Reducing Greenhouse Gas Emissions in the Aviation Industry

In the past decade, there has been a rapid growth in the demand for air travel and, as this demand grows, so does the quantity of greenhouse gas emissions. By 2050, the total amount of greenhouse gas emissions produced each year is expected to quadruple. According to the Center for Climate and Energy Solutions (C2ES), 1.5% of greenhouse gas emissions per year are caused by the aviation industry. The United States accounts for about 40% of the aviation-caused greenhouse gas emissions. Rather than working to reduce the total amount of greenhouse gas emissions, the industry is focusing on just reducing the rate at which the emissions produced is increasing. According to C2ES, using a combination of improving aircraft efficiency and improving operational efficiency would reduce the rate at which emissions are produced by 50% by the year 2050.[1]

In aviation history, the evolution from using wood, to aluminum and fiberglass, to carbon composites in aircraft structures illustrates the desire for more lightweight materials to be used in the aviation industry. Ultra-lightweight materials and structures enable aircraft to carry more fuel and payload. Such improvements could result in lower operation costs because of better fuel efficiency. According to Boeing, fuel consumption accounts for about 23% of the cost of operating an airplane. Using lighter materials will improve performance, which will provide for lower operating costs. For example, in the design of the Boeing 787 Dreamliner, composite materials made up 50% of the structure.[2] These composites are lighter, more durable, and reduce the overall cost of operation due to reduced scheduled maintenance.

CaptureAs more airplanes spend more time in the air, they will burn more fuel. In addition to seeking alternative fuels and improving aircraft structures and aerodynamics, why not just reduce the amount of time airplanes spend in the air? The Federal Aviation Administration (FAA) is implementing a new program, Next Generation Air Traffic Control (NextGen), which began in 2004 and is set to be complete by 2025. This is a program which facilitates the transition between ground-based radar to satellite-based GPS. This improvement in technology in the air traffic control system aims to reduce airport congestion and produce fuel savings along with other environmental benefits. By using GPS technology, air traffic congestion can significantly be reduced. For example, Instead of using a conventional approach where an airplane is instructed by Air Traffic Control (ATC) to level off at various stages in the descent, a more practical constant descent approach would be used. Using this strategy, airplanes will be able to descend to an airport with almost entirely idle engines instead of using high amounts of power to maintain several different altitudes using a conventional descent. In addition to an improved descent profile, the time in air will be decreased using more logical and direct routes using GPS technology compared to traditional radio navigation. The amount of time to fully transition to the NextGen program is quite large but the effects are already noticeable on regional levels. For example, this type of technology has saved $20 million in fuel and has increased takeoffs and landings by 10% at Atlanta’s Hartsfield-Jackson International Airport. Using a cost of about $5.00 per gallon for jet fuel, this program has saved 4 million gallons of fuel while increasing airport operations.[3]

The reality of the aviation industry is that air travel will only increase in the years to come. By using a combination of a variety of methods, such as improved aircraft structures and operational efficiency, the rate at which greenhouse gas emissions are created can significantly be reduced. These benefits come at quite a cost and it will take years to notice the effects of the changes. For example, in order to purchase new and improved aircraft, airlines must first retire all their old fleets before implementing new ones and this can take decades. In addition, the cost and time it takes to fully integrate programs like NextGen into the ATC system is quite high at an initial estimate of $40 billion and 20 years to complete[3] but the long-term effects will be noticeable by only doubling greenhouse gas emissions instead of quadrupling it by the year 2050.

References

  1. Center for Climate and Energy Solutions, Aviation Factsheet.
  2. D. Chong, Nanotechnology for aerospace applications: the potential, 2009.
  3. W. Jackson, What's keeping FAA's NextGen air traffic control on the runway?, 2013.

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