The 6 Most Sustainable Airlines for Flying Green

Written by Lydia Noyes


Lydia Noyes

Climate Journalist

Lydia Noyes is an organic farmer and climate journalist. She is a member of the USC Annenberg Center for Health Journalism.


Your penchant for travel is partly to blame for putting the environment in peril. Commercial flying accounts for about 3% of global carbon emissions, and that percentage is likely to increase as more people turn to the skies for travel.

But while passenger numbers are growing by 5% each year, airlines have succeeded in keeping their emission percentages to approximately half of that. This is due to a combination of more efficient planes, better biofuel alternatives, and other concentrated efforts to burn less jet fuel. 

However, some airlines are fighting harder against climate change than others. They are taking strides to shrink or offset their carbon footprint by investing in environmentally sustainable projects around the world. Fly with them, and you’re supporting their efforts for a healthier planet. 

Below, we’ve ranked the six most sustainable airlines that fly out of two major US airports: LAX and JFK. Each stands out within the industry for its policies towards environmental protection and fuel efficiency, and we believe each one is a smart choice for your travel needs. 

Just keep in mind that the best thing you can do for the planet is to reduce your flying altogether, so consider carefully whether there are more environmentally sensitive ways to get to your destination. 


KLM Royal Dutch Airlines

Leaf Score

Highlights: KLM wins our top spot for its across-the-board commitment to improving its environmental impact—even going so far as to attempt to convince potential customers to avoid flying when possible.

Since 2008, KLM‘s climate action plan has ensured that the airline is more sustainable in the sky and on the ground. The company’s Carbon Reduction Roadmap has a set goal of reducing its total carbon footprint by 15% in 2030 compared to 2005 levels. In fact, KLM has landed in the top three of the ‘Airlines’ category of the Dow Jones Sustainability Index for the past 15 years.

KLM also participated in an industry-wide goal for 2020 to reduce emissions through better fuel efficiency, smarter in-plane technology, and the use of renewable biofuels. This includes practices like “water washing” planes in flight to keep temperatures down and powering its hub airport in Amsterdam 100% on sustainable fuel sources. 

The company started developing sustainable fuel options in 2009, completed its first commercial flight with biofuel in 2011, and launched the Corporate Biofuel Programme in 2012. Today, the company uses 57 times more biofuel than it did in 2011 and is seeking out ways to increase this amount. One method is building the first sustainable aviation fuel plant in the Netherlands, which will run on organic waste streams that include used cooking oil.

Perhaps most notably, the airline has launched a “Fly Responsibly” campaign focused on educating its customers about some of the planet-friendly alternatives they should consider instead of taking a flight, including trains or hosting business meetings virtually. This makes KLM one of the only airlines willing to encourage potential customers not to give them business when it’s a better option for the planet.  

KLM also allows you to pay a small premium when you book your flight, representing your portion of CO2 emissions. This money enters the CO2ZERO fund, where it pays for the protection and replanting of tropical forests around the world.  


Alaska Airlines

Leaf Score

Highlights: Beyond funding green research projects and earning acclaim as one of the most efficient airlines globally, Alaska airlines is making sustainability commitments from the airline kitchens on up.

This Pacific Northwest airline has gone public with its promises to lower CO2 emissions and limit other environmental damage. As one of the world’s most fuel-efficient airlines, Alaska Airlines has ranked as the leading U.S. airline on the Dow Jones Sustainability Index for three years running.

The airline is maximizing fuel efficiency by using split scimitar winglets that save an estimated 34,000 gallons of fuel per aircraft per year. It also pioneered a navigation technology known as RNP, which leads to more direct flying and saves 1.2 million gallons annually. These have led to a 16% reduction in emissions compared to 2012 levels. 

Alaska Airlines is also making strides with sustainable fuel by partnering with the Port of Seattle and Boeing for a Greener Skies program that contributes to environmentally-friendly research projects. This research program has led to innovations in landing techniques, noise pollution, and fuel usage. It has the goal to someday power all flights from the Seattle-Tacoma International Airport with biofuel.  

Likewise, the airline made history in 2017 when it became the first in the world to fly two commercial flights from a biofuel made from the stumps and branches wasted after a timber harvest.  

On the small side, Alaska Airlines has reduced its reliance on paper products by 50%, stopped serving straws, and now composts coffee grounds from in-flight beverages, resulting in over 14 tons of composted coffee per year. The airline currently composts other food waste in 12 flight kitchens as well. 


Xiamen Airlines

Leaf Score

Highlights: This airline wins acclaim for committing to dozens of projects focused on environmentally sustainable flying and for publicly supporting the U.N.’s Sustainable Development Goals.

Xiamen is a Chinese-based airline that became the first to publicly align itself with the United Nations Sustainable Development Goals for environmental protection. 

The airline draws attention to these commitments through a series of themed flights celebrating the earth’s biodiversity through themed meals, souvenirs, and theme-specific in-flight entertainment. The end goals are to both bring awareness and inspire passengers to make environmentally sustainable changes in their own lives. 

