Illusions of climate science.(Environment)

HOW HAVE WE COME to a situation where, as some polls suggest, most Australians are so concerned about dangerous climate change that they will put aside the very tools and technologies that have sustained clean air, clean water, nutritious food and long life? More importantly, is the perceived danger real and will the reduction of carbon dioxide emissions avert the perceived danger? Although there are many uncertainties to be resolved, it is clear that the community has been the subject of more than two decades of heavily biased propaganda.

In spite of claims to the contrary, there is no consensus of scientists supporting the findings and recommendations of the Intergovernmental Panel on Climate Change. There exists a large and vocal group of highly qualified dissenters (often denigrated as sceptics, deniers or worse). Published letters and opinions in the press suggest the scientific community is still divided and the community has not succumbed to the propaganda of human-caused global warming. Many in the community, with every justification, are awaiting more information about the costs and the economic and social impacts before lining up to march behind the government's carbon dioxide reduction banner.

A widely accepted conviction that dangerous climate change is actually pending will be required before the community will support the government's strategy to shut down fossil-fuel-dependent industries and willingly abandon the energy-dependent and satisfying lifestyle activities they enjoy. After all, in the cause of saving the planet we will all be required to give up a wide range of personal freedoms that we currently take for granted. We will want to be in full agreement that the alleged dangers are real and present, and that the course of government-imposed actions really will avert them.

ARE THE DANGERS OF HUMAN-CAUSED CLIMATE CHANGE REAL AND PRESENT?

HE NOTION of human-caused global warming has its origins in late-nineteenth-century speculation about the causes of past climate shifts, especially the ice ages when large parts of North America and Europe were under kilometres of ice. Svante Arrhenius of Sweden argued that intermit tent volcanic activity, and the injection of huge amounts of carbon dioxide into the atmosphere, had regulated retreats and advances of glaciations, but this theory has ,now been discarded. The Serbian Milutin Malenkovich's early-twentieth-century calculations linking the glaciations to changing characteristics of the earth's orbit around the sun is now in favour. Nevertheless, speculation linking potential global warming to the burning of fossil fuels, based on Arrhenius' theory, continued through the middle twentieth century.

During the 1960s and 1970s computer modelling was being developed to advance weather prediction. As they advanced, weather prediction models were adapted to crudely simulate climate, and a number of simple "what if?." experiments were carried out. For example, what would happen to Earth's temperature if the concentration of carbon dioxide in the atmosphere was doubled, or trebled? Some of these crude experiments suggested that increased carbon dioxide might significantly raise the temperature of the earth.

As a consequence of the early modelling experiments, the issue of dangerous human-caused global warming was a consistent underlying theme of a series of international and intergovernmental environmental conferences that preceded the formation of the United Nations Environment Program (UNEP) in the early 1970s.