvements in vehicles over the past two decades are quantified, using driver-reported data for the first time. This is important as vehicle fuel consumption reported by drivers on the road is found to be ≈35% higher than official tested values in 2017-18. The analysis shows that technical improvements had the potential to reduce fuel consumption by 1.8 L/100km between 2001 and 2018. However, two thirds of this potential was offset by the increasing size and power of vehicles. Finally, the introduction of new EU vehicle efficiency regulations in 2008/09 is found to have had little effect at stimulating the rate of real technical efficiency improvements in British vehicles. If efficiency improvements stimulate drivers to travel more, due to lower running costs, potential emissions reductions from technical improvements may be further offset. Past estimates of the magnitude of this effect, known as the Rebound Effect, have varied widely, partly due to data constraints and a reliance upon highly aggregated government statistics. The analysis of this thesis instead uses a novel dataset of over 275 million vehicle road-worthiness tests. Results show that the Rebound Effect in Great Britain is small, with magnitude 4.6%, meaning efficiency improvements are unlikely to greatly stimulate increased mileage. Having quantified the extent to which technical efficiency improvements in vehicles have been offset by consumer trends in the recent past, the analysis then explores their future role. A range of technology and policy actions can be put in place to reduce carbon emissions, this thesis aims to prioritise between them, based upon their likely impact and uncertainty. Formal sensitivity analysis techniques are used for the first time to determine the relative importance of factors affecting future emissions from passenger vehicles. The findings show that over 80% of the uncertainty in future cumulative CO2 emissions can be attributed to uncertainty in electric vehicle uptake and vehicle size and power. These variables are therefore of primary importance for transport policy makers. The analysis also highlights variables of comparatively low importance; these include the carbon intensity of the electricity grid, the share of hybrid electric vehicles, the magnitude of the Rebound Effect and the rate of incremental improvements within powertrain technologies. The core contribution of this thesis is to compare efforts to improve the technical efficiency of vehicles, with the impacts of consumer trends and factors affecting future transport emissions. The majority of potential emissions savings from engineering improvements in the past two decades have been lost, strong policy action is required to avoid this trend continuing in future.This work was funded under EPSRC grant numbers: EP/M506485/1 and EP/M508007/1

Ebola virus disease epidemic in West Africa: Lessons learned and issues arising from West African countries

© Royal College of Physicians 2015. All rights reserved.The current Ebola virus disease (EVD) outbreak ravaging three nations in West Africa has affected more than 14,000 persons and killed over 5,000. It is the longest and most widely spread Ebola epidemic ever seen. At the time of this overview (written November 2014), having affected eight different nations, Nigeria and Senegal were able to control and eliminate the virus within a record time. Ghana has successfully, to date, kept the virus away from the country, despite economic and social relationships with affected nations. What lessons can we learn from Nigeria, Senegal and Ghana in the current epidemic? How can the world improve the health systems in low- and middle-income countries to effectively manage future outbreaks? Recently, the Royal College of Physicians launched a new partnership with the West African College of Physicians to curtail the effects of HIV/AIDS, malaria and tuberculosis in the region. We believe that strengthened health systems, skilled human resources for health and national ownership of problems are key to effective management of outbreaks such as EVD

The transient behaviour of through-flowing gravity currents interacting with a roughness array

We present laboratory experiments that investigate the structure and flow characteristics of gravity currents travelling through an array of roughness elements. The roughness elements are of comparable height to the gravity current such that the current flows through the roughness array rather than over it. The frontal velocity and density structure are measured as the current transitions from flowing along a smooth bed to flowing through the roughness array, and then back to a smooth bed. We find that, upon entering the roughness array, the gravity current decelerates and the density structure changes from the head and tail structure typical of smooth bed gravity currents, to a wedge shape. A model is presented that explains the deceleration and change in shape based on a dynamic balance between a pressure gradient within the current tail and a drag force associated with individual roughness elements. This model accurately predicts the deceleration of the gravity current, supporting the proposed dynamic balance.Comment: Submitted to Physical Review of Fluids. 19 pages, 16 figure

'The Blessed Land': Narratives of Peasant Resistance at Nandigram, West Bengal, in 2007