On a technical level, Xiamen Airlines implemented 70 programs focused on energy conservation and fuel efficiency in 2019. These include flying with only the precise amount of drinking water needed for passengers, a dynamic cost index to choose the optimal flight speed for fuel use, frequent engine cleanings to boost efficiency, and more. These measures lead to a savings of 110,000 tons over 2019, equivalent to cutting 346,000 tons of carbon emissions.


Cathay Pacific

Leaf Score

Highlights: Cathay Pacific has reduced its share of greenhouse gas emissions through a carbon offset program, flying with biofuels, incorporating plant-based meals on its airline menu, and other sustainability measures.

With a goal of becoming the “world’s best airline,” this Hong Kong airline has an impressive environmental policy. 

The airline is also making strides towards sustainability by adding six new fuel-efficient Airbus A350s to its fleet. It also plans to use biofuel on its planes, which should allow up to an 80% savings on traditional fuel use. Overall, the airline estimates its fuel efficiency efforts have led to a more than 28% improvement in fuel efficiency since 1998.  

Cathay Pacific has gone paperless within its cockpits by transitioning to apps instead, saving thousands of tons of carbon emissions from manufacturing. They have also set a target to reduce single-use plastic use by 2022, effectively removing 200 million pieces of single-use plastic from its yearly operations.

Regarding inflight meals, Cathay Pacific plans to become the world’s first airline to serve OmniPork, a plant-based pork alternative with a smaller carbon footprint. It is also collaborating with alternative meat supplier Green Monday to develop more meat-free meals. 

Like KLM’s CO2ZERO program, Cathay Pacific allows passengers to offset their carbon emissions from flying through a “Fly Greener” program. This program, which launched in 2007, lets you purchase carbon offsets for your flight, and the money goes to fund third-party projects that offset carbon emissions. 


Delta Air Lines

Leaf Score

Highlights: Delta has dedicated itself to canceling out half of its fuel emissions by 2050, as well as smaller measures such as removing or recycling the majority of single-use materials on its flights and supporting carbon offset programs for customers.

This American airline has long been a leader for environmental activism. 

Starting in March of 2020, Delta committed to putting $1 billion over the next ten years into its efforts towards canceling out all its fossil fuel emissions—both in the air and on the ground. These investments will involve projects that advance clean air technologies, reduce carbon emissions, and develop new projects that better mitigate emission waste. 

The company has set short and long-term goals to improve fuel efficiency and reduce carbon emissions by 50 percent by 2050, compared to 2005 levels. On a smaller scale, Delta has partnered with Looptworks to upcycle more than 350,000 pounds of textiles from recycled employee uniforms.  

Delta was the first U.S. airline to recycle cans, bottles, cups, newspapers, and other single-use products on flights, and has recycled more than three million pounds of aluminum to date. It is in the process of removing all single-use plastic from flights, which will eliminate over 300,000 pounds of plastic per year. 

As with many others on this list, Delta has long invested in carbon offsets, which totaled over $2.5 million for 2017 alone. In 2019, the company purchased 50,000 carbon offsets, which offset the emissions involved in flying over 300,000 people. Customers have the option to help offset their own travel pollution by buying carbon offsets online, which are then used to support programs that offset or sequester carbon emissions.  


American Airlines

Leaf Score

Highlights: By investing in modern aircrafts that focus on fuel efficiency, American Airlines is one of the better flying options for reducing carbon emissions—especially if you support its Cool Effect partnership.

American Airlines has earned a reputation for investing in modern upgrades that have led to a more environmentally conscious flying experience for customers. As with many airlines, it has made a series of small-scale upgrades, including adding winglets to the plane’s wing ends, adopting paperless cabins, and reducing each aircraft’s weight for better flight efficiency. 

Other moves towards sustainability include investing in more fuel-efficient aircrafts and committing to adopting more sustainable aviation fuels as they become available. It has added 500 new planes since 2013, earning it the position of youngest U.S. fleet. This included 50 new Airbus A321XLR aircrafts known for their fuel-efficient “narrowbody” design, which replaced the airline’s aging and less efficient 767s.  

The airline has partnered with Cool Effect to connect customers with a way to offset the carbon emissions associated with their flight. This nonprofit organization seeks out quality carbon reduction projects around the world and sponsors their efforts. 

Looking forward, American Airlines has set a goal to cut its carbon emissions in half over the next 30 years. This also includes committing to sourcing 2.5 million gigajoules of energy (the equivalent of 20 million gallons of fuel) from renewable sources by 2025. To date, the airline is powering itself on electricity from 100% renewable sources at its headquarters in the Dallas-Fort Worth International Airport. 


In closing, the best move for the planet is to fly less. That’s why Greta Thurnberg sails on a carbon neutral boat rather than flying to NYC for climate meetings. However, if you have to fly, and you’re flying out of our major American airports, the airlines I’ve listed here are making a good faith effort to fight the rising threat of climate change.

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