If your company is in business to make money (as pretty much all companies are), how likely are you to launch a huge marketing campaign begging people not to use your product? Probably not very likely. Unless you're KLM Royal Dutch Airlines, in which case you've already done it.

That's right. KLM, the Netherlands' national airline, just launched a campaign called "Fly Responsibly" in which it makes a surprising request of its customers: Fly less. "Do you always have to meet face-to-face?" the promotional video asks. "Could you take the train instead?"

Wait, what? An airline is asking its passengers not to fly? Yes. Because, as KLM explains in an accompanying statement, air travel accounts for 2 to 3 percent of manmade CO2 emissions worldwide and that number is growing, as more people in more countries are climbing out of poverty and hankering to see the world. The 100-year-old airline says it's been doing its part. In an accompanying statement, KLM says it has been replacing its fleet with more fuel-efficient planes, using sustainable fuel, and has even created a sustainable fuel plant in the Netherlands. "We work hard to get things right, but all parties involved need to join forces to create a sustainable future."

Some critics say this amounts to nothing more than "greenwashing." After all, the airline still offers special deals and its website invites people to "Book a flight with KLM and visit the most incredible destinations around the world." And indeed, in the accompanying statement, the airline explains that it won't stop promoting air travel--after all it wants to stay in business "for our customers and for our 33,000 employees."

No carbon tax, please.

Interestingly, the airline also notes in its statement that it's opposed to a national carbon tax in the Netherlands since, it claims, passengers would simply drive to Germany or Belgium and fly from there instead. Therefore, KLM says, a carbon tax on aviation should only be imposed if it can be imposed globally--which is pretty disingenuous, because of course that'll never happen. It also claims that a tax that isn't invested back into the aviation industry to make it more sustainable "won't do anything to combat climate change." This, again, is untrue because the main point of a carbon tax is to make polluting more expensive, which causes people and companies to do less of it.

All this talk about a carbon tax can give you a big clue as to KLM's true motivation here. A carbon tax or cap-and-trade law seems like a non-starter in the U.S.--even in the very blue state of Washington, one was roundly defeated last election. But in Europe, the idea is very much alive. France's huge "yellow vest" demonstrations began as opposition to a planned carbon tax that working people felt they couldn't afford. (It was withdrawn.) But in the Netherlands, a carbon tax which would increase the price of airline tickets among many other things is in the works. My guess is that KLM hopes that by getting out ahead on this issue, it can push the government toward letting companies take voluntary action rather than writing new laws.

KLM also says that as part of its sustainability effort it's sharing information about sustainability with other airlines, beginning in September with a webinar with its sustainable fuel supplier, SkyNRG. Which sounds good, but since SkyNRG is in the business of selling its fuel, the webinar may amount to a big sales pitch. Perhaps more useful, though, KLM says it's exploring connections with trains. That's a great idea, because for a lot of passengers, transferring to a train rather than a connecting flight to go a relatively short distance will be appealing, and environmentalists believe short airplane trips in particular can and should be replaced with other forms of transportation. KLM has also been inviting passengers to pay a small extra fee that the airline will use to offset their flight and make their travel carbon neutral. It will share that system with other airlines as well.