Pulling Carbon Offset Figures Out of the Air

Recently I booked flights with Jetstar and asked whether they offered the opportunity to purchase carbon offsets. The answer was, “Yes – sort of. Only if you fly between Sydney and Melbourne-Avalon, but not between Sydney and Melbourne-Tullamarine.” So, disappointingly (and curiously), I couldn’t purchase any carbon offsets.

The price, however, had I been able to buy them, was ridiculously low: AU$0.70 per flight. Seventy cents! You couldn’t buy a pack of gum for 70c, but you can offset flying 700km for that amount? That doesn’t seem right.

Now, Carbon Planet estimate the emissions from a flight of this distance at 0.3 tonnes of carbon dioxide equivalent gasses (0.3 tCO2e), and Climate Spectator has today’s spot price of 1 tCO2e at >AU$20 on the European market and >AU$15 tCO2e on the New Zealand⁽¹⁾ market. So, realistically, offsetting my 0.3 tonnes of CO2e emissions should cost at least AU$5 – indeed, Carbon Planet offers me the opportunity to purchase the offsets for AU$7.50 (each way).

That means that Jetstar either has a carbon offset scheme 10 times more cost-effective than Carbon Planet (and most of Europe), or they’re engaging in a bit of greenwashing. Alternatively, Carbon Planet’s figures are wrong: QANTAS’ carbon calculator puts the emissions for a SYD/MEL flight at 0.108 tCO2e – fully 2/3rd lower. If that were realistic, it would put the market abatement cost at ~AU$1.50 (buying the offset from New Zealand.) QANTAS, who own Jetstar, offer the 0.108 tCO2e offset for AU$1.025. That’s comparable with Virgin Blue, who offer an offset for the same route for AU$1.09.

So what does that tell us? Since QANTAS owns Jetstar, we can virtually discount them having carbon offset schemes that cost different amounts – but Jetstar offers offsets for the same route for less than its parent company, which implies that it’s emitting less CO2e. If Jetstar’s fleet of smaller aircraft is more efficient that QANTAS’, that might be possible. However, Virgin Blue operates aircraft of a similar class to Jetstar, and its carbon offset is fully 55% more expensive. And all the airlines offer offsets (and presumably abatement) at less than the market value under international carbon trading schemes, and have stated emissions less than Carbon Planet. 

As so often, that probably comes down to the methodology used to measure emissions: Carbon Planet calculates 0.3 tCO2e for 700 km of air travel, while the ABC’s “Carbon Cops” estimates 0.127 tCO2e, and Carbon Neutral tells you it’s 0.24 tCO2e. 

What makes the difference? Future Climate has the answer: if you calculating just the impact from burning fuel, you get emissions of 0.13 tCO2e; take all the impacts associated with flight travel into account, however, and you get emissions of 0.26 tCO2e.

Now, without knowing how “All impacts associated with flight travel” are calculated I don’t want to give that method my seal of approval – but I can confidently say that just measuring running costs isn’t the best way of accounting for the actual environmental impacts of an action. Taken in combination with the vast difference between the apparent abatement costs for our airlines and the cost of carbon internationally (and this is with an Australian dollar at record highs; 12 months ago the gulf would have been even wider!), I am very, very sceptical of the efficacy of these carbon offsets.

On the other hand, if airlines really can undertake carbon abatement at nothing to fear from an emissions trading scheme in Australia ;-)

⁽¹⁾ As an aside: my spellchecker doesn’t recognise “New Zealand” – ouch.