Carbon Neutral Green Energy Aviation

Aircraft noise seems to generate more complaints than other sources of noise pollution that are just as loud.  This complex dilemma is investigated by Inderjit Singh, Aviation analyst and the Head of Aviation at the URS Corporation’s South Asia office, ICAO Consultant and the former Airport Chief Executive of Indira Gandhi International Airport.
In the current global climate change situation, the ultimate aim for any industry must be sustainable development, and aviation is no exception.  And though the aviation industry is widely perceived as being one of the most polluting, the fact remains that according to the Intergovernmental Panel on Climate Change (IPCC) of the UN, aviation contributes just 2% of the global carbon emissions.
Of particular interest is how aviation’s influence on emissions is overblown at nearly every level.  For instance, the global consumption of aviation gasoline and jet fuel accounts for 3,284,000 barrels per day, while petroleum products are produced at a rate of 41,176,000 barrels per day, meaning aviation only accounts for about 12% of the total.  This doesn’t mean the aviation industry is oblivious to emission problems.  It is still vigorously developing innovative technologies and solutions to control and further mitigate any ill effects it creates; thereby enabling future generations to continue benefiting from air travel.

Aviation Outlook
As an engine of commerce and social interaction – transporting people and goods rapidly and safely on diverse missions all over the world – it is clearly in everyone’s interest that the aviation industry grows and prospers as its environmental impacts are reduced.
The aerospace industry has started to tackle this formidable task and has already made significant efforts to reduce its environmental footprint (see article on page 32).  With global air traffic growing at an average rate per annum of 4-5%, and the ever-increasing propensity to travel by air, environmental concerns are gaining in importance.  Technological and operational improvements are imperative to outweigh the impact of traffic growth.  Engine performance has been greatly enhanced and produced dramatic reductions in noise and emissions.  Though individual aircraft have progressively become quieter and cleaner, the rapidly increasing demand for aviation services has mandated more aircraft and more flights.  So the total environmental consequences have increased and become more apparent.  Simultaneously, the public awareness of environmental issues and the political pressures to resolve them have also risen dramatically.  Consequently the pressure on aircraft designers, operators and the builders of new airport facilities to recognise environmental considerations has never been higher.
The world’s governments are actively pursuing through the aegis of the United Nations Framework Convention on Climate Change (UNFCC) and the International Civil Aviation Organization (ICAO) plans to mitigate the contribution of pollution caused by aviation to climate change.  Although international aviation is currently excluded from the Kyoto Protocol, its contribution to global warming is predicted to increase by 2050 due to the industry’s rapid growth and the simultaneous development of alternate energy-efficient technologies in other sectors.  Europe’s Flightpath 2050 programme, which sets out the continent’s research goals, officially supports the Air Transport Action Group’s (ATAG’s) target of reaching carbon-neutral growth in 2020 and reducing aviation’s overall CO2 emissions by half between 2005 and 2050.

Environmental Issues and Mitigation Measures
Traditionally, the two main environmental issues generally associated with aviation are noise and emissions and within the emissions domain, lately the distinction is made between local air quality and climate change.
Aircraft noise levels today are typically around 20 db lower than they were 40 years ago.  It is a significant achievement in view of considerable increased engine thrust power; consequent to the larger aircraft size and the increased payload.  The majority of European airports currently have their night time operations restricted and even night curfews are imposed due to noise-related issues.  Many airports in South Asia have implemented noise-related penalty charges and may soon emulate their European counterparts in restricting air transport activities.
The number of airports affected worldwide is likely to increase further during the next decade, despite all the technological advancements.  This is predominantly due to how airports, as centres of business and economic growth, inevitably attract adjacent housing developments.  In recent years, many Greenfield airports have conspicuously been planned and developed away from the cities, along the coast or off-shore.  However, the opposite is also true and major commercial and residential infrastructure developments are being planned in the close vicinity of certain airports.  This is part of the so-called Aerotropolis concept, which defeats what should be the prime objective of taking airports away from human habitation.  It is an interesting subject and worthy of a major debate and an analysis in itself.
Local Air Quality is increasingly becoming a matter of major concern and a key driver in the technical evaluation of airport rehabilitation programmes.  Air pollutants such as Nitrogen Oxides (NO2 and NO) and particulate matter (PM); has led to air transport been identified as a prime contributor to local air quality problems.  Exposure to particulate matter can lead to health hazards ranging from minor effects on the respiratory system to premature death.  At some of the busiest airports, NO2 levels have already exceeded the annual limit set for ambient air quality.  Some airports in Europe and UK have imposed airport emissions charges and the likelihood of other busy airports following suit in the future cannot be ruled out.
The provision of additional runways at existing airports to solve long-term capacity issues have become a huge target for criticism.  It is increasingly stressed that international aviation, like all other transport sectors, should be integrated into the global emissions reduction targets to ensure it contributes to reducing greenhouse gas (GHG) emissions and does not undermine efforts to address climate change.  Including aviation in the EU Emissions Trading Scheme (ETS) is a key – but hugely controversial – step in the direction of meeting this goal.
Alternative fuels will, over a period of time, become a major driver in reaching the objective of carbon-neutral growth for aviation.  Drop-in biofuels – those that are entirely compatible with conventional fuels – have been successfully tested and are already in use on certain commercial routes.  The industry aims to replace 6% of current fossil fuel with biofuels by 2020.  Beyond the complex issue of life-cycle assessment, the major challenge will be the logistics to ensure that biofuels are available in a reliable quantity and cost-effective manner to air operators worldwide.

Green Airports
Contemporary airports, some the size of townships, are increasingly intent on becoming carbon neutral, as the bill for energy consumption in conventionally-designed airports is about 48-50% of their annual costs.  The airport’s passenger and cargo terminals are being planned and developed with appropriate ‘green’ building materials, within the scope of atmospheric conditions, in an attempt to achieve near-zero carbon footprints.  Their vast operational areas are designed and maintained with measures to incorporate ‘green’ technologies that will minimise pollution and can lead to energy savings of around 30-35%.  Green terminal buildings and airports can burn less energy and consume fewer resources by using as many local materials as possible during the construction period.  The perception that green building costs more is somewhat misconceived as the life cycle cost of such facilities is much lower than for conventional structures.  Furthermore, there are several tax incentives to the LEED and Energy Star Certified airport projects making them more cost effective with reduced operational costs.
Airport Operations & Environment Compatibility
Air traffic movement patterns ie: the approaches, take-offs and obstacles – both natural and man-made – have the most significant influence on an airport’s land use planning, which in turn has a direct bearing on the environment.  The basic objective of land use planning in the vicinity of airports is to maximise the compatibility of the airport and its environs within the constraints imposed by other operational and local planning considerations and regulatory bye-laws.  It seeks to shield the community from the adverse effects of airport operations and so protect the large public investment in the airport by ensuring that operations and further development are not constrained or prevented by the high environmental costs that can result from inappropriate land use.
In the diagram at Figure 1, I have attempted to capture all the essential elements that contribute to the creation of green airports and their relationship with the environment.  The flow diagram is indicative of the steps to be taken to ensure use of local materials, efficient and energy-saving designs, star rating (energy efficient) machinery, equipment and airport systems, recycling of water, rain water harvesting and other such measures to design and build a true green airport.
Fig.1 Issues related to Green Airports and their relationships with the Environment

The Last Word
My ‘take’ on aviation and the environment is that as we look at the future of aircraft and airports, we should be equally committed to looking at the future of the environment.
The author will be pleased to interact with readers via and/or debate on the issue in an aviation forum.