John Murphy (Lowe, Australian Labor Party) Share this | Link to this | Hansard source

Much has been made in recent times by climate change sceptics of supposed false or misleading claims made by scientists about the reality of global warming and the impact of human activities on the climate. A large part of the contrary evidence presented by the sceptics can be explained in terms of the subjective experiences of individuals. In the past, subjective impressions produced beliefs such as that the earth is flat and the sun goes around the earth. Obviously the preceding fables have been falsified by objective evidence. Unfortunately, despite ample objective evidence indicating that human activities are affecting the climate, climate change sceptics still offer up myth as fact.

Perhaps the most strident claim currently being articulated by the sceptics is that the world’s climate is actually cooling because the weather presently seems chillier. In fact, as explained by Dr Graeme Pearman, former Chief of the CSIRO Division of Marine and Atmospheric Research, the year-to-year variation in the mean planetary temperature is of the order of two- to three-tenths of a degree and the warming trend that we have seen over the last 100 years is only one-tenth of a degree per decade. According to Dr Pearman:

… if you only look at one ten-year period, you’re never going to be able to see the trend. You have to have a longer period of observations.

Senator Fielding has joined the debate by putting forward, amongst other misinformation, the unsubstantiated proposition that solar flares, which are large-scale explosive releases of energy from the surface of the sun, are causing the total output of heat from the sun to steadily increase and are responsible for the evident warming of the earth. And yet direct and highly accurate satellite and ground based measurements of the solar constant—that is, the radiant energy output of the sun—have been made since the 1970s and no such increase in the energy output from the sun has been detected, certainly none sufficient to account for the decades-long measured increase in average global temperatures.

There is a regular 11-year variation in solar activity, known as the solar cycle, that has been observed since the early 17th century. The incidence of solar flares has been found to be related to the solar cycle. They occur at a rate of several per day, when the sun is active, or less than once per week when the sun is quiet, as it is at present. If solar flares were responsible for increasing global temperatures then these temperature measurements should be synchronised with the solar cycle. No such correlation has been found and no significant flares have been recorded for the past two years by the three satellites whose primary mission is the observation of solar flares.

A survey of 3,000 scientists conducted by the University of Illinois in January this year found that 97 per cent of them think that humans play a role in climate change. This is a direct contradiction of the claim made by Professor Bob Carter of James Cook University in the Sydney Morning Herald of Wednesday, 19 August that it is untrue that ‘the vast majority of specialists in the field say that we have a major global warming problem, that it is caused by humans and it is probably getting worse’. Professor Carter has also claimed that ‘lower atmosphere satellite based measurements show little if any global warming since 1979’, and yet in July 2007 NASA published the results of a comprehensive review of surface and atmospheric temperature observations and trends conducted by the United States Climate Change Science Program, and that group identified and corrected errors in early versions of satellite and weather balloon data and concluded:

For recent decades, all current atmospheric data sets now show global-average warming that is similar to the surface warming.

Tonight I ask: how is it that Professor Carter can be apparently unaware of this information, two years old and now more than ever supporting the plethora of other evidence for global warming? The deliberate distortion of evidence has become a characteristic of the claims of climate change sceptics and is the sort of fallacious data that Senator Fielding has used to support his argument for opposing the government’s measures to reduce carbon dioxide emissions.

Australians gave the government a mandate to act on climate change at the last election. I implore the opposition to listen to the Australian people and to immediately support government action to mitigate the effects of climate change.