KLM is already among the world’s more fuel efficient airlines, according to the International Council on Clean Transportation (pdf), due in part to its cabin layout. Airlines with more business- and first-class seats, for instance, have a greater carbon footprint, relative to the number of people they are able to transport.

Environmentally conscious customers, especially in Europe, are increasingly opting out of flying, which contributes about 2.5% of global emissions. (Few personal actions are quite so harmful for the environment.) They may be following in the footsteps of climate campaigners such as Greta Thunberg: The Swedish teenager and activist will only travel by rail or bus, and is considering taking a cargo ship to attend the UN’s special climate change meeting in New York in September.

At the same time, governments across Europe are pressuring airlines to be more accountable: The French government recently called for EU executives to end a global tax exemption for jet fuel to reduce air travel and, in turn, emissions. Lawmakers have also previously proposed banning short domestic and international flight routes, which are often only marginally quicker than high-speed trains.

Of course, KLM isn’t planning to hang up its flying goggles just yet. “It is our business and we want to stay in business,” it said, in a statement following Elbers’ letter. “We are stepping up to speed up progress towards a sustainable future, but we are a company that needs to make profit to survive and to continue to invest in sustainable solutions. We want to still be around when we have succeeded in our efforts to make aviation sustainable.”

Some Dutch politicians have already dismissed the campaign as simple greenwashing. For now, the airline is only offering gentle encouragement to fly less, and has not imposed more drastic solutions, such as making its carbon-offsetting scheme compulsory for consumers, or reducing its short-haul legs.

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