John Murphy (Reid, Australian Labor Party) Share this | Hansard source

Whilst the scientific scepticism and the hostility to scientists of the Leader of the Opposition and his followers has become a national embarrassment, readily comprehensible evidence that supports the government's actions to restrict carbon dioxide emissions continues to grow, as do atmospheric carbon dioxide levels. There is now so much unarguable evidence that carbon dioxide emitted from burning fossil fuels is driving global warming and climate change, as well as the acidification of sea water, that it is difficult to decide where to start.

Perhaps I could start tonight with an account of discoveries by geologists who have examined the fossil record of the temperatures and sea levels from the Eemian, the interglacial period that occurred 130,000 years ago that preceded the current Holocene interglacial in which we are now living.

Since 1837, when Karl Schimper and Louis Agassiz first presented evidence for extensive glaciations based on data collected in the Alps, it has been understood that the earth has undergone a succession of ice ages now known as the Pliocene-Quaternary glaciation, which started about 2.6 million years ago. There is compelling evidence that icesheets and sea levels have advanced and retreated on 40,000 and 100,000-year cycles during the Pliocene-Quaternary epoch, and that these glaciations and associated changes have been interspersed with much shorter and warmer interglacials, such as the preceding Eemian interglacial that I have just referred to.

Rather like today's climate change deniers who dispute the evidence for climate change, the 1830s audience for Schimper and Agassiz's theory of ice ages was very critical of, or even opposed to, the new idea because it contradicted the then established theories of climate history. Most scientists of that time thought that the earth had been gradually cooling down since its birth as a molten globe and that preceding ages were hotter rather than cooler as Schimper and Agassiz had proposed. Yet, as we know, Schimper and Agassiz were correct in their interpretation of the evidence and, despite the protests of the doubters and deniers of that time, the regular advance and retreat of the ice over hundreds of thousands of years is now accepted as an historical fact established beyond any dispute.

So it is for global warming driven by carbon dioxide emissions, although what is different about the present concocted argument is that the very great majority of scientists accept the evidence for human-induced global warming and climate change caused by carbon dioxide emissions whilst those denying the evidence are either scientific illiterates, amoral political opportunists or undeclared campaigners for vested interests.

What is most concerning about the geological evidence from the Eemian period is the fact that data from ice cores and ocean sediments show that average global temperatures were around two degrees warmer than today's temperatures, while other evidence shows clearly that the sea level was four to six metres higher than at present, with the water coming from melted icecaps in Greenland and the Antarctic.

Although the Eemian interglacial may have been warmer than the present interglacial due to natural variation, what is different about our time is that the initially lower temperatures and sea levels are being driven upwards by distinctly unnatural carbon dioxide emissions produced by human activity. Fossil reef terraces from the Eemian period are a common sight along tropical coasts, and examples sitting four to six metres higher than current sea levels can be seen throughout the Caribbean. Eemian reefs are also obvious along Australian coasts and, according to Dr Stirling of the Australian National University, in Western Australia fossil Eemian reefs occur between 2.5 and 3.4 metres above present mean low water spring at Mowbowra Creek, Vlaming Head, Southern Yardie Creek and Burney Point.

How would a sea level rise of this magnitude affect the many people, even in my own electorate, who live on the foreshores of Sydney Harbour and who would certainly be forced from their homes by these sorts of increases in sea level? If nothing is done to restrict emissions, an atmospheric carbon dioxide concentration of 450 parts per million will be reached within 20 years, up from the present level of over 380 parts per million, and that increase will, on the evidence, push up average global temperatures by around two degrees to a level not experienced since the Eemian period 130,000 years ago.

A sea level rise of four to six metres may therefore be in store for people living on Australia's coastline if the destructive policies of the opposition and climate change deniers continue to obstruct measures to reduce carbon dioxide emissions. (Time expired)

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