“Come on, stop calling us polluters.” That was the shocking message of denial from the head of the International Air Transport Association at a summit that took place this month as it emerged that rising numbers of passengers are shunning flights because of the climate emergency. Consumers are voting with their feet. Too many perhaps for barely profitable airlines, but too few to shift the corporate inertia surrounding an environmental crisis. The trend may accelerate as planetary disaster unfolds. The industry needs a better strategy than burying its head in the sand.

With ice sheets vanishing from the roof of the world and fjords disappearing in the North Atlantic, Big Air must first accept the scale of the problem. Aviation needs to be part of the global commitment to phase out fossil fuels and limit catastrophic temperature rises. Industry emissions are growing faster than original forecasts. This year, for the first time, global aviation emissions passed the one gigatonnes of CO₂ mark. The industry contributes about 3% of annual global emissions but could be a 10th or more of the total by 2050. The second step needed is a radical new plan that goes far beyond the current Carbon Offsetting and Reduction Scheme for International Aviation. This scheme only covers 75% of the industry, and experts calculate that a significant reduction of emissions from flying will be needed by 2030 to keep warming below 2C.

Although there’s been a buzz about electric planes, they cannot provide all the answers. Replacing fuel tanks with heavier batteries would not make sense for long flights. Even if some travellers are thinking again, passenger growth outpaces the drop in carbon emissions from greener technology. That is not to say cleaner fuels are not needed. It’s just that such innovation won’t be enough on its own. The demand for air travel needs to be damped.

This is easier than one might imagine. Frequent flying is a minority sport: 75% of all flights in the United Kingdom come from 15% of the population. It is the better-off who can afford to fly all year round. They are behind the 40% rise in holiday flights in the last decade – an astonishing 11m extra trips.

To get a feel of the civilisation-wide significance of climate change, think about this fact: a UK resident making a single transatlantic round trip emits as much CO₂ as they would in two months of everyday life. To change passenger behaviour might need taxation. A recently leaked EU report suggested that increasing the cost of jet fuel tax by 10% would cut the number of travellers by a similar amount. There might be a case for the first trip or two in a year to be lightly taxed and for subsequent ones to face steeply rising levies.

If the UK government was serious about the climate emergency it would think again about a third runway at Heathrow. Pressing ahead with it, or any runway, would make a mockery of Theresa May’s promise to reach net-zero emissions by the middle of this century. The government’s climate advisers said we could hit that target and still be flying in 2050. The aviation sector, they calculated, would account for 31 megatonnes of CO₂. If a third runway at Heathrow goes ahead that will shoot past 40 megatonnes of CO₂. The polluter ought to pay. The cost of absorbing the equivalent of airline emissions should be raised to make airport expansion less attractive. Although MPs did vote for the third runway, in a few years’ time the transport secretary will have a chance to block Heathrow’s proposals. To save the planet, whoever is in the post should do so.