asked the Minister representing the Treasurer, upon notice, on 18 August 2011:

With reference to the Treasury Carbon Tax modelling, Strong growth, low pollution: Modelling a carbon price, under the medium global action scenario, what is the projected parts per million concentration of CO2-e in the atmosphere in 2050.

The Treasurer has provided the following answer to the honourable senator's question:

The atmospheric concentration of greenhouse gases is projected to be around 556 parts per million in 2050 in the medium global action scenario. The concentration level is projected to increase further before stabilising at 550 parts per million by around 2100.