I knew it was a bad idea to press the button, but I just couldn’t help myself. I had just finished booking flights to the UK and was excited by the prospect of visiting my family whilst trying to convince myself that air travel was irrelevant to climate change. The “Calculate  your carbon emissions” button that appeared on the website after having paid for the flights, threatened to bring me back to reality and wreck my excitement, but as my hand hovered over the mouse I knew there was no escaping the facts.

It’s not that I am unaware of the impact, it’s just that I have gotten quite good at justifying my personal air travel to myself and others, and know all the regular excuses by heart –

1. It’s a form of public transport. Aren’t we all encouraged to take public transport?
2. I’m travelling to see family and everyone is entitled to see their family whenever they want.
3. Everyone else travels by plane, so why shouldn’t I?
4. If I (and my husband and three kids) weren’t travelling, there would be empty seats on the plane.
5. We travel lightly, with only two cases between the five of us. Most people take far more luggage than that.
6. Airlines need revenue to develop carbon-neutral travel options for the future.

So I braced myself and clicked the button. After hoping for a response of “Good news, the carbon emissions for this journey will be zero, as you will be travelling on the first ever solar-powered (and utterly safe) flight”, I soon learnt I would be responsible for 2.94 tonnes of carbon dioxide emission. As a family of five this was 14.71 tonnes. I reduced my guilt slightly by computing different scenarios and discovered that first-class passengers are responsible for twice as much CO2. But 14.71 tonnes still seemed a hefty blow to my self-image of being an environmentally-friendly person.

I could endlessly replay the regular excuses to myself or I could take up the airline’s kind offer of allowing me to offset my emissions for $64AUD. A happy tax? A guilt tax? A carbon tax? I had searched for the cheapest flights, so am I so much of a mug to voluntarily pay extra?  Or was $64AUD a small fee to feel better about myself? I have never considered offsetting emissions before as I didn’t understand what it was all about and my gut feeling was that it was just another revenue earner for airlines. What I hadn’t understood was that carbon offsets are used to fund real and specific projects and don’t just land up in unknown coffers. Such projects include protecting rainforests from logging, building wind farms in Taiwan and providing communities in rural China with modern and efficient household stoves to replace their current coal-powered inefficient and polluting stoves.  If I had endless time on my hands I could check these projects more thoroughly and set about doing a full independent investigation. But if I had enough time to do that I may as well just walk and sail to the other side of the world.   Perhaps I leave by cynicism behind and just trust their claims.