Parliamentary record : Part I debates (27 February 1990)
Debates for 5th Assembly 1987 - 1990; ParliamentNT; Parliamentary Record; 5th Assembly 1987 - 1990
Made available by the Legislative Assembly of the Northern Territory
Northern Territory Legislative Assembly
Attribution International 4.0 (CC BY 4.0)
Legislative Assembly of the Northern Territory
DEBATES - Tuesday 27 February 1990 blanket in preventing heat loss. Principal greenhouse gases are water vapour, carbon dioxide, methane, nitrous oxide and chlorofluorocarbons. Their absorption of heat energy causes the temperature in the lower atmosphere to be some 300 higher than it would otherwise be. Strictly speaking, the Greenhouse Effect is a natural part of the earth ' s system and, without it, the earth would be too cold for life. What is new and what is widely referred to as the Greenhouse Effect is the significant increase within the last 200 years in the quantity of greenhouse gases. There is now irrefutable evidence that human activity since the industrial revolution has changed and will continue to change the composition of the atmosphere. Measurements of air trapped in glacial ice and in Antarctica show that, for 10 000 years prior to the industrial revolution, atmospheric carbon dioxide concentrations were stable at 280 parts per million. However, the concentrations began to increase during the 18th century and the average concentration is now 350 parts per mill ion and rising at about 0.4% per year. Similarly, over the same period, methane concentration in the atmosphere has more than doubled, from about 0.8 parts per million to 1.7 parts per million. Presently, methane is increasing at about 1% per year. Concentration of greenhouse gases' will continue to increase in the foreseeable future: Carbon dioxide is being added constantly to the atmosphere by industrial activities, particularly the burning of fossil fuels such as coal in power stations and petroleum in motor transport etc. Clearing of forests, and the decay or burning of the trees they once contained, also releases carbon dioxide into the atmosphere which was trapped .originallyduring the growth of the tree. Methane is released by fermentation processes in animals such as cattle and buffalo. It is also released during the mining and processing of coal and during the transport and distribution of natural gases. Mrs Padgham-Purich: All ruminants, not only cattle and buffalo. MrHATTON: I take the point made by the member for Koolpinyah. It comes from all ruminants. It is also released from organic matter decaying under certain conditions, such as in bogs, rice paddies and garbage dumps. While there is irrefutable evidence that the concentrations of greenhouse gases in the atmosphere are changing as a result of man1s activity, there are uncertainties about the climate changes which may occur a s a con sequence of thi s. Accordi ng to the CSI RO, however, the one certa in fact is that a warmer global atmosphere will result. Currently, the best estimates of the magnitude of global heating due to this predicted increase in carbon dioxide are temperature rises of an average of 1.50 to 4.50 by the year 2030. This may not seem very much, but its implications are enormous if we consider that, in Victoria last year, where temperatures were only 10 higher than average, the result was a reduction of up to 85% in some stone fruit crops. It is obvious that a small climatic shift may affect plant growth and reproduction. Further to this, climate change is likely to compound other environmental impacts that have already occurred as a result of human activity. Not only has human activity reduced the number of species of plants and animals, but it has already reduced the genetic diversity within species which enables them to survive adverse and changing conditions. It is possible that we could witness an increased tate of extinction in plants and animals that are unable to aqjust to the changes. Of immediate concern to us are indications from CSIRO that, as ~ consequence of a global 8760
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