Given some of our contemporary educational standards, our society does seem to produce an inordinate number of young people who have been taught that passion is a good substitute for reason; and consequently that their ‘feelings’ matter more than turning to some patriarchal logo-centric European- constructed abstraction as a method to puzzle things out. Baiting these kids is a cheap thrill, but is amusing only for a few minutes before one worries about the consequences of their exercise of the franchise or the potential of their sitting on juries.
Still, we all have our guilty little pleasures; and one could be to keep introducing woolen toque-wearing, Bush-hating, politically correct youngsters to the dangers of dihydrogen monoxide (DHMO) contamination. Many of them seem alarmed when told that there are high concentrations of DHMO in everything we eat and drink; or that Neo-Nazis and George Bush make frequent use of it; that over-exposure to it is often lethal, and almost all us die saturated with the stuff (of course, we die really quickly if not saturated with it too… but why give the game away). The looks of alarm and damning-of-evil-corporations and those filthy capitalist Americans for contaminating the world are a lot of fun until they suddenly realize that dihydrogen monoxide is also known as H2O.
The debate over the presence and cause of climate change is almost as much fun… especially now that proponents of the man-made global warming theory have decided that they are the new orthodoxy and that only so-far unburned heretics could dare dispute the new truth. Millennialist visions of dire consequence abound, and if you don’t believe that climate change is coming, just watch Al Gore’s ‘An Inconvenient Truth’ or if you want some entertainment with your disaster prognostications, watch ‘The Day After Tomorrow’.
These must be true warnings, because we are told that a ‘majority of scientists’ agree that disaster is looming. Hmmm. Centuries ago, a majority of scientists also thought that the sun orbited the Earth. Decades ago, a similar majority thought that continental drift was an absurd notion. In 1830, the theory that much of Europe and North America had been once covered with ice was treated with howls of derision. A lot of the ‘facts’ we take as proven are based on consensus; and proponents of climate change should at least note that Noam Chomsky himself argues that consensus can be manufactured and manipulated. The Kyoto Agreement ought to be proof enough of that. One could also remember Paul Erlich and the doom-saying of the 1960s and ‘70s (again, apparently accepted by a ‘majority of scientists’ at the time).
Is climate change occurring? It seems so, but then the climate is constantly changing – with which a majority of geologists, paleontologists, meteorologists and honest environmentalists would agree. The questions are: How much will our climate change, and what is the cause? Human pollution may not necessarily be the most significant cause – not when any ambitious volcano can pump more greenhouse gases and ozone destroying chemicals in an afternoon than human industry can in a decade. Lest one think that is an exaggeration, this is exactly what Krakatoa did in 1883, Mount Pinatubo in 1991, and have a number of other volcanoes. Still, it doesn’t make much sense to let human pollution go unchecked, global warming or no.
The Climate Change issue contains many matters for considerable debate, but the hysteria that has accompanied the debate so far is certainly not helpful. There are some things we should all remember without diving into discussions about sunspot cycles, Mander Minimums, the HALE Cycle, deep water currents, and the innumerable other aspects of the arcane minutia of historical meteorology.
Human beings are a result of climate change. 600,000 years ago, Homo Erectus (aka ‘Peking Man’, ‘Java Man’, etc) was very much a going concern and had been so for over 1,200,000 years with little change. Spread widely through Europe, Africa and Asia, this remote cousin of ours was a highly successful species. But then so were a variety of earlier hominids — themselves also products of climate change after the world cooled and dried, forcing some apes to come out of Africa’s retreating jungles. Some of these earlier hominids had also managed to perpetuate themselves for hundreds of thousands of years. The world’s ecosystems didn’t seem to be demanding a self-cognitive aggressive and highly opportunistic tool user just yet. Then, as it so often does, the world changed again. 
For the last 30 million years, Earth has had permanent ice at its polar regions. The last time this happened was back in the great dying of the Permian Era (around 250 million years ago) when rapidly fluctuating ice-ages helped kill off some 90% of the species in existence at the time. One of the immensely successful subphyla that vanished were the trilobites, ending their 300 million years of life on the seabed. The Pleistocene Epoch itself (from 1,800,000 to 12,000 years ago) was also a time of a major ice age, but 600,000 years ago it got even worse with rapid shifts between severe glaciations – sometimes covering as much as 30% of Earth’s landmass – and sudden warmings.
Why does the earth’s temperature keep changing so? There are many causes: A minor wobble in the Earth’s axial tilt can influence the amount of sunlight received in the Polar Regions by as much as 20%, which happens quite often in geological time scales. Periodically, our sun burns a little more warmly, or a little cooler. Admittedly, it’s hard to think there could be much difference when the mean surface temperature of old Sol is around 5,000 degrees Celsius. But when one is basking in its glow some 150 million kilometers away, a degree or so of difference has a real effect on the energy we receive.
