What is a tonne of carbon dioxide?
Dr Gelvin Stevenson of the Center for Economic and Environmental Partnership in the US worked out this example to help visualise the weight and volume of carbon dioxide emissions: Say you drive 13,000 kilometres in a large sports utility vehicles each year. The four tonnes of carbon emitted will weigh roughly the same as the car, and the pure gas would take up a volume equivalent to 140 small saloon cars. Put another way, each tonne of pure CO2 would take up roughly the space of a two storey house.
New Zealand’s contribution to worldwide carbon dioxide concentrations in 2010, taking into account the carbon dioxide removed from the atmosphere by activities like forestry, is 72 million tonnes.