The essence of this article is that the issue is too important to be locked into an ideological stance and that is correct.
The very same holds true for our local flood protection discussion which is much too important to be held by ideological constraints.
An excerpt.
Too vital for guesses
Growing belief in global warming is pressuring governments and scientists to get their projections right. Environment writer Matthew Warren reports
September 02, 2006
AL Gore is a kind of nerdy superman. He pushed the development of the internet, won the popular vote in the 2000 US presidential election without being elected and has made a movie about himself giving a slide show about saving the planet from climate change.
His film An Inconvenient Truth, unsurprisingly, has polarised believers in severe climate change and their critics with its dire predictions of "a planetary emergency", including melting ice sheets, rises in sea levels, more frequent and severe cyclones and spreading tropical diseases.
Due to open in Australia on September 14, the film catalogues mainstream science on climatic change as the basis for a swift and decisive shift to lower greenhouse gas-emitting energy systems across the developed world.
Prominent Australian climate-change sceptic Bob Carter, a geologist at James Cook University in north Queensland, provided this blunt review: "Gore's circumstantial arguments are so weak that they are pathetic. It is simply incredible that they, and his film, are commanding public attention."
Cinema launches of the film across the world inevitably leave a trail of scientists praising or condemning the former US vice-president's claims. Despite nearly two decades of consolidated research on the subject, there is still limited agreement about climate-change science.
It is accepted that in the past 4.6 billion years the Earth's surface temperature has had a series of significant warm and cool periods, much hotter and cooler than now. Natural global warming 20,000 years ago removed giant sheets of ice that would have buried much of the northern hemisphere. The Earth is in a relatively cold period, not a warm one. Within these significant periods are much shorter and sharper natural fluctuations in temperature.
In the past millennium, temperature changes have manifest into smaller warming and cooling cycles; a noticeably warm spell from 1000 to 1400 called the Medieval Optimum, during which came the Viking colonisation of Greenland, followed by a Little Ice Age that lasted until the mid-19th century.
The Earth has been warming for about the past 200 years, a split-second in geological time. Since the start of the 20th century, global average surface temperatures have risen between 0.6C and 0.7C. Last year was the warmest year of the instrumental record, which dates back, coincidentally, only to the mid-19th century, when the present warming cycle kicked in. It is also agreed that the level of greenhouse gases have increased directly or indirectly because of human activities.
Concentrations of carbon dioxide are about 375 parts per million in the atmosphere, up from pre-industrial concentrations of about 280 parts per million. Other greenhouse gases such as methane and nitrous oxide are also higher. As Will Steffen, the director of resource and environmental studies at the Australian National University in Canberra, points out in a recent report to the federal Government, "the evidence for a warming Earth is stronger and the impacts of climate change are becoming observable".
Alarmists v sceptics: As the planet heats, so does the debate. The fundamental divide is between a growing majority of scientists who say there is increasingly certain evidence linking higher than predicted temperate changes with these known anthropogenic (man-made) increases in greenhouse gases, and a vocal minority who say such a claim is unsupportable.
The Intergovernmental Panel on Climate Change was established in 1988 and provides the collective opinion of government climate scientists from more than 120 member countries. It is considered the eminent body in the world on the science of climate change.
Since its first report in 1990, the IPCC has been evolving its modelling of the complex climate systems and has become more confident and certain of its modelled climate projections. In the 2001 third assessment report, it projected a temperature rise of between 1.4C and 5.8C by the end of the 21st century. Its draft fourth report, due for release next April, has narrowed the projected temperature range considerably to about 3C at the present rate of greenhouse gas emissions. Stabilising greenhouse gas emissions at present levels would reduce this increase by about 1C by 2100.
