There are many who argue that the most pressing problem facing mankind is global warming. Former American vice president Al Gore was just here in Australia, arguing that very thing. He has produced a film to show the dangers of global warming. He and many others are convinced that this is our most pressing crisis, and must be addressed instantly and radically.
However not everyone is convinced. There are a number of scientists who do not buy the global warming doomsday scenarios. Indeed, there is a fair amount of debate about whether in fact global warming is taking place, and if it is, just how serious it might be. Unanimity on this matter is far from certain.
One scientist who remains sceptical is William Kininmonth, a former head of the National Climate Centre and a consultant to the World Meteorological Organisation. Writing in today’s Australian (September 12, 2006) he expresses doubt about the common wisdom on global warming.
In an article entitled “Don’t be Gored into going along ,” he states, “Climate change attracts attention because weather and climate extremes account for 70 per cent of natural disasters. Also, the historical evidence is that climate goes through gyrations that are beneficial or destructive for civilisations.”
Changing weather patterns seem to be the norm: “The periods of the Roman Empire, medieval Europe and the past 200 years were all of remarkable warmth. The Dark Ages of the first millennium and the Little Ice Age of the second were characterised by cold, by advanced mountain glaciers and by social turmoil.”
He continues, “For the past 10,000 years, the Earth has been near peak warmth in the climatic roller-coaster that has characterised the past million years. Yet only 20,000 years ago, great ice sheets covered much of North America and Europe; permanent glaciers were also present over southeastern Australia and Tasmania. The sea level was 130m lower than today and land bridges connected New Guinea and Tasmania with the Australian mainland. The Great Barrier Reef was but limestone cliffs bordering the Coral Sea.”
He then offers somewhat technical information having to do with climate change. He then declares, “Increasing the CO2 concentration will have little additional effect.” He goes on to elaborate:
“Evaporation of water vapour will constrain the Earth’s temperature and prevent a runaway greenhouse effect. Back radiation from the atmosphere because of greenhouse gases (water vapour, CO2 and so on), clouds and aerosols raises surface temperatures. But surface temperatures are also constrained by evaporation of water from plants, moist soil and the oceans. The tropical oceans generally do not exceed 30C and it is only over the arid inland that daytime temperatures exceed 40C. Any increase in back radiation because of increased CO2 will largely be offset by additional evaporation that will constrain the rise of surface temperature.”
Thus, “Collapse of the polar ice sheets and a sea level rise of several metres is an unlikely scenario.”
“There are predictions, based on computer models, that Australia’s rainfall will decrease as CO2 concentrations rise. According to published Bureau of Meteorology data, Australia (except for the southwest corner) was wetter during the second half of the 20th century than during the first. Against the prediction, as CO2 concentrations increased, there was an increase in continent-wide rainfall. These trends are likely to be no more than coincidence in the cycles of climate variability.”
He concludes, “The Earth’s climate system is extremely complex and we have only limited knowledge of many of its aspects. International collaboration is slowly unravelling some of the secrets and providing the basis for preparation and adaptation to change. Scientists’ continuing inability to predict with confidence a season in advance should be cause for hesitation when projections of decades to centuries are made. Computer models are not reality and alarmist predictions have no sound basis.”
Where real problems exist, they must be faced and dealt with. But there is at least a healthy minority of climate experts and scientists who are concerned about exaggerated claims about global warming. Since many of us are not scientists ourselves, we must rely on other experts. Given the division of opinion on this issue, the debate must be allowed to continue.