I haven't flown for six years. I didn't feel a pressing need to travel, but most of all I didn't want to make such an enormous contribution to climate change. A return flight from Melbourne to London pumps about 1.8 tonnes of carbon pollution into the atmosphere, wiping out other efforts to reduce emissions at home.
For a roving freelance journalist, it was a principled but ridiculous stance. I once spent two days on buses between Adelaide, Melbourne and Sydney just to conduct a few face-to-face interviews. My most impractical assignment was researching the Queensland sugar industry — two days on a train, then a taxi into the cane fields around Bundaberg.
But now here I am on a Jetstar flight to Sydney for a climate change conference. As the plane takes off, I squirm with a sense of hypocrisy: I've broken my vow for the same reason I made it.
Returning to something after a long absence brings fresh insight, so I spend the entire trip pondering why we fly, and why it's so hard to give up. The answers are less obvious than they first appear.
There's the convenience, of course. We slingshot ourselves from one place to another in order to get there more quickly.
But even that's more complicated than it seems. Once everyone has access to the same conveniences, they congeal into cultural norms. You're expected to fly at a moment's notice for work or a family crisis, and refusing to do so can leave you unemployed or ostracised. This social and cultural pressure is rarely acknowledged.
Watching paddocks pass underneath as the plane crosses northern Victoria, I can think of another compelling reason we fly. The status. Flying makes us feel important, as the language we use to talk about it reveals.
Cognitive linguist George Lakoff argues that we think in terms of metaphors. By metaphor he doesn't mean rhetorical flourishes that catch our eye because they are unusual or poetic. He means phrases so familiar we don't notice them.
"One of the reasons sustainability lacks appeal is it's described as a down concept. We're asked to reduce our emissions or live a low-impact lifestyle ... Refusing to fly takes this heresy to its extreme: here is someone literally renouncing the high-life."
His book Metaphors We Live By mentions the orientational metaphor up-down. We use these concepts with remarkable consistency. For example, happy is up and sad is down. So we say 'that boosted my spirits', 'you give me a