Scientists have found other indications of global cooling. For one thing there has been a noticeable expansion of the great belt of dry, high-altitude polar winds —the so-called circumpolar vortex—that sweep from west to east around the top and bottom of the world.

Sunspot Cycle. The changing weather is apparently connected with differences in the amount of energy that the earth's surface receives from the sun. Changes in the earth's tilt and distance from the sun could, for instance, significantly increase or decrease the amount of solar radiation falling on either hemisphere—thereby altering the earth's climate. Some observers have tried to connect the eleven-year sunspot cycle with climate patterns, but have so far been unable to provide a satisfactory explanation of how the cycle might be involved.

Man, too, may be somewhat responsible for the cooling trend. The University of Wisconsin's Reid A. Bryson and other climatologists suggest that dust and other particles released into the atmosphere as a result of farming and fuel burning may be blocking more and more sunlight from reaching and heating the surface of the earth.

Whatever the cause of the cooling trend, its effects could be extremely serious, if not catastrophic. Scientists figure that only a 1% decrease in the amount of sunlight hitting the earth's surface could tip the climatic balance, and cool the planet enough to send it sliding down the road to another ice age within only a few hundred years.

There are ominous signs that the Earth’s weather patterns have begun to change dramatically and that these changes may portend a drastic decline in food production – with serious political implications for just about every nation on Earth. The drop in food output could begin quite soon, perhaps only 10 years from now. The regions destined to feel its impact are the great wheat-producing lands of Canada and the U.S.S.R. in the North, along with a number of marginally self-sufficient tropical areas – parts of India, Pakistan, Bangladesh, Indochina and Indonesia – where the growing season is dependent upon the rains brought by the monsoon.

In April, 1975, in an issue mostly taken up with stories about the collapse of the American-backed government of South Vietnam, NEWSWEEK published a small back-page article about a very different kind of disaster. Citing "ominous signs that the earth's weather patterns have begun to change dramatically," the magazine warned of an impending "drastic decline in food production." Political disruptions stemming from food shortages could affect "just about every nation on earth." Scientists urged governments to consider emergency action to head off the terrible threat of . . . well, if you had been following the climate-change debates at the time, you'd have known that the threat was: global cooling.

How did NEWSWEEK—or for that matter, Time magazine, which also ran a story on the subject in the mid-1970s—get things so wrong? In fact, the story wasn't "wrong" in the journalistic sense of "inaccurate." Some scientists indeed thought the Earth might be cooling in the 1970s, and some laymen—even one as sophisticated and well-educated as Isaac Asimov—saw potentially dire implications for climate and food production. After all, Ice Ages were common in Earth's history; if anything, the warm "interglacial" period in which human civilization evolved, and still exists, is the exception. The cause of these periodic climatic shifts is still being studied and debated, but many scientists believe they are influenced by small changes in the Earth's orbit around the Sun (including its "eccentricity," or the extent to which it deviates from a perfect circle) and the tilt of its rotation.

As late as 1992, in a story that for some reason has gotten far less attention, NEWSWEEK revisited the Ice Age threat, this time posing it as a perverse consequence of the greenhouse effect. Citing the theories of an "amateur scientist and professional prophet of doom named John Hamaker," the article raised the specter that a small increase in air temperature could cause more snow to fall in places like northern Greenland, where the ground is often bare. (Extremely cold air doesn't hold enough moisture for a good snowfall.) Increased snow cover, by reflecting more sunlight back into space, could trigger a return of the glaciers to North America. Although the intricate web of positive and negative feedbacks that control climate are still not fully understood, that particular scenario hasn't gotten much attention in the last decade.

Following the U.S. Senate's vote today on a global warming measure it is an opportune time to examine the recent and quite remarkable momentum shift taking place in climate science. Many former believers in catastrophic man-made global warming have recently reversed themselves and are now climate skeptics. The names included below are just a sampling of the prominent scientists who have spoken out recently to oppose former Vice President Al Gore, the United Nations, and the media driven "consensus" on man-made global warming.

Meteorologist Dr. Reid Bryson, the founding chairman of the Department of Meteorology at University of Wisconsin (now the Department of Oceanic and Atmospheric Sciences, was pivotal in promoting the coming ice age scare of the 1970’s has now converted into a leading global warming skeptic. In February 8, 2007 Bryson dismissed what he terms "sky is falling" man-made global warming fears. Bryson, was on the United Nations Global 500 Roll of Honor and was identified by the British Institute of Geographers as the most frequently cited climatologist in the world. "Before there were enough people to make any difference at all, two million years ago, nobody was changing the climate, yet the climate was changing, okay?" Bryson told the May 2007 issue of Energy Cooperative News. "All this argument is the temperature going up or not, it’s absurd. Of course it’s going up. It has gone up since the early 1800s, before the Industrial Revolution, because we’re coming out of the Little Ice Age, not because we’re putting more carbon dioxide into the air," Bryson said. "You can go outside and spit and have the same effect as doubling carbon dioxide," he added. "We cannot say what part of that warming was due to mankind's addition of ‘greenhouse gases’ until we consider the other possible factors, such as aerosols. The aerosol content of the atmosphere was measured during the past century, but to my knowledge this data was never used. We can say that the question of anthropogenic modification of the climate is an important question -- too important to ignore. However, it has now become a media free-for-all and a political issue more than a scientific problem," Bryson explained in 2005.

Climate change will be considered a joke in five years time, meteorologist Augie Auer told the annual meeting of Mid Canterbury Federated Farmers in Ashburton this week. Man's contribution to the greenhouse gases was so small we couldn't change the climate if we tried, he maintained. "We're all going to survive this. It's all going to be a joke in five years," he said.

A combination of misinterpreted and misguided science, media hype, and political spin had created the current hysteria and it was time to put a stop to it. "It is time to attack the myth of global warming," he said.

Water vapour was responsible for 95 per cent of the greenhouse effect, an effect which was vital to keep the world warm, he explained. "If we didn't have the greenhouse effect the planet would be at minus 18 deg C but because we do have the greenhouse effect it is plus 15 deg C, all the time."

The other greenhouse gases: carbon dioxide, methane, nitrogen dioxide, and various others including CFCs, contributed only five per cent of the effect, carbon dioxide being by far the greatest contributor at 3.6 per cent.

However, carbon dioxide as a result of man's activities was only 3.2 per cent of that, hence only 0.12 per cent of the greenhouse gases in total. Human-related methane, nitrogen dioxide and CFCs etc made similarly minuscule contributions to the effect: 0.066, 0.047 and 0.046 per cent respectively.

"That ought to be the end of the argument, there and then," he said. "We couldn't do it (change the climate) even if we wanted to because water vapour dominates."