In early 2007, the West Bengal state government in India sought to acquire over 10,000 acres of cultivated rural land in Nandigram, East Midnapur. The government, the Communist Party of India (Marxist) (CPI-M) led Left Front coalition, sought to acquire this land to allow the Indonesian industrialists, the Salim group, to construct a chemical hub. Land acquisition had been increasing in India since 2005, when the Special Economic Zone (SEZ) Act was passed for the purpose of attracting investment from national and multinational corporations. Peasants in Nandigram were opposed to the acquisition of their land, and during 2007 successfully resisted the government attempts to do so. In response, the CPI-M sent party cadre to harass, rape and murder the peasantry, using their control of government to punish people in Nandigram. This thesis examines the events at Nandigram between June 2006 and May 2008 and investigates the narratives of peasant resistance that emerged in West Bengal. It focuses on three groups of West Bengal society: the peasants of Nandigram, the intellectuals and civil society of West Bengal, and the major political parties of West Bengal. Existing explanations of the events at Nandigram have focused on the role of intellectuals and civil society, and their views have dominated the literature. The existing historiography has argued that land acquisition policies and the subsequent resistance at Nandigram were an effect of neoliberal policies, policies that had been pursued by both the central and state governments in India since the 1990s. Resistance at Nandigram was explained as a broad movement that involved the peasantry and adivasi, but also the civil society groups that opposed neoliberal policies. However, as this thesis demonstrates, the peasantry at Nandigram rarely articulated their resistance as 'against' neoliberalism, and there was little consciousness of the movement challenging neoliberal policies. Rather, it was the local conditions and history of the area that informed their resistance. Amongst intellectuals and civil society, only a minority connected resistance at Nandigram to the wider issue of neoliberalism. The dominant perspective of these groups was that land acquisition policies, and neoliberal reforms in general, were necessary for the development of West Bengal. They criticised the CPI-M only for badly managing the process of land acquisition. The neoliberal consensus extended to the West Bengal political parties, muting serious debate over the economic direction of the state. The discourse of the political parties was limited to allegations of corruption, violence and criminality. Therefore, an investigation of how people in West Bengal viewed the resistance at Nandigram shows that discontent was not generally articulated in opposition to neoliberal polices. Rather, local politics and local issues had a more immediate effect on people's views, focusing discontent on the governance of the CPI-M. This resulted in the resistance at Nandigram evolving into a movement that sought to challenge the continued rule of the CPI-M in West Bengal

Towards cultural competence : Australian Indigenous content in undergraduate psychology

This paper discusses the development and preliminary analysis of psychology undergraduate courses on cultural competence in relation to Indigenous Australians. The paper summarises the process that led to the formation of draft curriculum guidelines for psychology academics, including the need to critically examine the assumptions and history of Western psychology in relation to Indigenous peoples, the inclusion of non-conventional teaching and learning methods, staff and institutional support, and appropriate staff development. The paper then discusses the responses of students to one of the courses developed from these guidelines. The courses were well received by students and although they do not in themselves teach professional psychological skills in working effectively with Indigenous people, they provide a solid basis for the development of such skills. Because this is a relatively new area, it is likely that there will be much refinement of these courses in coming years. <br /

