Delta is one of America's 100 most sustainable companies – No. 27, to be precise – and the No. 1 U.S. airline, according to an in-depth Barron's study that rated 1,000 companies in five key categories: shareholders, employees, customers, environment and community.

Barron's, an influential business publication that covers finance and markets, relied on Calvert Research and Management to devise the study's methodology and create the final list after rating the largest publicly held companies in the United States. Read the methodology.

"The fact that you emerged as one of the top companies on that list is an indication that your organization is one of the leaders in incorporating environmental, social and corporate governance factors into all the work you do," the president of Calvert's parent company wrote in an email to Delta CEO Ed Bastian this week.

Calvert CEO John Streur said financial markets are recognizing that sustainable practices are good business and, increasingly, corporate responsibility is a stakeholder expectation.

"Companies can be differentiated based on how well they manage their environmental and social impact, and the strength of their governance," Streur said in a Barron's article. "The list shows who's creating a better company, long term, for long-term investors."

"Our core mission at Delta is to bring people together and connect the world, and it is an honor to be recognized by Barron's for our efforts," said Bastian. "Our commitment to be a responsible corporate citizen is driven by our people, who work every day to help make the world a better place. We will continue to challenge ourselves to better serve the world in every way we can."

Some highlights of Delta's social responsibility and sustainability efforts:​

• Giving back 1 percent of Delta's net income from the previous year to charitable organizations, as well as, for the first time in 2019, paying all 80,000+ employees to spend a day of service to their communities.
• Expanding its leadership in the fight against human trafficking, with enhanced employee training and community partnerships.
• Accelerating environmental sustainability efforts by replacing hundreds of aircraft over the next five years with more fuel efficient A321s, A220s and Boeing 737-900ERs.
• Continuing its voluntary commitment to carbon-neutral growth by purchasing almost 12 million carbon offsets since 2012.
• Achieving and maintaining employee gender pay equity at 100 percent.
• Sharing $1.3 billion in profits with employees, more than any other U.S. company.
• Being named on the FTSE4Good Index for four consecutive years, included in the Dow Jones Sustainability North America Index for eight consecutive years and given an honorable mention in Fast Company's 2019 World Changing Ideas Awards. 

Read more in Delta's most recent Corporate Responsibility Report.