THE ENVIROTRUTH: The modern global warming debate was ignited in 1989 when NASA climatologist Dr. James Hansen testified before a joint U.S. House and Senate committee that there was "a strong cause and effect relationship between the current climate" - then a blistering drought - "and human alteration of the atmosphere." His computer models predicted an average global temperature rise of 0.45°C between 1988 and 1997 and 8°C by 2050 due to greenhouse gas build-up. Despite enormous uncertainties in his simulations, it wasn't long before the politically correct view of the future included a global warming catastrophe.
Yet today, Hansen admits that his computer simulations were wrong and that current climate change models are unreliable (see related article by climatologist Dr. Patrick Michaels of the University of Virginia). After the U.S. spent $10 billion on this issue, Hansen wrote in the Proceedings of the National Academy of Sciences, "The forces that drive long-term climate changes are not known with an accuracy sufficient to define future climate changes." As more and more variables have been incorporated into the models, the amount of predicted change has decreased. Renowned Columbia University oceanographer/climatologist Dr. Wallace Broecker believes that more than one million variables influence climate change. Although not all are required to reasonably model climate, this fact underlines why contemporary computer simulations are not very accurate.
The problem is also due to the fact that, even though water vapor is the major greenhouse gas, it is essentially ignored by climate models. These simulations are so primitive that they are even unable to determine today's climate when starting with known past temperatures and rates of CO2 level rise.
Dr. Tim Patterson, professor of earth sciences (Paleoclimatology) at Carleton University, explains that, despite these obvious flaws, much of the current debate on global warming has been hijacked by theorists, relying primarily on these inaccurate models but working with little actual data. With the support of biologists, who generally lack a proper understanding of long-term climate dynamics, mass media and government have treated the more extreme of these theoretical scenarios as credible indicators of future environmental change, which they clearly are not.
Dr. Michaels puts the controversy into perspective: “Temperatures measured by surface thermometers have risen about 0.7°C in the last 100 years, but about half of that warming occurred before most changes in atmospheric carbon dioxide. The other half, which has occurred in the last three decades, is often attributed to human causation."
“If this is true, then we have a very good idea of future warming,” says Dr. Michaels. “While global climate models are incapable of predicting the distribution of regional and vertical climate change, they generally agree that once human-induced warming begins, it takes place at a constant (not increasing) rate. This is because the response of temperature to carbon dioxide becomes damped at higher concentrations, while it is generally assumed that the carbon dioxide increase itself is exponential, along with population. The mathematical combination of the two is a straight line.”
Dr. Michaels concludes that the resultant warming predicted by these computer models works out to approximately 1.6°C in the next 100 years. "Half of this amount, in the last 100 years, saw a doubling of life span and a quintupling of crop yields where economic freedom reigned," he says. "There is no reason to expect a sudden turnaround; rather, continued adaptation and prosperity are much more likely."
Dr. Roger Pocklington of the Bedford Institute of Oceanography says, "Professional doomsayers always pick the least likely, upper extremity, of the temperature range for their polemics, never the average." They also never explain that most of the computer models forecast much lower temperatures and that the average of these models is more in the range cited by Dr. Michaels.
Dr. Michaels concludes, "Changes in atmospheric carbon dioxide [the primary driver of temperature change in the computer models] have been much slower than anticipated by virtually all scientists 25 years ago. The increases are so small that they may not even be exponential. This predicts a damping of the already-small warming rate in coming decades."
A good illustration of how poorly today's Global Climate Models (GCMs) perform is obtained by comparing the rise in global average temperatures actually measured over the past two decades with how the GCMs used by the IPCC 'predict' they should have increased. As evident in the following graph (where measured temperature rise is indicated as an averaged trend) even the most conservative of the models used by the IPCC 'predict' significantly greater temperature rises than what actually occurred. How can we put any faith in the IPCC's predictions for the future when their forecasts are based solely on such inaccurate GCMs?
