Exploring how the airline industry is ironically affected by the very environmental phenomenon it contributes to.

The airline industry has seen solid growth in recent years. The industry increased passenger traffic growth by about 5% from 2014 to 2015 and although there might be some signs of a slight downward shift in passenger growth, IATA’s Air Passenger Market Analysis notes “the global passenger market has made a robust start to 2016” [1].

Airlines have recently started paying attention to the effects of climate variability on their operations. When a plane is in flight, it emits greenhouse gases that contribute substantially to increased global temperatures known as global warming.  As a consequence, climate changes impact the airline industry by resulting in longer flight times due to changes in weather patterns leading to more emissions and this perpetuates a dangerous feedback loop. Long story short, the irony is real in the airline industry when it comes to climate change!


According to a study published in the Nature Climate Change journal, climate change has caused a shift in wind patterns by accelerating the jet stream (aka winds flowing from west to east). In this study, the authors evaluated flight time data on three transatlantic flights on four major carriers (including Delta Airlines) over an 18-year period. The major finding from this study was the year over year variability in flight times on those routes where 88% of the variability was due to the El Nino Southern Oscillation and the Arctic Oscillation [2], both climate phenomena! The study goes on to explore the difference between westbound and eastbound flights, pointing out an inverse relationship between westbound and eastbound flight times. In other words, when the jet stream is accelerated, eastbound flights are shorter while westbound flights are longer due to headwinds. However, the shorter eastbound flight times don’t necessarily offset longer westbound flight times so the net effect is still negative. For example, you might have a shorter flight from Honolulu to Los Angeles but that return flight to Honolulu will be longer.


Delta Airlines is one of the world’s largest global airlines and operates more than 15,000 flights per day in conjunction with its transatlantic joint ventures [3]. Adding a layer of possible climate change effects amplifies the variability in their current operations.


A flight travelling from the UK to NYC will undoubtedly experience a lot of bumps in the air due to the fact that it is westbound and facing headwinds. This means no “free time” to walk around the cabin because that seat belt sign will stay on. Increased turbulence in the air also disrupts the in-flight services while causing possible injury to crew and passengers. This could mean limited snack service and increased customer complaints to Delta.

Flight times

Remember earlier when I said you might have a shorter trip from Honolulu to Los Angeles, but a longer return flight time? Well that’s no good for Delta. Longer flight times means potential flight delays which creates a major headache for the network and operations groups. Moreover, Delta might miss their on-time arrivals/departures, impacting performance metrics. Late arrivals or departures could have a ripple effect on their competitors’ operations as well.


Increased flight times equals more fuel needed and fuel used. This ultimately means Delta might have to shell out a lot more money for fuel on their transatlantic flights. High fuel costs could lead to a hike in airfares which will make customers unhappy.


Delta Airlines is dedicated to conducting its operations in a way that minimizes impact on the environment, by partnering up with programs like The Nature Conservancy that “strives to stop deforestation and promote alternative energy” [4]. Delta is implementing internal and external strategies to reduce its carbon footprint to mitigate its contribution to climate change that ultimately negatively impacts its operations. Internally, Delta is improving fuel efficiency across its mainline fleet of about 800 aircraft. This will decrease fuel burned which reduces emissions and overall fuel expenses. Fuel efficiency also influences Delta’s aircraft purchasing decisions. The company aims to buy aircrafts that are designed to use lower amounts of fuel.  On the external front, Delta fosters transparency and accountability by asking its customers to use their carbon calculator which basically helps them see how much carbon was emitted on any given flight. Additional actions include emissions verification CDP and reporting carbon emissions to the EU Emissions and EPA Reporting organizations.

In addition to Delta’s commitment to reducing fuel emissions, I think Delta should study wind patterns in more depth to develop a better understanding of the shifts and associated variability so that they can structure their transatlantic operations around it.

(772 words)


[1] Air Passenger Market Analysis, May 2016

[2] Coupling between air travel and climate

[3] Delta Financial and Operating Performance, October 2016

[4] Delta Corporate Responsibility



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  1. While it’s encouraging to see that Delta is taking a number of internal and external measures to reduce its carbon footprint, I would like to see the data on the savings vs. the potential unintentional negative impact these initiatives may have on the environment. For example, with a more fuel-efficient fleet, does that translate into an operational strategy whereby Delta opts to expand the number of flights and routes undertaken by each plane to capitalize on the fuel savings? Moreover, do initiatives such the carbon calculator actually impact consumer behavior? Or are they simply marketing tactics to prop up the perception of Delta as environmentally-conscious?

  2. Lady, you did a great job of bringing me up to speed on the impact of changing wind patterns, an issue I’d never even considered for airliners (despite the amount of time I spent on a plane in my former life as a consultant). I’ve heard a lot about airliners pushing for a higher percentage of filled seats on flights, largely driven by an effort to decrease variable passenger costs, but also having the side effect of decreasing per passenger emissions. One of the areas that I’m really curious about is the impact of more fuel efficient planes, such as the Boeing Dreamliner, on airliner efficiency and climate impact. These planes have the ability to dramatically increase air travel efficiency, and I hope that airliners continue to invest in efficient airplanes for efficiency purposes, even as the cost impact has decreased due to lower oil prices.

  3. Very interesting article – I learned a lot. For instance, I did not know that westbound flight were becoming longer than eastbound are getting shorter. Generally I wonder how the share of adjustment and innovation will split between aircraft OEMs and operators. What is likely certain is that air travel is on the critical path of growth, so solution are to be found.

    I measured how much can be done by the Operator. The wind pattern is certainly very interesting. Generally computing power may become of even greater use for understanding meteorological patterns in high atmosphere.

    But some long term solutions are likely to involve OEMs. For instance, I wonder if the altitude could not be optmized again with either planes going higher up and have more like rocket trajectory or on the contrary like during the 20th century and the WW, planes flying very low on water to benefit from the ground effect like soviets Ekranoplanes (a word I treasure), such as the A-90 Orlyonok.

    However the most exciting thing would be to have Concord-like planes with a Delta-shaped wind flying for Delta Airlines!

  4. The longer flight times will lead to significant operational challenges across the network, as we have seen in our United case. I wonder how much buffer is added to the flight schedules at the moment to prepare for the potential longer time in the air as you explain above. It is also difficult to gradually increase the flight time as customers remember how long their route normally takes.
    Regulating emissions from airlines is a significant challenge that global regulation should address. Hopefully we are making progress:

  5. Lady, thanks for this interesting piece on Delta. Reading your post, I was curious just how big airlines’ relative contribution to greenhouse gas emissions – and aviation is huge. I did a bit more reading, and discovered that in fact, emissions from aviation could account for the whole 2 degree rise in the world’s temperature, which is the threshold provided by the United Nations [1].

    While I agree that studying the increased variability as a result of changes in air traffic patterns would be a smart move for Delta, I would also be concerned about the impact that low-cost carriers are having on air travel prices overall driving this uptick in demand. You mentioned passenger volume increased 5% from 2014 to 2015, which is remarkable. Delta has launched their own low-cost service offering and so have many other full service US airlines, such as American Airlines. I’d argue that while the decrease in prices is good for the consumer, it is bad for the environment as people are more likely to make a decision to fly somewhere instead of alternate transportation. I think Delta needs to dig in and understand how they can incentivize consumer behavior in a way that helps minimize their fuel consumption – perhaps offering miles rewards for consumers to change flights if a flight is empty or improved pricing for more fuel effective planes.


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