When Brazilian aviator Alberto Santos-Dumont first flew his boxy “14-bis” heavier-than-air flying device in 1906, the environmental effects of air travel were the furthest thing from his mind. With the event being the world’s first public demonstration of manned flight, the focus was on wonder, accomplishment, and the power of creative thinking. But despite their undeniable importance to our day-to-day lives, one can’t help but ask, how do airplanes affect the environment?
Airplanes affect the environment through emissions as they burn fossil fuels to release carbon dioxide, carbon monoxide, and nitrogen oxides. These pollutants destroy the ozone layer and lead to the trapping of solar radiation at ground level, effectively increasing the chances of climate change.
The process of trapped radiation heating up the planet is commonly known as the greenhouse effect. Both jet and propeller engines used on airplanes contribute to this effect through emissions.
Let us take a closer look at how airplanes affect the environment.
Specific Environmental Effects of Different Emissions
Environmentalists normally point to carbon dioxide (CO2) as the “big bugaboo” of planetary peril for all mankind. Without question, it does contribute to the greenhouse effect. But as mentioned, CO2 is not the only culprit our environment faces.
Nitrogen Dioxide
Nitrogen dioxide is a natural by-product of burned fossil fuel. Its color ranges from reddish-brown above 70°F (21°C) to yellowish-brown below 70° F (21°C). Since airplanes burn fossil fuel, they emit nitrogen dioxide into the atmosphere, which, in excess amounts, produces consequences such as:
- Acid rain
- Smog
- Decreased or stunted plant life
Most nitrogen dioxide produced by airplanes comes during take-off and landing. Indeed, over the past ten years, Environmental Protection UK found nitrogen dioxide to be the main pollutant of concern around airports.
Sulphur Dioxide
Another way airplanes affect the environment is through the emission of sulphur dioxide, a by-product of burned fossil fuel. If you’ve ever smelled a burned match, then you’re familiar with this chemical compound. When combined in large quantities with water and air, the chemical compound can produce acidic rain that is harmful to both humans and plant life. Secondary particles from sulphur dioxide, called sulphates, have been known to cause haze around major airports all over the globe.
Particulate Matter
Particulate matter—or PM—differs from harmful atmospheric gasses in that it is heterogeneous. Or simply put, PM does not mix fluidly with its environment but exists as a separate entity.
Examples of particulate matter include dust, smoke, and soot. These are examples of PMs we can see with the naked eye. However, the case is not always so cut and dry, as some PM is actually microscopic, which means people, animals, plants, and water are absorbing these toxins passively all the time.
As particulate matter released from airplanes settles on the Earth’s surface, it can damage plant life or even prohibit new plants from growing healthily. PM also makes the air less breathable for wildlife. Indeed, microscopic PM can cause severe health problems when inhaled. These health problems range from asthma to cancer.
Volatile Organic Compounds
Besides the emission of particulate matter, airplanes affect the environment by releasing volatile organic compounds (VOCs) into the environment. VOCs are chemicals that vaporise quickly at room temperature.
Everyday experience with VOCs comes with the use of products such as perfume, cologne, floor cleaners, and pumping gas. If it’s a chemical that you can smell, that chemical is emitting VOCs.
To reduce the adverse effects of VOCs, proper ventilation is key. When painting a room, you leave the windows open for fresh air. The same goes for polishing your fancy parquet floors. Inhaling vaporised chemicals is at best annoying; at worst, they can trigger major allergic reactions or cause prolonged respiratory illness.
Nitrogen dioxide and sulphur dioxide are both considered VOCs. For airplanes, the primary suspect for VOCs lies with unburned hydrocarbons. Incomplete combustion of fuel releases carbon monoxide into the air.
Compounding the issue, VOC emissions from an aircraft are more prominent while the craft is at cruising altitude rather than take-off and landing. This means the effects are taking place over much longer time periods.
Carbon monoxide contributes to the greenhouse effect covered earlier in this article. Even worse, you can’t smell carbon monoxide, you can’t see it, and you can’t taste it. It does its work incognito. The good news is that carbon monoxide doesn’t typically occur at high levels out of doors, except near internal combustion engines.
The above illustrates ways that airplanes affect the environment. I realise it’s all a bit depressing to think about. But take heart because airlines are by no means turning a blind eye to the problems.
What Are Airlines Doing About the Issues?
Whether airlines have begun to feel guilty about their carbon footprints on the environment or they just want climate scientists to stop barking at the hangar door, it’s evident they’re taking the necessary steps to make air travel more friendly for the planet. Promises from the higher-ups at Delta, United, and JetBlue are encouraging, but the task is not an easy one.
Alternative Fuel
The primary focus is on jet fuel. How can it be made to emit fewer—or even zero—harmful by-products into the air? Turns out there are safer, alternative compounds that can be mixed with traditional jet fuel for a cleaner burn—cleaner, but not perfect. These compounds are referred to as “drop-ins.”
Not every airline has its chips bet on drop-ins. Some are exploring the use of hydrogen instead, which burns into clean water vapour. The problem with this technology is that it’s a long way off being viable.
Make-Ups or Offsets
For some airlines, the best way to respond to the unending debate on how airplanes affect the environment is by making up for their faults or contributions to the problem.
While make-ups do not exactly solve the problem, they play a somewhat crucial role in mitigating the effects of large-scale pollution.
For instance, some institutions are big on planting trees, funding research, and investing in a wide range of green causes.
Electric Flight
Finally, we have the concept of battery-powered airplanes. An electric airplane eliminates the carbon footprint left by an engine-powered craft. Noise pollution also becomes a thing of the past, as these planes are almost completely silent.
Have a look at this video and be impressed:
The problem with electric flight is that, for commercial purposes, the technology is still a long way off. The batteries are too large and heavy for planes to carry them for very long on a proper charge. But as the video demonstrates, some of the smaller planes can fly up to 500 miles on a single charge. It may only be a matter of time before a major breakthrough occurs.
Final Thoughts
The airline industry has long been under the microscope for negative effects on the environment. The Environmental Protection Agency has even cracked down on the sector by implementing international standards for fuel efficiency and lower carbon emissions.
But rather than protest, many airlines have capitulated with exciting solutions to the problem while at the same time investing in better things still. It would seem that everyone involved is on the same page and wishes to contribute to a cleaner, safer world to live in.
