KLM is telling people to fly less and think about taking the train instead in its latest campaign.

A few years ago, this might have seemed counterintuitive for a company whose business is all about air travel. But as worries over the environmental impact of flying increase, the Dutch airline is taking the initiative to do something about it. This week it published an open letter in newspapers including the New York Times, Washington Post, The Guardian and the Sunday Times from its CEO Pieter Elbers, calling for global action by both passengers and the aviation industry on sustainable travel. 

The open letter is accompanied by a social video, which asks a series of questions including: "Do you always have to meet face-to-face," "Could you take the train instead," and "Could you contribute by compensating your CO2 emissions or packing lightly?"

The video is part of an online platform with the tagline and logo "Fly Responsibly," which will run across all KLM communication. It was created by agency DDB Unlimited in Amsterdam. 

“KLM has strong views on creating a sustainable future for aviation," said Esther te Pas, managing director at DDB Unlimited in a statement. "So, it’s very fulfilling to turn this vision into the ‘Fly Responsibly’ platform. This isn’t about a campaign, but an initiative with a long-term commitment to change. We’re proud to take the lead and to help KLM to really set the agenda on sustainable air travel.”