Experiments on the interaction of ice sheets with the polar oceans

Antarctica and Greenland have been losing mass at an increasing rate over recent decades. The reducing volume of ice in Antarctica and Greenland has been a significant contribution to global sea level rise and will continue to be so in the future. Much of the mass loss occurs at the edge of the ice sheets where glaciers flow into the ocean. Interactions between the ice and the ocean are important in controlling the ablation rate of the glaciers. As such, there has been much recent work examining the response of ice shelves to changing ocean conditions. The majority of this work has used numerical models that allow a range of ocean conditions to be simulated. Here, we investigate the major ice-ocean interactions through idealized laboratory experiments. Initially, the effect of fluid temperature on the ablation of a vertical ice wall is investigated. At the low temperatures and oceanic salinities that our experiments were conducted at, the temperature at the ice-fluid interface will be below 0 degrees Celsius and the interface salinity will be non-zero. Because of this, it is useful to consider a driving temperature defined as the difference between the fluid temperature and the freezing point at the fluid salinity. It is shown that the ablation rate increases like the driving temperature to the 4/3 power, while the interface temperature increases almost linearly with the driving temperature. Ablation of an ice wall releases cold fresh water that rises up the ice face as a turbulent plume. This turbulent plume enhances the transport of heat and salt to the ice-fluid interface and helps to maintain ablation of the ice. The properties of the plume are investigated in detail and a model is developed that describes them. The ocean around Antarctica and Greenland is generally stably stratified in salinity. The effect of stratification is investigated to examine the potential sensitivity of the ice sheets to changes in ambient fluid stratification. Regimes are found where small changes in the strength of stratification can lead to large changes in the ablation rate and the plume properties. This result highlights the possibility that weakening stratification, not just warming oceans, could lead to increased mass loss from the ice sheets. In many locations around Greenland, plumes of freshwater are released at the base of the glacier. These subglacial plumes are modelled in the laboratory by releasing a two-dimensional freshwater plume at the base of the ice face. The additional source of buoyancy typically leads to significantly higher ablation rates and plume velocities, consistent with past numerical and observational studies. These laboratory experiments represent an increasingly realistic model of the ice shelves around Antarctica and Greenland. Despite important physical processes still being excluded, the experiments present a useful and previously unavailable dataset with which numerical models can be tested and oceanographic field observations can be compared

Annual and diurnal water vapor cycles at Curiosity from observations and column modeling

Local column precipitable water contents (PWC) for more than a martian year from 113 Curiosity ChemCam passive-mode sky scans were used to force a column model with subsurface adsorption. ChemCam volume mixing ratios (vmr) and T, RH and vmr from REMS-H were compared with model results. The REMS-H observations point to decrease of vmr (i.e. depletion of near-surface water vapor) during every evening and night throughout the year. The model's pre-dawn results are quite similar to the REMS-H observations, if adsorption is allowed. The indicated porosity is about 30% and the night depletion ratio about 0.25. If adsorption is not allowed, RH and vmr become excessive during every night at all seasons, leading to ground frost between Ls 82 degrees-146 degrees; frost has not been observed. As brine formation is unlikely along the Curiosity track, adsorption thus appears to be the depleting process. During daytime the ChemCam vmr is in general close to surface values from the Mars Climate Database (MCD) vmr profiles for the Curiosity site when those profiles are scaled to match the ChemCam PWC. Our simulated daytime surface-vmr is in turn close to the ChemCam vmr when moisture is assumed well-mixed to high altitudes, whereas a low moist layer (15 km) leads to overestimates, which are worse during the warm season. Increased TES-like regional PWC also leads to large overestimates of daytime surface-vmr. Hence the crater appears to be drier than the region surrounding Gale and the results support a seasonally varying vertical distribution of moisture with a dry lower atmosphere (by Hadley circulation), as suggested by MCD and other GCM experiments.Peer reviewe

Data assimilation insights on selecting the most valuable atmospheric measurements

We discuss how objective guidance on selecting the most valuable atmospheric measurements on future Mars spacecraft missions can be provided through already developed Martian atmospheric data assimilation systems, and in particular through Observing System Simulation Experiments (OSSEs) which are widely used to design instruments for the Earth’s atmosphere

Testing a common ice-ocean parameterization with laboratoryexperiments

Numerical models of ice-ocean interactions typically rely upon a parameterization for the transport of heat and salt to the ice face that has not been satisfactorily validated by observational or experimental data. We compare laboratory experiments of ice-saltwater interactions to a common numerical parameterization and find a significant disagreement in the dependence of the melt rate on the fluid velocity. We suggest a resolution to this disagreement based on a theoretical analysis of the boundary layer next to a vertical heated plate, which results in a threshold fluid velocity of approximately 4 cm/s at driving temperatures between 0.5 and math formulaC, above which the form of the parameterization should be valid.We gratefully acknowledge the technical assistance of B. Tranter, T. Beasley, and A. Rummery, and the financial support of the Australian Research Council Discovery grant DP120102772