Climate change is the most important global concern of the time since life on earth, as we have known it, is being radically affected by the increase in average global temperature. This crucial issue necessarily puts pressure on every industry, and especially in aviation. Many of us have in mind a general image of airplanes, since apparently effortless, fly at extraordinary speeds carrying lots of people and their baggage for very long distances. What we usually forget is that in order to accomplish the task, they consume vast quantities of fossil fuels that are released every day into the sky, contributing dangerously to the warming of the planet. But on the other hand, the first global climate action framework from any transport sector industry was presented in 2008 by the aviation industry, which has been working since then to limit their environmental impact in the short term.
Emission of aircraft engines could be very similar to any other kind of emissions produced by the combustion of fossil fuels, but the most important difference is that almost all of them are released at high altitudes. As stated in different studies, the CO2 and other greenhouse gases emitted in the ground by fossil fueled vehicles, remain in the atmosphere for centuries causing a warming effect. However, more powerful increases are caused by gases released by planes at high elevations, for instance, vapor trails and ozone, since those chemicals catalyze a number of reactions and atmospheric effects.
According to the International Civil Aviation Organization (ICAO), aviation global CO2 emissions are about 2% of total (724 million tones of CO2 were generated in 2014), and about 12% of the CO2 emitted from all transportation sources. From the total aviation emissions, 65% are from international and 35% for domestic flights. But carbon dioxide is not the only greenhouse gas emitted; nitrogen oxides, sulphur oxides, ozone, unburned hydrocarbons and carbon monoxide are also exhausted by aircraft engines. Seeing that passenger and cargo air transportation are predicted to grow more than two times the levels of 2004 before 2020, the Intergovernmental Panel on Climate Change (IPCC) says that aviation share on global CO2 emissions will increase to more than 5% by 2050 (a worst-case scenario says 15%), due to the increasing demand from passengers, especially in emerging markets.
What is the aviation industry doing to limit its impact?
Working together on actions intended to reduce aviation emissions is a joint effort of the whole sector, including aircraft and engine manufacturers, air traffic managers, airports and airlines. Given the economic size of the industry and the importance of the contribution to the global effort of getting on the 2°C path, there are basically four main topics of action aviation is focusing on:
Innovation in technology
New planes are generally 25% more efficient in fuel terms than previous one, and the planned investment in this matter for the next ten years will be more than $1 trillion. Additionally, aircraft and engine producers spend more than $15 billion yearly on efficiency research. In terms of fuel efficiency standards, a long term initiative will lead to predictable progress, for instance, the use of alternative fuels that have been tested on small scale (such as biomass or waste), which have the potential to cut almost 80% of emissions, compared to actual fuels. Lighter materials used in the construction of aircraft and changes in aerodynamic designs reduce the total weight and drag, a generally improve fuel efficiency. For instance, according to Airbus, A320 airplanes are 40% less expensive to operate than the previous model.
More efficient traffic control operations have great potential for saving emissions. These could include better traffic management procedures, reducing on-board equipment weight, using optimal ranges for aircraft trips, connecting airplanes directly to electricity sources in the ground while they are parked. For example, an in-flight method for landing called “continuous descent” flight paths, saves more than 140 kg of CO2 per trip.
Reducing delays, shortening of flying times, controls on air traffic zones, building common air space among countries, military no- fly zones negotiations, satellite based traffic control (NextGen in the case of U.S.), are a few examples of changes that could effectively contribute to the reduction of Greenhouse Gas emissions. A good example is the design of alternative flying routes that can reduce distance and travel times, that if shortened just by one minute, could save at least 100 kg of CO2.
More efficient technology and operations will take time to achieve emission targets. Economic measures need to be part of the strategy, and taxation of aviation fuel implemented through international agreements has the potential to incentivize more investment. Global measures need to focus on the internalization of carbon pollution ensuring that passengers are not taxed on multiple levels.