Mr PETER FISHER(11.17) —I congratulate the honourable member for Dunkley (Mr Chynoweth) for bringing this important motion before the House. Human activity over the last century or more has brought about massive changes on a global scale. Natural systems, including the atmosphere, land and sea, and even life on earth, are clearly being changed. For some 100 years we have known that carbon dioxide and other gases in the atmosphere can cause a global warming. This greenhouse effect has become a matter for discussion and growing concern during the last two decades. Important questions include whether the predicted effects are occurring and, if so, whether they can be controlled or reversed.

As the effects on earth are potentially dramatic, research must be undertaken immediately to determine the extent and ramifications of any changes. We understand that some of the changes may result in massive rises in sea-levels, changes in the distribution and the intensity of storms, changes in rainfall patterns and growth rates and changes in the distribution of plants. Any understanding of the possible effects and problems will require considerable primary research into the earth's climate. We need a database and accurate models to be developed so that the magnitude of the changes we are observing can be determined.

We have to understand the vast differences between climates and the weather. There are many causes of climatic change other than the impact of the human on the environment. There is considerable evidence that solar output varies in a number of cyclical ways. Changes in the earth's orbit around the sun are able to affect the climate over time periods of 1,000 years or more. These effects, whilst generally local, may have up to a 10 per cent variation. Volcanic eruptions inject considerable amounts of aerosols such as dust and sulphur compounds into the atmosphere, which can affect global climate.

The composition of the atmosphere itself has a considerable effect on climate, and many gases are active and absorb and irradiate both short and long wave lengths. The most important gases we are discussing are ozone, carbon dioxide, nitrous oxide, methane and chlorofluorocarbons (CFCs), as well as water. Some are mainly internal to the natural system, as is water, while others, for example, CFCs, are man-made in origin and strictly external. The majority are naturally produced but have had their relative levels altered by man's activities-particularly ozone, carbon dioxide, nitrous oxide and methane. The changes produced by man are the ones causing this Parliament concern and resulting in the warming that is taking place.

The greenhouse effect, therefore, is a predicted global warming expected to result from an increase in the concentration of carbon dioxide and other gases in the atmosphere. This increased level of certain gases in the atmosphere allows sunlight to the earth's surface, but reduces the amount of radiation that escapes into space. The greenhouse effect becomes more serious with the dramatic increase in the use of fossil fuels as a source of heat and energy, and particularly this century, this is what has been happening. The level of carbon dioxide in the atmosphere has been increasing at a reasonably steady rate since reliable records began.

There is a wide range of chemicals with a number of important and widespread application for human activity such as propellants in aerosols, mentioned by the honourable member for Bass (Mr Smith), refrigerants, foam blowing agents and solvents. They are most dangerous due to their effect on the stratospheric ozone, but they also have a role as a greenhouse gas. CFCs, in particular, are extremely long-lived-up to 110 years-and therefore their build-up is a long term cause of concern. I have already referred to methane, which is a naturally occurring gas. Nitrous oxide is produced in considerable quantities by industrial processes. The two main sources of nitrous oxide are microbial breakdown of agricultural fertilisers and combustion processes. This gas is less well understood in the context of the greenhouse effect than other gases, but nitrous oxide clearly has the potential to be an important contributor to the problem.

What does all this mean and what effect would a greenhouse gas-induced temperature rise have on Australia, particularly on agricultural industries? The changes would vary very much between regions. Some areas may be advantaged. Generally, however, it is believed that agricultural regions would be more disadvantaged. Implications for rainfall in south-eastern Australia are not clear, but we could expect an increase in rainfall especially during the summer months. It is expected that the maximum level of daily rainfall would probably increase. This would increase the intensity and frequency of flooding and have important ramifications for the design of dams and flood drainage systems.

A particular problem could be that dams designed to cope with 100-year floods under previous climatic regions would no longer be safe at that level. Rainfall in south-western Australia would probably decrease, causing further increased problems with drought. We could expect an increase in tropical cyclone frequency and intensity. We could expect that higher temperatures would raise the equilibrium snowline by about 100 metres per degree. The predicted temperature rise would initially reduce the snow season in Australia and a relatively small rise could eliminate it completely. Any rise in sea levels would be a serious problem for Australia as so many Australians live in coastal regions. A rise could have a disproportionate effect on our nation.

There could well be a number of effects on the biosphere. Those likely include increased growth of various plant species, but not necessarily crop species or the edible portion of plants. Due to increased efficiency of water use by plants in a high carbon dioxide environment, some would probably extend their range into more arid areas, as shown by the pinus radiata display in the Commonwealth Scientific and Industrial Research Organisation (CSIRO) exhibition in Parliament House today.

If restrictions on the production of greenhouse gases are put in place, there will be a significant constraint on Australia's coal and chemical industries. As a change to nuclear power would be one of the ways to reduce the emission of carbon dioxide, the increased demand for uranium may well be to Australia's benefit. There are a number of other effects, including changes to the water table, possible increases in salinity and so forth. The result of the greenhouse effect on plants is difficult to predict. Problems arise because there are many factors involved and it is difficult to estimate the relative importance of each.

In conclusion, the Chairman of the CSIRO, Mr Neville Wran, said in a recent address to the Australian Conservation Foundation:

It could well be that if we go on burning fossil fuels in the absence of practical alternatives, the world will be forced to rely on nuclear energy . . . Many authorities have even been saying that 50 years out, we will be praying for nuclear energy.

Of course, Mr Wran did not say in his address to the Foundation that the massive cutback in funds for the CSIRO and for general research and development programs throughout Australia is a tragedy for which this Government should be condemned, and such condemnation should be part of this motion.