The Cause Of Global Warming

Commentary, Environment, Frontier Centre, Global

It’s official: December 2000 was the third coldest since 1879. The folks at Environment Canada’s Winnipeg office say last month’s average temperature was minus 22°C, eight degrees below the seasonal normal. We already know that 1999 turned out a lot cooler than 1998. Shall we now conclude that a new Ice Age is imminent?

Not likely. A nation’s climate is the long-term aggregate of its daily weather events, including temperature extremes. Yet, based on a short-term warming trend in the 1990s, Environment Canada continues to issue what one might politely consider tendentious information on the topic of global warming and to recommend major changes to public policies that will affect everybody. The Province of Manitoba has embraced the theory, with Environment Minister Oscar Lathlin pledging significant financial support at a recent conference on the subject.

The idea of man-made global warming achieved respectability late in the 1970s. Its champion was NASA’s James Hansen, the “father of climate change theory”. His thesis, known as the greenhouse gas theory, postulated that the earth was in the midst of a warming trend caused by vast increases in the amount of carbon dioxide spewed into the atmosphere by the industrialized countries. This change, he believed, would prevent the planet from releasing as much heat as has been the norm into space, trapping us in a hothouse where accelerated warming would destroy our climatic equilibrium.

Before Hansen, scientific speculation had concluded that increased pollution led to global cooling because heat from the sun could not reach the earth’s surface as abundantly as before. Hansen’s new theory fit neatly with the warm temperatures we enjoyed in the 1990s, and it appealed to the apocalyptic mind just as much as the old one. Today, along with their ABC’s, our children are being taught the theory of man-made global warming in elementary school.

Inconvenient facts have intruded. Having intensively studied the role of CO² in the atmosphere, Hansen last August admitted he had been wrong. Carbon dioxide, he said, had nothing to do with global warming. He still believes it’s real and man-made but now thinks the culprits are methane, particulates and tropospheric ozone.

Other explanations, however, make more sense. Fossil records have informed us that the earth is in a long-term warming trend, but not because of human activity. The planet is still recovering from the mini-Ice Age of 1,000 AD, and tracking temperatures over thousands of years indicates we are still below the earth’s average during its recent history. The cycles behind the current warming are the consequence of solar change and the sun’s interaction with natural events on earth like volcanic eruptions.

Moreover, a new analysis seems to cast serious doubt on the methods used to gather data over the last decade. Scepticism about global warming had previously centred on the discrepancy between atmospheric and surface temperatures. Even while the latter seemed to be rising sharply, NASA’s satellite records indicated a slight cooling in the atmosphere. A New Zealand scientist, Vincent Gray, now observes that the anomaly arose from errors in the collection of ground temperatures.

In a study presented recently to the Wellington Branch of the Royal Society of New Zealand, Dr. Gray attributes the mistake to the location of weather stations. Between 1940 and 1975, much of the equipment used to measure temperatures was relocated from cities to airports, and data seemed to indicate cooling. Since 1975, two things have happened to reverse the findings: many rural stations were closed and urban expansion brought airports into, or closer to, the hubs of human activity. That proximity skewed the measures.

Fact is, we seemed to be getting warmer much faster than we actually were. Dr. Gray doesn’t think there has been any warming over the last century, man-made or natural: “The conclusion that global warming is an artefact of closeness to humans is proved by the fact that all measurements of global temperature that are made far from human habitation show no sign of any warming.” A link to his paper, The Cause of Global Warming, is provided at the bottom.

Dr. Gray examines four data sources — physical proof like tree rings and sediment over the last 1,000 years, readings from weather balloons over the last 44 years and satellites over the last 21 years, and surface temperatures at weather stations. Only the last source shows any warming, “an averaged mean global rise of a mere 0.6°C over 140 years, but [it] is intermittent and irregular. Individual records are highly variable, regional, and sometimes, particularly in remote areas, show no change, or even a fall in temperature.” He attributes this small, irregular rise to “changes in their thermal environment over long periods of time, such as better heating, larger buildings, darkening of surfaces, sealing of roads, increases in vehicles and aircraft, increased shielding from the atmosphere and deterioration of painted surfaces.”

This explanation casts a pall over recommendations that we adopt new “green” taxes on carbon sources to stop the planet’s alleged deterioration. If the problem were illusory, why would we want to comply with the Kyoto Accords, lower our living standards and increase poverty by imposing questionable constraints on economic growth? According to Wilf Falk, Manitoba’s chief statistician and a member of the federal-provincial modelling group looking at climate change, compliance will cost each Canadian $1,100 a year by 2010.

The CBC recently broadcast a documentary on the effects of global warming on Sachs Harbour, a small Inuit community on Banks Island on the Arctic Ocean. The feature reported that climatic change was causing the permafrost underneath the harbour to melt, along with the reactions of a populace frightened by the prospect.

It might be helpful to have our public channel pay a return visit to Sachs Harbour next summer when, no doubt, the icebergs will make their traditional return.