If one invention in mankind's history has connected people and places, helped raise the standard of living for billions of people, and allowed anyone to travel the world freely, it is the modern jet airliner. Yet environmental activists are now sprouting another offshoot of the "global warming" movement to recklessly contract and diminish this advancement in human ingenuity because they fret over aircraft as one of the most "carbon-intensive" forms of travel.

Your new word for the day is "flygskam" (pronounced: "fleeg-skam"). It is a Swedish word introduced by the nascent — still mostly European — environmental movement to "flight-shame" travelers into refraining from taking flights to lower carbon emissions.

Among the most notable to embrace the flygskam idea so far is the 16-year-old Swedish climate activist Greta Thunberg. It was Thunberg who traveled to New York this summer to address a U.N. climate summit via her 15-day trans-Atlantic sailboat passage instead of hopping on an airplane to make the likely less than 15-hour door-to-door trip. The idea was originally backed by Olympic athlete Bjorn Ferry and gained momentum after Thunberg's mother, opera singer Malena Ernman, publicly announced she would stop flying, with other Swedish celebrities following suit.

Also in Europe, where the movement is still trying to get off the ground, there is even related activism, complete with its own word "tagskryt" (roughly translating to "train bragging"), where one boasts about taking trains instead of planes. (Europeans don't often travel the 2,500 air miles from New York to L.A., or the even farther 2,700-plus miles from Seattle to Miami — and stay within the same country. Stockholm-to-Helsinki or London-to-Paris-to-Berlin just isn't the same.)

Understandably, the flygskam movement has hit rough air trying to catch on in the United States despite increasing notoriety in Europe. In fact, air travel here rose 3.9% in the first five months of 2019 (while decreasing by a comparable percentage in Sweden) and global forecasts for air travel continue to rise according to the International Air Transport Association (IATA). That said, while few Americans have actually heard of the European "flight shame" movement, a North American strain is already emerging. One can already draw similarities and parallels to flygskam from American politicians — Democrats in particular — with their proposals for some sort of "Green New Deal" having more urgent and radical iterations that could drastically alter today's expectations and ability to fly by air.

As with any human activity, flying comes with environmental costs, but these must be tallied with cost-benefit "common sense" ("sunt förnuft" in Swedish).

Airlines themselves are paradoxically textbook examples that clarify why flygskam is overreach. Airlines already well understand that it is in their own best interest to limit and reduce fuel consumption (and thus exhaust emissions), irrespective of any flygskam activism. Quite simply, fuel is expensive to carry and burn. Fuel vies with labor as airlines' biggest expense, and companies work extremely hard to find ways to reduce consumption and improve overall fuel efficiency. Burning fuel costs money and affects their bottom line. Airlines have made an exacting science of conserving fuel and burning as little as possible for each and every flight, from short "hops" to long-haul trans-global routes. Yet it is their business — it is their livelihood — to accommodate and move all the passengers who need and want to travel by air. There is no flygskam to be found in that goal to provide such a valuable service to their "customer" — the flying and traveling public.

Further, aircraft exhaust emissions and fuel efficiency can be only two of many vital considerations. A modern airliner must also be able to operate safely, make less noise, withstand tremendous weather and aerodynamic forces, have sufficient size to carry many passengers over long distances at high speeds, and dependably fly regularly with reasonable operating costs. Within these parameters, U.S. domestic airlines will carry well over 800 million passengers annually, generate revenues exceeding $187 billion per year, employ some 700,000 people worldwide, and contribute approximately five percent of annual U.S. gross domestic product (GDP).

The world's two largest aircraft-makers — Boeing and Airbus — have put into service many fuel-efficient planes (e.g., models of the B-787 and A-350) designed for long-haul international routes capable of fuel efficiencies rivaling a compact car for moving each passenger a comparable distance. Engine-manufacturers, in turn, solved reliability issues so airliners can now safely fly long oceanic routes with two engines versus previous standards for three or four. Fuel-efficient "high bypass turbofan" engines are the norm, superseding earlier far less fuel efficient "turbojet" engines.

According to the trade organization Airlines for America, fuel efficiency has improved more than 125 percent since 1978. That amounts to 4.6 billion metric tons of carbon dioxide eliminated — equivalent to about 25 million cars taken off the road annually. This has occurred even as more people choose to fly. In 2016, domestic airlines, working with the U.S. government and its global partners, agreed to an even more aspirational goal of achieving a 50 percent net reduction in carbon dioxide emissions from 2005 levels by 2050.

Airlines are also working in other areas to improve fuel efficiency and halt emissions growth. Among their initiatives are developing alternative fuels; refining both airport ground and flight operations; and better managing air traffic, while grounding and retiring older, less fuel efficient aircraft. Pilots are also trained and directed to fly flight profiles that maximize fuel efficiency. Fuel loads for each route are precisely calculated because of those costs to carry unneeded fuel, while airlines carefully monitor excess seat capacity to optimize transporting passengers on fewer flights.

Finally, flight safety is at least as important as environmental concerns. Commercial air travel is the safest form of intercity transportation in the United States. Numbers tell the story; driving is more dangerous. There are between 30,000 and 35,000 motor vehicle fatalities, along with some six million reported auto accidents, every year in the United States, compared with, on average, three commercial aviation deaths. Train travel, while safer than automobiles, is still only the second-safest option, with the safest option being flying.

No one anywhere in the world should feel any flygskam, second thoughts, or guilt over his decision to travel to his chosen destination by air today — or tomorrow. All the given rationale for air travel should be even more compelling to a mobile population patronizing an industry with a proven record of acting responsibly without unwarranted intervention by anyone, whether it be by government or activists now trying to "shame" people for flying. Such misplaced activism as the European "flygskam" movement should never be given "clearance for take-off" in the United States.

Colonel Chris J. Krisinger, USAF (ret.) served in policy advisory positions at the Pentagon and twice at the Department of State. He was also a National Defense Fellow at Harvard University. As a military aviator, he piloted C-130 "Hercules" transport aircraft. He has family members employed in the airline industry. Contact him at: cjkrisinger@gmail.com.