Dennis Jensen (Tangney, Liberal Party) Share this | Hansard source

I support the motion put forward—in particular real assessment of the scientific data. The global water cycle atlas based on the IPCC fourth assessment report climate models by Lim and Roderick was published this year, using the same dataset for precipitation models as used by the fourth IPCC report. In the 39 models examined, the Australian average precipitation from 1970 to 1990 varied from—get this—190.6 millimetres to 1,059.1 millimetres per year. The observed annual precipitation for Australia over the 20th century falls in the range of 400 to 500 per year. Hence there were large differences between model simulated precipitation and observations.

Of the 39 model runs examined for the A1B scenario, 24 showed increases in Australian precipitation to the end of the 21st century while 15 showed decreases. The overall average across all model runs was for a small increase in Australian annual precipitation of eight millimetres per year by the end of the 21st century. Within that average, some models predict a drop in annual precipitation of as much as 100 millimetres per year—notably CSIRO—while others predict increases of the same order. Note that CSIRO is one of the most pessimistic models in terms of future rainfall predictions. Guess which model the Garnaut report relied on.

Much discussion of the Murray-Darling Basin relates to inflows. This is fair enough in terms of examining what is important, which is water in the system, but allows blame to be attributed to climate change. This is baloney, as can be seen by the Bureau of Meteorology rainfall charts, where it can clearly be seen that rainfall in the Murray-Darling Basin is normal. The reasons for reduced run-off are more plantations in the top of the catchments, catchment-wide drainage management plans put in place in the 1980s and 1990s to lower water tables and more efficient water use resulting in less leakage.

Dr Kevin Trenberth, IPCC coordinating lead author, stated in a Nature blog in June 2007:

I have often seen references to predictions of future climate by the Intergovernmental Panel on Climate Change (IPCC), presumably through the IPCC assessments …

Since the last report it is also often stated that the science is settled or done and now is the time for action. In fact there are no predictions by IPCC at all, and there never have been. There is no estimate, even probabilistically, as to the likelihood of any emissions scenario and no best guess. This is from an IPCC coordinating lead author, remember. Even if there were, the projections are based on model results that provide differences of the future climate relative to that today. None of the models used by IPCC are initialised to the observed state and none of the climate states in the models correspond even remotely to the current observed climate. In particular, the state of the oceans, sea ice and soil moisture has no relationship to the observed state at any recent time in any of the IPCC models.

There is neither an El Nino nor a Pacific decadal oscillation that replicates the recent past. Moreover, the starting climate in several of the models may depart significantly from the real climate, owing to errors. I postulate that regional climate change is impossible to deal with properly unless the models are initialised. The current projection method cannot work for many aspects of climate, especially those related to the water cycle. So much for the science being settled; we now have bad policy based on bad science. The solution to the Murray-Darling Basin problem will only result if the correct question is asked as to the causes of the problem. At present, green ideology is inhibiting the correct definition of the problem, and the Murray-Darling will continue to suffer as a result. Mr Deputy Speaker, I seek leave to table these documents.

Leave not granted.

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