[A]lthough fuel prices have climbed steadily for the last quarter century, the jet fumes we spew into the skies are heavily subsidised.
That's because, unlike other types of fuel, airlines don't pay tax, apart from GST, on the aviation fuel they use on international routes.
It is legally exempt because of a 1944 global agreement.
The agreement is the Chicago Convention on International Civil Aviation, but it doesn't require countries to exempt fuel they sell from tax. Instead, it requires that fuel on board planes and not unloaded not be subject to tax or duty (which is both convenient and sensible). But according to a 2012 UK parliament report, it became common practice to exempt aviation fuel to encourage the growth of air travel.
This isn't just unfair - airlines should pay their way, just like everybody else - its also stupid. Exempting jet fuel from carbon taxes or the ETS means airlines have no financial incentive to find lower-emissions fuels or alternative technologies. Which means the only way we can reduce emissions from them is reducing flights. There's already a "no fly" movement from those concerned about climate change, and reducing your air travel is being pitched as one of the most effective things you can personally do to save the climate. That's only likely to grow stronger as the climate crisis bites. And the tax exemption pushes us down that path rather than alternatives.
Like the internet, and not dying of plague, cheap and easy air travel is one of the great miracles of our age. It brings the world closer together, and that's a Good Thing. But this shortsighted policy means we are being forced to choose between that, and destroying the planet. And that's no choice at all.