Bethan Owen

Flying into the Future: Aviation Emissions Scenarios to 2050

This study describes the methodology and results for calculating future global aviation emissions of carbon dioxide and oxides of nitrogen from air traffic under four of the IPCC/SRES (Intergovernmental Panel on Climate Change/Special Report on Emissions Scenarios) marker scenarios: A1B, A2, B1, and B2. In addition, a mitigation scenario has been calculated for the B1 scenario, requiring rapid and significant technology development and transition. A global model of aircraft movements and emissions (FAST) was used to calculate fuel use and emissions to 2050 with a further outlook to 2100. The aviation emission scenarios presented are designed to interpret the SRES and have been developed to aid in the quantification of the climate change impacts of aviation. Demand projections are made for each scenario, determined by SRES economic growth factors and the SRES storylines. Technology trends are examined in detail and developed for each scenario providing plausible projections for fuel efficiency and emissions control technology appropriate to the individual SRES storylines. The technology trends that are applied are calculated from bottom-up inventory calculations and industry technology trends and targets. Future emissions of carbon dioxide are projected to grow between 2000 and 2050 by a factor in the range of 2.0 and 3.6 depending on the scenario. Emissions of oxides of nitrogen associated with aviation over the same period are projected to grow by between a factor of 1.2 and 2.7.

Prediction of total oxides of nitrogen and nitrogen dioxide concentrations in a large urban area using a new generation urban scale dispersion model with integral chemistry model

Abstract This paper describes the use of urban emission inventory data and an urban scale dispersion model (ADMS-Urban) to calculate concentrations of NOx and NO2 in London. The dispersion model used in this study is a second generation Gaussian dispersion model which is characterised by the use of boundary layer similarity profiles to parameterise the variation of turbulence with height within the boundary layer. The model has an integral chemistry model which is used to predict concentrations of nitrogen dioxide and ozone. The paper examines the performance of the integrated modelling system to predict concentrations from emission sources in Greater London. Predictions have been compared with observed data at four locations, two locations in Central London and two in East London. Predicted concentrations for a summer and winter period have been calculated and modelled and measured times series data have been compared. Statistical analyses have been carried out to assist in the comparison of model predictions with monitored data. Although no absolute significance can be attached to the numerical values of these measures, taken cumulatively, some conclusions regarding the emissions inventory data and the models’ performance can be made. The applicability of the model of atmospheric chemistry used in this study to calculate the concentrations of nitrogen dioxide is appraised and a comparison has been made with concentrations of nitrogen dioxide predicted from oxides of nitrogen using empirical relationships.

Identifying the contribution of different airport related sources to local urban air quality

The Air Quality Strategy and part IV of The Environment Act, within the United Kingdom, highlight the need for local authorities to undertake air quality assessments. Many UK local authorities have recently completed a review and assessment of local air quality, which has culminated in the declaration of Air Quality Management Areas (AQMAs) in many urban areas, where air pollution objectives are likely to be exceeded. Those local authorities who declare AQMAs are required to undertake a further stage of assessment, which involves the determination of the contribution of various sources of air pollution, such as airports. Many studies of this nature only consider an airport as one source, however, this study considers the impact of different airport related sources on local air quality from a dispersion modelling study of a large urban area. This paper describes the methodology, results and draws conclusions from a study that assesses the impact of a regional airports sources (such as its contribution from road traffic and aircraft). The paper also considers the effect of modelling the above ground aircraft emissions sources (climbout and approach) to different altitude heights. The papers results highlight the need to investigate the source contributions of an airport, to local air quality, as opposed to considering an airport as just one source.

Use of a new generation urban scale dispersion model to estimate the concentration of oxides of nitrogen and sulphur dioxide in a large urban area

This paper describes the use of urban emission inventory data and an urban scale dispersion model (ADMS-Urban) to calculate concentrations of NOx and SO2, in two areas of London, Central London and East London. Local authorities in the UK are expected to undertake reviews of air quality in their areas to determine whether air quality objectives set by the National Air Quality Strategy will be achieved by 2005. The UK Government proposes that local authorities in urban areas develop spatially disaggregated emission inventories in conjunction with dispersion models to assess compliance with the air quality objectives laid down in the strategy. This paper examines the performance of an urban emission inventory and a dispersion model (ADMS-Urban) to assess air quality from emission sources by comparing model predictions with monitored concentrations at four locations. The model used has a GIS interface and uses a spatially disaggregated urban emissions inventory to provide an integrated emission inventory and dispersion modelling system. The dispersion model used in this study is a second-generation Gaussian dispersion model which is characterised by the use of boundary layer similarity profiles to parameterise the variation of turbulence with height within the boundary layer. In a large urban area such as London there are many different sources contributing to the concentrations in the atmosphere. This modelling study aims to examine and evaluate the consideration of both local effects and emissions from the Greater London region. The emissions inventory data for the study are described by a 1×1 km grid covering the Greater London Area which measures 60 km east to west and 45 km north to south. Predicted concentrations for a summer and winter period have been calculated and modelled and measured times series data have been compared. Statistical analyses have been carried out to assist in the comparison of model predictions with monitored data. Although no absolute significance can be attached to the numerical values of these measures, taken cumulatively, some conclusions regarding the emissions inventory data and the model performance can be made.

A methodology for estimation of vehicle emissions in an urban environment: an example from Greater Manchester

Road transport is a major contributor to urban air pollution. The introduction of local air qua lity management in the UK will require objective test procedures to evaluate and prioritise the air pollution benefits of existing transport systems and proposed developments. This methodology has been developed to assist the land use and transport planning professionals in evaluating current and potential future impacts on air quality. The method couples an emissions estimation procedure to a traffic flow database. It requires data on emission factors, the composition of the vehicle fleet, vehicle control technologies and the daily traffic flow profile. With these data, it is possible to generate emission estimates per kilometre, link or road as selected by the user. Forecasts can be made by varying input variables. The current methodology allows prediction of five or more pollutant species/classes, limited only by availability of emission factors. The method utilises a commercially available personal computer based spreadsheet. Further coupling of the method to a geographical information system will improve the decision support capability of the method.

Air Quality Management - a challenge for large international airports?

Air transport worldwide is expected to grow by 5-6 % a year between 1997 and 2010. Worldwide this growth will translate into more than 3 billion passenger movements per annum by 2010 who will travel to and from airports by a range of transportation modes. The industry is expanding to meet the needs and expectations of an increasingly mobile and affluent society. Paradoxically, this predicted expansion will take place during a period, when in response to scientific and medical evidence, national and international governments are likely to enact stringent air quality standards and guidelines at the local, national and international level. This paper reviews the impacts that the aviation industry will have on local air quality using case studies of Manchester and London Heathrow airports. In particular the paper examines whether the industry is positioned to react proactively and positively to the air quality challenge and maintain the predicted growth trend or whether the industry must adopt a capacity limit dictated by its ability to meet new air quality standards.

Air quality management at European airports

Airports are dynamic economic enterprises which are also sources of air pollution. The success of airport air quality management will in part enable the ambitious development plans of the industry to be realised. This paper considers the current state of air quality management at European airports and the future of air quality assessment and management. It examines the technical pressures and management structures and processes for air quality management and considers the future evolution of these issues within Europe.