A dash of cold water for global warming forecast

FOREST fires rage out of control despite water-bombing by helicopters. A sweltering heatwave grips the outback. Is this Australia? No, it’s Scotland enjoying its driest spring on record. The war might have come and gone, and we might be having an election next week, but all Scotland can talk about is the odd weather. Welcome to global warming.

Or is it? I remain doggedly unconvinced. Certainly, the past decade has seen shorter winters in Scotland. But that only proves the climate is highly variable. Certainly, we are seeing a global bounce in temperature since the mini cold spasm that gripped the northern hemisphere for 600 years ended in the mid-19th century. But before that it was even warmer than it is now. As for a runaway global warming caused by the side-effects of nasty Western industrialisation - there is no unambiguous proof. Indeed, the one bit of proof there supposedly was has just been revealed as bogus.

Suppose I told you that North Korea will soon have a higher standard of living than the United States. Doubtful, since its benighted population are starving. Or would you be willing to bet that Swaziland and Gabon in AIDS-plagued Africa will overtake Australia economically before long? Well, somebody is seriously predicting these fantasies will become reality: the scientific experts of the United Nations Intergovernmental Panel on Climate Change (IPCC) who preach the gospel of global warming.

These are the economic growth forecasts used by the IPCC to calculate the likely emissions of greenhouse gases from industry. Last year, the IPCC released, as the main result of its massive Third Assessment Review, a set of figures that have since become the most cited numbers in environmental politics. The panel reported that the Earth’s average "surface temperature is projected to increase by 1.4 to 5.8C over the period 1990 to 2100".

When the IPCC appeared with this forecast, there were widespread media stories referring to its dire claims. One Scottish newspaper likened the predictions to the world turning into the dark, wasted planet depicted in the science fiction movie Bladerunner. The IPCC report serves as the basis for all international climate negotiations, including the Kyoto Convention on reducing greenhouse gas emission.

But now evidence is emerging that the scientific foundations of the 2001 report are deeply flawed. If this analysis is correct, the central scientific tenets of global warming are grossly exaggerated. Two distinguished academics have examined the IPCC report in detail and declared it "technically unsound" - a euphemism for being so wrong as to be useless.

They are Dr Ian Castles, formerly the head of Australia’s national office of statistics, and David Henderson of the Westminster Business School in London and formerly the chief economist of the OECD, the major international development body. Their findings are published this month in the scientific journal Energy and Environment.

According to Castles and Henderson, the IPCC got it wrong for the simplest of reasons - the climate scientists were not versed in economics. So they made the most elementary mistakes in economic forecasting, as they tried to predict the growth of industry and the resulting demand for fossil fuels. The IPCC report vastly overstates the growth rates for developing countries and consequently greatly overestimates the magnitude of global warming over the next 100 years. The false methodology in the IPCC Third Assessment came to light only after it was published, when the data on which the projections were based was released on the IPCC website.

According to Castles and Henderson, the first mistake the IPCC has made is the central "scenario" which predicts how the world economy will evolve over the next century. The IPCC assumed that the US (and most of the developed world) would stop growing by 2030, while the rest of the developing world would catch up in terms of per capita income, then surge ahead. This absurd vision was adopted so as not to upset the Third World nations that form the bulk of UN membership.

In 1990, the combined national income (GDP) of the rich OECD nations, including Japan, North America and Europe, was $16.5 trillion, while the combined GDP of the major developing regions - Africa, Latin America and Asia - totalled only $3.5 trillion. But the IPCC projections propel the developing nations on to a growth trajectory that overtakes OECD nations in only 30 years, and then soars to three times the OECD levels by 2100.

Once these false economic predictions are fed into the climate change models, they vastly exaggerate the increase in greenhouse gas emissions. For example, the IPCC estimated that in this decade alone carbon emissions would increase by 800 million tonnes in the developing world. But that would be greater than the increase for the world as a whole between 1990 and 2000.

Castles and Henderson claim the IPCC has made an even more elementary error in its sums. This concerns how the size and growth of different economies are measured against each other. Different countries use different currencies. To compare them you have to convert one currency into another - but at what exchange rate? There are two choices: the current market rate or what is called purchasing power parity (PPP), which measures the true spending power of the local currency.

The market rate method used by the IPCC distorts reality. Based on market exchange rates, the current average per capita income in Asia is $500 compared to $20,000 in the rich OECD nations - that is a gap of 40 to one. Castles says that, properly measured on a PPP basis - which accounts for basic items being cheap in poorer nations - the real income gap between the two groups is actually ten to one. If the gap is only ten to one, then the amount of economic growth needed to catch up with the West would be far smaller than that projected by the IPCC. It follows that the rise in carbon emissions would also be far smaller.

But IPCC was not just involved in perpetrating bad science. There is evidence the IPCC team tried to persuade reputable scientists to deliberately distort their data to fit the climate outcomes they wanted to see. One person approached was the leading economic modeller John Reilly, of the Massachusetts Institute of Technology’s joint programme on the science and policy of global change. According to Reilly, the IPCC group attempted to find economists to "tweak" long-range models to get the desired emissions results. "They wanted our group [at MIT] to do this, but we just refused."

Where does all this get us? It is certainly not carte blanche to pollute the atmosphere. But it suggests we need to accept the weather has a will of its own - and we are lucky enough to be living in one of its more benign dispensations. Better then to put our cash into genuine economic growth in the Third World than investing in faddish "green" technologies in the West which add to costs unnecessarily. And we need more public discussion of the findings of Castles and Henderson. After all, only the future of the world is riding on the outcome of this academic dispute.