Christine Milne (Tasmania, Australian Greens) Share this | Link to this | Hansard source

My question is to the Minister for Climate Change and Water, Senator Wong. It relates to the climate model chosen for the Treasury modelling and notes further that the choice of climate model determines how much we will need to reduce greenhouse gases in order to meet the government’s specified targets of 450 and 550 parts per million of CO2e. Can the minister confirm that the government chose to use only the MAGICC climate model and did not use other models like the Hadley Centre or the University of Victoria, Canada, climate models? And can the minister explain the climate consequences of basing global and domestic action on the MAGICC model instead of the Hadley or the University of Victoria models?

Penny Wong (SA, Australian Labor Party, Minister for Climate Change and Water) Share this | Link to this | Hansard source

To assist the chamber and to ensure that I also understand the question: I understand that when the senator talks about ‘MAGICC’ she is talking about the model for the assessment of greenhouse gas induced climate change—is that correct?

Christine Milne (Tasmania, Australian Greens) Share this | Link to this | Hansard source

Yes.

Penny Wong (SA, Australian Labor Party, Minister for Climate Change and Water) Share this | Link to this | Hansard source

That is the model that Treasury chose to use for the modelling. It is a model that I am advised was also used by the Intergovernmental Panel on Climate Change, and it is highly regarded and well established for this type of analysis. The cumulative global emissions in the scenarios in the government’s report are consistent with estimates of global emissions projected for the relevant stabilisation levels also presented in the Stern review, and I know that the senator would be familiar with those.

In relation to the Hadley Centre and the University of Victoria, Canada, as I said, I am advised that it was the model for the assessment of greenhouse gas induced climate change that was utilised by Treasury. I am advised that it is a model that incorporates a suite of coupled-gas-cycle climate and ice-melt models integrated into a single software package. This software allows the user to determine changes in greenhouse gas concentrations, global mean surface air temperature and sea level resulting from anthropogenic emissions. The current version of MAGICC was developed primarily with funding from the United States Environmental Protection Agency.

Christine Milne (Tasmania, Australian Greens) Share this | Link to this | Hansard source

Mr President, I ask a supplementary question. I thank the minister for her answer but note that she failed to indicate to the Senate that by choosing only the MAGICC model the government chose a path that would allow Australia and the world to emit up to 30 per cent more greenhouse gases in order to meet the same climate outcome than would have been the case had other models been chosen. I ask the minister: if a more pessimistic model such as the Hadley model proves to be a more accurate reflection of reality, could the government’s choice of model contribute to tipping points in the climate being triggered and, if so, why did the government choose only one relatively optimistic model when it would have been more sensible and risk averse to base action on the more pessimistic models?

Penny Wong (SA, Australian Labor Party, Minister for Climate Change and Water) Share this | Link to this | Hansard source

First, in relation to the risk analysis, I would make the point that I have been very—

Honourable Senators:

Honourable senators interjecting—

John Hogg (President) Share this | Link to this | Hansard source

Order! It is disorderly for those on my right to be interfering while your minister wants to answer the question.

Penny Wong (SA, Australian Labor Party, Minister for Climate Change and Water) Share this | Link to this | Hansard source

As I was saying, I have made it clear that there are a range of matters that the government will draw on in making its decisions in relation to the Carbon Pollution Reduction Scheme. As the senator knows, there are four different models in the Treasury modelling—two Garnaut and two government models. There is also the range of discussions and consultations in relation to the green paper. So the modelling was never put forward as a blueprint because by definition it is modelling of a range of different scenarios and it is important information for the community and the government to consider. Of course we remind— (Time expired)

John Hogg (President) Share this | Link to this | Hansard source

I draw the attention of the chamber to the fact that when the clock was stopped for interjections during the minister’s previous answer the clock would not reset properly, which is why it advanced so quickly towards the end of her answer. I assure you, though, that the appropriate time was allocated for the answer.

Christine Milne (Tasmania, Australian Greens) Share this | Link to this | Hansard source

Mr President, I ask a further supplementary question. I did ask the minister why the government chose one relatively optimistic model when it would have been more sensible to look at the more pessimistic models. I ask: in view of the fact that other countries going to the global climate negotiations in Poznan will have conducted a more robust and risk averse analysis based on a range of models, will the government now rerun the Treasury modelling using a range of climate models so that Australia’s targets can be more rigorously assessed in the global context, and will the government now rerun the Treasury modelling to examine the 350 parts per million trajectory, and, if not, why not?

Penny Wong (SA, Australian Labor Party, Minister for Climate Change and Water) Share this | Link to this | Hansard source

The answer to the last one is no, and I think I have previously indicated that to you, Senator Milne. We have undertaken the modelling and we have put it out. I disagree, with respect, with the ‘relatively optimistic’ description. We used a model that, on my advice, was used by the IPCC. As in any area of science, there is ongoing research into the relationship between global emissions and greenhouse gas concentrations, which is the issue that underlies your question. The government will continue to support climate research and analysis, including economic and climate model development by CSIRO, ABARE and the Treasury. I would remind the Senate that the modelling undertaken by Treasury is the largest modelling exercise that has been done by government in Australia. It is rigorous and it has provided very useful information to us all. (Time expired)