There are many other reasons why temperature has fluctuated so much in geological history – and there have been times when the Earth was much warmer than it is now. When Tyrannosaurus Rex was chasing Triceratops around in the Cretaceous, the mean global temperature appears to have been about 10 degrees Celsius higher than now. Over the past 10,000 years – as some ice core samples suggest — the mean average temperature on Earth has been wobbling up and down over a range of 8 degrees Celsius from century to century. During the Medieval Warming period, Vikings settled Greenland to farm and raise goats and sheep… then when the Mini-Ice Age of 1400-1850 began, they died off to the last man and farm animal.
So why bring up poor old Homo Erectus? Well, the long jump between us was a time of frequent environmental stress. Some 600,000 years ago, Erectus was doing just fine, while his remote cousin Homo Heidelbergensis was not nearly as widespread or numerous, being confined largely to Europe. At first glance, most of us would be hard put to place much difference between the two and the stone tools both used were much alike. Heidelberg man did have a larger brain case – sometimes rivaling our 1350 cubic centimeter (the human average) as theirs ranged between 1100 and 1400 CCs. Erectus came in with something between 950 and 1100 CCs.
It’s hard to deduce behavior from what little we know, but it also seems Heidelbergensis was a bit more partial than Erectus to big game hunting – which implies a brain with more capability for planning, decision making and teamwork. It also seems he buried his dead sometimes, which hints at the possibility of a bit of a spiritual dimension to their thinking, or at least a firm grasp of elementary hygiene.
Starting about 600,000 years ago until about 12,000 years before today, Europe (like Northern Asia and North America) turned into a bad place to be. The world alternated constantly between severe ice ages and then short intense warming periods which usually lasted for about 10,000 years. The wooded uplands Heidelberg man favored turned into tundra, and some of these distant ancestors turned back south. According to current Anthropological theory (which may be dead wrong of course), Heidelbergensis left two legacies – one was Homo Neanderthalensis, who didn’t seem to mind Ice Age Europe too much and stuck around until the descendents of the other legacy turned up. The other legacy appears to have been Homo Rhodesiensis, who looked pretty much like Heidelbergensis, but made his home in Southern Africa between 600,000 and 125,000 years ago.
Rhodesiensis gave rise to Homo Sapiens Idaltu – our last direct ancestor — remains of which were found in Ethiopia dating back some 160,000 years. Rhodesiensis and h.s. Idaltu were not yet finished with rapid climate change… Africa might not be nearly as cold as Europe, but the ice ages often led directly to severe desertification in Southern Africa. During a warming period, humanoids would venture out into the grasslands of the African interior, thrive and multiply, and then a few centuries later intense desertification would set in and the survivors had to move. Some paleontologists call this the ‘heat pump’ effect. Survival favored the adaptable and, eventually, some of Idaltu’s descendents seemed more adaptable than the others and Homo Sapiens Sapiens at last appeared on the scene sometime around 100,000 years ago.
Of course, life was still rough. Human genetic diversity is much less than that of most other animal species, and sometime before our kind began to radiate out of Africa (courtesy of the ‘heat pump’ effect outlined above), our ancestral population was reduced to something like 1,000 to 10,000 related individuals. The probable cause was the Toba volcanic eruption in Indonesia about 70,000 BC – which had catastrophic effects around much of the world; shortly afterwards Humanity started to spread across the planet.
Climate change was still not finished with us, and probably never will be. Lower sea levels around 13,000 BC let mankind cross over the Bering Straits into the Americas and had earlier let us radiate rapidly through Southeast Asia. The Neolithic agricultural revolution also owes much to rapid climate change. This is the thesis in Brian Fagan’s The Long Summer: How Climate Changed Civilization (Basic Books, New York, 2004). Fagan concludes his survey of the subject by reminding us that severe climate change could be a true challenge to our civilization.
However, while global warming seems to be happening – we surely do not yet have a consensus on the cause, nor are we really able to predict its effects. Several scientific disciplines being applied in concert can sometimes puzzle out what has happened in the past, but accurately predicting the future or understanding the present is always problematic. For all we know, we might even be staving off the appearance of mile-high glaciers bulldozing their way out of the north once again. After all, interglacial intervals in the late Pleistocene usually only lasted 10,000 years – which could mean our time will run out soon.
But we are the product of 600,000 years of rapid climate change. Actually, we are the descendents of 600,000 years worth of survivors; one would think something instinctual might have come out of this. For the toque-wearing youngster, however, scientific doubt doesn’t matter. All he knows is that Al Gore is right, a ‘majority of scientists’ are in agreement, and the only thing that can save humanity – or at least him and the bits he thinks deserve to be saved – is an immediate shutdown of industry and high technology civilization. Even the idea of an increase of a degree in the global temperature must surely be an unparalleled planetary disaster… but then someone who would be alarmed by the idea of dihydrogen monoxide contamination will buy almost anything.