Lynnette Dray

Technology limits for reducing EU transport sector CO2 emissions.

Using a new data set describing the techno-economic characteristics of current and projected future transport technologies and a synthesis of existing transport demand models, lifecycle CO(2) emissions from 27 EU countries (EU27) were estimated in the absence and presence of new policy interventions to 2050. Future CO(2) emissions are strongly dependent on geographical scope and economic growth assumptions, and to a lesser extent on uncertainties in technology characteristics, but in the absence of new policy intervention they continue to rise from present-day values in all three scenarios examined. Consequently, EU27 emissions goals, which may require a 60% decrease in transport sector greenhouse gas emissions from year-1990 values by 2050, will be difficult to meet. This is even the case under widespread adoption of the most promising technologies for all modes, due primarily to limitations in biofuel production capacity and a lack of technologies that would drastically reduce CO(2) emissions from heavy trucks and intercontinental aviation.

Mitigation of Aviation Emissions of Carbon Dioxide: Analysis for Europe

This paper investigates the interaction between economic, technological, and operational measures intended to reduce air transport-related emissions of carbon dioxide (CO2). In particular, the introduction of aviation to the European Union Emissions Trading Scheme (ETS) in 2012 may prompt increased uptake of presently available options for emission reduction (e.g., retrofitting winglets, expanding maintenance programs) by airlines operating in Europe. Carbon prices may also determine the use of options currently under development [e.g., open-rotor engines, second-generation biofuels, and improved air traffic management (ATM)]. The results of a several studies analyzing airline costs and emission reductions that are possible from different mitigation options are applied to a systems model of European aviation. With a set of nine scenarios (three internally consistent projections for future population, gross domestic product, oil and carbon prices, each run with three policy cases), technology uptake and the resulting effect on fuel life cycle CO2 emissions with and without an ETS are analyzed. Some options are rapidly taken up under all scenarios (e.g., improved ATM), others are taken up more slowly by specific aircraft classes depending on the scenario (e.g., biofuels), and others have negligible impact in the cases studied. High uptake of one mitigation option may also reduce the uptake of other options. European aviation fuel life cycle emissions could be reduced below 2005 levels before 2050 if cellulosic biomass fuels are made available by 2020. However, the land use requirements in this scenario may limit its practicality at currently projected cellulosic biomass yields.

Modelling Airline Network Routing and Scheduling under Airport Capacity Constraints

A flight routing and scheduling model is under development that predicts airline routing and scheduling under airport capacity constraints. It consists of several components describing different aspects of the air transport system, including passenger demand, airline competition, flight delay, and airline cost. These models are integrated into a flight routing and scheduling model in which an objective function is defined to maximize airline system profit within a routing network, subject to constraints. This framework allows the relationships between fares, passenger demand, infrastructure capacity constraints, flight delays, flight frequencies, and routing network to be simulated. In this paper the integrated flight routing and scheduling model is first applied to a series of simple theoretical routing networks to illustrate its capabilities. With increasing airport capacity constraints the results show an increase in average fares, a decrease in O-D passenger demand, and a shift in flight routing away from the most constrained airports. The model is then applied to a network of airports in the United States with 2005 population, income and airport capacity inputs. With further development the model is to be applied to forecasting air traffic system growth, including network and schedule changes resulting from increasing delays, in the Aviation Integrated Modelling (AIM) project under development at the University of Cambridge. Copyright

Modelling Environmental and Economic Impacts of Aviation: Introducing the Aviation Integrated Modelling Project

The Aviation Integrated Modelling project is developing a policy assessment capability to enable comprehensive analyses of aviation, environment and economic interactions at local and global levels. It contains a set of inter-linked modules of the key elements relevant to this goal. These include models for aircraft/engine technologies, air transport demand, airport activity and airspace operations, all coupled to global climate, local environment and economic impact blocks. A major benefit of the integrated system architecture is the ability to model data flow and feedback between the modules. Policy assessment can be conducted by imposing policy effects on the upstream modules and following implications through the downstream modules to the output metrics, which can then be compared to a baseline case. A case study involving different evolution scenarios of the US air transportation system from 2000 to 2030 is used to show the importance of feedback and to model a sample policy scenario in order to illustrate current capabilities.

Network and environmental impacts of passenger and airline response to cost and delay

* † ‡† * *† § The Aviation Integrated Model is a policy assessment tool designed to simulate the operation and economic/environmental effects of local and world airline networks over the next 30-50 years within a modular framework. Feedback between demand, capacity, air traffic delays and policy measures is a key part of this model. For example, unconstrained model projections of US air transportation system growth with no passenger, airline or policy response included show average arrival delays of over two hours at major US airports in 2030, a condition that is unlikely to materialize. A more likely situation is that a combination of responses act to bring the air transport system to a new equilibrium at which higher fares, extra capacity or increased operational efficiency reduces the delays to a more acceptable level. Similarly, the application of policies designed to mitigate some of the environmental impacts of air transportation will also alter the system equilibrium state. In this paper we use the Aviation Integrated Model to systematically examine these feedback effects, concentrating specifically on the passenger response to increases in travel time, airfare, and policy responses to environmental concerns. We contrast the reference case in which the main feedback effect is passenger and airline response to air traffic delay with sample policy scenarios.

A Comparison of Aviation Greenhouse Gas Emission Mitigation Policies for Europe

This paper integrates the results of a set of studies looking at UK and European aviation environmental policy measures. It uses a model of the European air transport system to assess the economic costs and environmental benefits associated with proposed emission mitigation strategies. In particular, we con centrate on the potential penetration of fuelsaving technologies and operations, lower carbon alternative fuels and high-speed rail in response to the European Union Emissions Trading Scheme, and the effect on CO2 emissions that this has in both the UK and Europe. A special emphasis is placed on the interaction effects of multiple mitigation policies. We find that a combination of policies could potentially allow UK and European lifecycle aviation CO2 emissions in 2050 to be reduced to below year-2005 levels. Although other operational and technological measures can reduce aviation CO2 emissions by up to 15% compared to an unconstrained base case, the largest part of this reduction comes from the interaction between carbon trading and cellulosic biomass fuels.