If "AL Gore is a kind of nerdy superman"

... then let's see him take a leap!!

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.
Increased confidence in improved climate models projects sea-level increases of 14cm to 43cm by 2100, with further increases of up to 80cm in the following century, projected increased storm intensity, but not frequency, and sustained reductions in rainfall in Australia of about 0.1mm a day.
It has been well publicised that such changes could inundate some island nations and low-lying stretches of mainland countries, notably Bangladesh. CSIRO research predicts the biggest local effect would be to increase the impact of storm surges, particularly on Australia's tropical northern coastline.
These new findings are unlikely to silence the critics of the IPCC who describe them as alarmists: a tight-knit self-serving peloton earnestly riding at increasing speed in the wrong direction. In reply, the climate-change mainstream portray their critics as a handful of cranky, anorak-clad sociopaths and contrarians operating mostly outside the accepted scientific processes who, given the chance, would argue about what time it was.
The sceptics continue to argue that the development and evolution of these climate models is self-serving and predictive: in other words, that they assume a causal link between anthropogenic emissions of carbon dioxide and climate change and then retrofit their models to fit the theory. They claim that man-made increases in carbon dioxide levels are tiny compared with the Earth's natural exchanges: about 5.5 gigatonnes of carbon a year from human activity compared with about 750 gigatonnes in the atmosphere, another 1000 gigatonnes in the surface oceans and 2000 gigatonnes in vegetation and soils. The deep oceans, they say, contain 38,000 gigatonnes.
To them, increased confidence in such modelling is inevitable but reveals nothing except the ability to refine and adapt new data to reinforce a predetermined, but flawed, thesis. The sceptics argue that such modelling, even at its most advanced stage, is trying to reconcile natural systems that contain too many unknowns or unknowables to be meaningful.
These include the complex interaction between the surface ocean and deep oceans, the role of currents in shifting energy around the planet and the complex interplay between the surface and layers of the atmosphere that includes myriad feedback effects.
They claim these gaps inevitably have to be filled by assumptions, sometimes little more than educated guesses, which allow scope to manipulate outcomes and undermine the integrity of the findings. Such disagreement is absolutely normal in the history of scientific argument and debate. What makes climate change so different is the stakes. The economic, social and environmental effects of a significant change in the Earth's temperature are potentially so severe that the issue has lured the interest of the broader community and business, and right on their tails are the politicians.
Beyond doubt? British philosopher Karl Popper observed that there was no such thing as an inalienable truth in science. Science, he said, was never right, it was always just increasingly less wrong. The contestability of any scientific theory is fundamental to the robust and progressive development of science. Only by continually challenging scientific theories do we make progress.
While individuals in the political spin surrounding the climate-change debate repeatedly talk of the science being beyond doubt, the scientists are generally more circumspect.
The IPCC talks of increased confidence in its models rather than in absolutes, and acknowledges some, albeit fewer, uncertainties remain about aspects of their modelling. Their critics are more certain of the uncertainty.
US paleoclimatologist Tim Patterson told a congressional committee last year that there was no meaningful correlation between carbon dioxide levels and Earth's temperature during this geologic time frame.
"In fact, when carbon dioxide levels were over 10 times higher than they are now, about 450 million years ago, the planet was in the depths of the absolute coldest period in the last half-billion years," Patterson said.
The hockey stick debate: This refers to the shape of one of the high-profile diagrams used by the IPCC to demonstrate the relative severity of recent climate change. US climatologist Michael Mann has used tree rings, ice cores and other proxies of past climates to reconstruct northern hemisphere temperatures during the past 1000 years.
The modelling shows relatively stable temperatures for most of the millennium, then a sharp spike towards the end of the 20th century, producing a hockey stick appearance that gave a powerful visual cue to the scale of recent climate change and that figured prominently in public debate when the IPCC released its third assessment report in 2001. Mann's research said the 1990s were likely to be the warmest decade in the millennium.
In 2003, Canadian economist Ross McKitrick and engineer Stephen McIntyre tried to replicate the research and couldn't, claiming it was based on insufficient data and that it was the design of Mann's model that produced the hockey stick. What ensued was two years of claims and counter-claims on internet blogs and in the media between the scientists, and a growing band of supporters on both sides.
Eventually the US Congress bought into the dispute and commissioned an independent review, which found that Mann's statistical work was flawed and unable to support the claims of the hottest century, decade and year of the past millennium. Yet further modelling by other climate scientists has since supported Mann's original conclusions.
What is a credible authority? Mainstream climate scientists repeatedly make the point that while they stick to the accepted regime of advancing their theories and models through the discipline of publication and peer review in important scientific journals, most of their critics do not.
They also claim that many of their critics are industry-funded and not independent.
Their critics counter that the IPCC process has been dominated by government-funded scientists with an interest in promoting a climate problem that would justify further research and therefore funding.
Policy response: The new IPCC report will further fuel demand for immediate and drastic action to reduce greenhouse gas emissions to contain the effects of increasing climate change. Given the most recent projections, it is likely that the suite of policy responses may need to consider processes to help adapt to climate changes that appear increasingly likely to occur.