Heavy subject

2 September 2022

There’s a greater focus than ever around environmental issues these days and, with the transport sector contributing around 18 per cent to our carbon (CO2) emissions, I’m glad about that.

Now, with the federal Climate Change Bill recently passed in parliament, we’ll be talking a lot more about CO2 emissions.

That’s fine, too, but there’s something about CO2 emissions that confuses people and, until recently, this included me.

I have been in the automotive industry for a long time, and most things I see appear to make sense. Except this… 

The average car emits around 140 grams of CO2 per kilometre travelled (g/km). Now, 140g is approaching the weight of a cricket ball and, if you’ve ever thrown one – or been hit by one! – you’ll appreciate that’s a fair weight.

When I think about this, it just seems too heavy, heavier in fact than the actual fuel I use to propel my vehicle.  

That’s because it is. And here’s why.  

Vehicle CO2 emissions include the weight of the burnt fuel (mostly carbon) and the weight of the oxygen that sticks itself to the carbon inside the vehicle combustion chamber. This mixture expels out the exhaust pipe as one molecule of carbon and two molecules of oxygen, CO2. And – wait for it – the oxygen in CO2 is three times the weight of the carbon.

So, that’s why categories of CO2 emissions from vehicles seem incredibly heavy.    

Pretty straightforward, huh?

Now, if only reaching net zero by 2050 was that simple…  

Words: VACC CEO Geoff Gwilym. As featured in the Herald Sun 2 September 2022.