Flying has always felt like magic: step inside a metal tube, lift through clouds, arrive somewhere entirely different. But the magic has a cost – one the industry has long encouraged us not to look at too closely.

Aviation accounts for around 2.5% of global CO2 emissions, and roughly 4% of human-driven warming once other climate effects are included. The United Nations warns that without intervention, those emissions could triple by 2050. Yet the impact of flying is far from evenly shared. Just 1% of the world's population is responsible for more than half of all passenger aviation emissions, while most people never board a plane at all.

Few sectors highlight the disparity in emissions more starkly than private aviation. One recent study found that the United States alone produces 55% of the world's private jet emissions, and private flights have surged since the Covid-19 pandemic, rising nearly 50% since 2019. At the same time, expansion continues: London's Gatwick Airport, for instance, was recently cleared to build a second runway, enabling up to 100,000 additional flights each year.

Those competing realities are now shaping international climate negotiations. Last June, eight countries, including France, Spain, Kenya and Barbados, launched a Premium Flyers Solidarity Coalition that aims to introduce a levy on private jets, first- and business-class air travellers to ensure that those who fly most contribute proportionally more to climate adaptation and loss-and-damage funding.

"It's about rebalancing towards climate and tax justice," said Friederike Roder, Director of the Secretariat for the Global Solidarity Levies Task Force, the international body that's responsible for supporting and coordinating the coalition's development. "While everyday car drivers pay heavy fuel taxes, kerosene on international flights has remained largely untaxed for historic reasons. Aviation just isn't providing its fair share. This is a first step to change that."

With COP30 currently taking place in Brazil, the coalition is starting formal negotiations and working to expand membership, potentially paving the way for the first global tax on luxury flying.

Yet the future of aviation isn't only being written at climate summits. It's also unfolding in cockpits, crew rooms and engineering hangars, as insiders quietly reassess what it means to fly in a warming world.

One such insider is Todd Smith, a former Senior First Officer for Thomas Cook. Smith left commercial flying in 2020 after a gradual shift in how he perceived his beloved industry – a shift that began with a moment of uneasy wonder during a trip to Peru in 2018.

Smith had travelled to the Andes to see Rainbow Mountain, a ridge of striking mineral colours at nearly 5,000m (16,404ft). The site had only recently started attracting visitors after the glacier that once covered it melted due to rising temperatures. Standing among hundreds of tourists on the trail, he realised the beauty he was witnessing was the direct result of global warming. "Up until then, I hadn't even heard the term 'climate crisis'," he said. "That experience changed me."

Feeling that aviation was becoming "morally compromised", Smith began studying climate science........

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