Global warming raises political temperature

The National Party convention at Tweed Heads a few weeks ago made clear its opposition to Australia ratifying the 1997 Kyoto treaty's protocol on greenhouse gas emissions. This stand places it at odds with Environment Minister Senator Robert Hill. He plans to veto projects emitting more than 500,000 tons of carbon dioxide each year, as a step towards meeting the treaty's requirements. It therefore looks as though the global warming issue and Australia's position on the Kyoto treaty will be one of the critical political and economic issues for the coming year.

Australia's economic future would be dramatically affected for the worse if we were to undertake to reduce significantly our use of hydrocarbons for energy production, or methane emissions by grazing animals. However, if we do not reduce hydrocarbon use and emissions, the European Union may impose trade sanctions on us. So the international and domestic politics of global warming and greenhouse gas emissions are delicate. Moreover, current moves are taking place against a background of important scientific progress in knowledge of global warming. The emerging scientific facts may prove pivotal in determining the economic and political outcomes, both domestically and internationally.

Global warming is not new. The fossil records, evidence from tree rings, ice cores and ocean sediments, and other indirect measures of earth temperatures, reveal significant variations over tens of thousands of years. Temperature fluctuations quite independent of human activity are normal.

The immediate question for the world, however, is whether the recent record reveals significant temperature changes. It is within the last 50 years that we have experienced major increases in the release into the atmosphere of the so-called greenhouse gases - mainly carbon dioxide and methane - which some climatologists and environmentalists have argued are causing global warming and raising the possibility of catastrophic climatic changes. If it can be shown that there have been significant temperature changes associated with these emissions, as the Kyoto treaty has assumed, the case for emission controls is strengthened. Conversely, if no significant warming is demonstrated Kyoto becomes irrelevant.

The climatic models accepted as a basis for the Kyoto treaty predicted that measurements would show that atmospheric temperatures have risen over the past twenty years. This prediction allows a crucial test for the global warming hypothesis. If the prediction is not fulfilled the hypothesis must be discarded, and with it the case for emission controls under the Kyoto protocols collapses.

The measurement of the earth's surface temperature has been carried out for many years by thousands of thermometers placed in every country and housed in standard boxes called Stevenson Screens. Since they have to be read regularly, they are placed in post offices, farms, radio stations, lighthouses, airports, etc and mostly in towns and cities. Marine temperatures are gathered by ships.

As Australian scientist John Daly points out, the record of these surface temperatures from 1880 to 2000 shows a sustained warming of about 0.6 of a degree Celsius from 1890 to 1940, a cooling of 0.2 C from 1940 to 1975, followed by a warming of 0.4 C from 1975 to the present. It is the portion of this warming phase from 1979 to the present which is of particular interest, especially when compared with the measurements of atmospheric temperature over the same period.

These atmospheric measurements were made by satellites using highly sophisticated and accurate measuring devices. There is confirmation of the accuracy of the satellite records from quite independent recordings by a different method - helium balloons sent aloft and using radiosondes, as they are called, to measure exactly the same part of the atmosphere measured by satellites. These measures proved to be highly consistent with each other.

The results from both sets of atmospheric measurements showed a trend at odds with that shown by the surface measurements. Atmospheric temperatures showed a warming of less than 0.1 C, due to the El Nino of 1997-98. Prior to then the satellites were showing a slight global cooling, which persisted in the Southern Hemisphere, with the Northern Hemisphere showing only the slight warming over the 21 year period.

How, then, can we reconcile a surface warming of 0.4 C over the 21 years with this atmospheric record of virtually no change? To add to the puzzle, the surface records taken in North America, Australia, and Western Europe are in close agreement with the atmospheric recordings. The answer seems to be that in these countries the records have been better collected and maintained than elsewhere, especially in those countries racked by warfare and upheaval, where the records showed rising surface temperature. Further evidence has been adduced to throw doubt upon the reliability of the surface measures in various locations, especially the local distortions caused by heat-producing activities in urban and airport areas. A significant proportion of the surface measurements are therefore suspect, while the atmospheric measurements are above suspicion and reliable.

The upshot is that the climatic model predictions which formed the basis of the Kyoto recommendations have been invalidated. This is the conclusion reached in January this year by an expert panel of scientific specialists in temperature measurements commissioned by the United States Academy of Sciences. The best data and eminent scientific opinion find no real evidence of global warming caused by greenhouse gas emissions. With so much of economic and social importance at stake, it would be the height of scientific, economic and political irrationality for Australia to ratify the Kyoto treaty or to take any steps to reduce emissions. The United States has refused to ratify the Kyoto treaty. Australia should also heed a petition opposing the treaty signed by over 17,000 American scientists. It reads in part:

"We urge the United States government to reject the global warming agreement that was written in Kyoto, Japan in December, 1997 and any other similar proposals. ... There is no convincing scientific evidence that human release of carbon dioxide, methane or other greenhouse gases is causing, or will, in the foreseeable future, cause catastrophic heating of the Earth's atmosphere and disruption of the Earth's climate".