February 16, 2007
Who's Afraid of Global Warming?By J.R. Dunn
Science works by means of prediction. Once data is collected and evaluated, and a hypothesis formed, scientific method requires that certain predictions be made to act as tests of the overall theory. If the predictions work out, we can regard the hypothesis as proven. If not, we vow to do better next time.
Take general relativity, for instance. (Full disclosure: this example is stolen in toto from Rush Limbaugh's program of February 2nd.) Einstein's theory was dismissed as lunatic by many classical physicists on its introduction in 1905. But he proposed a series of simple and straightforward tests, among them that starlight close to the sun's rim would be seen to bend during a total eclipse. In 1919, just such an eclipse was carefully photographed by Arthur Stanley Eddington, not yet the dean of British astrophysics. The photos showed that the stars closet to the sun had shifted a small but measurable degree, and the world was never quite the same thereafter. (When later asked what he'd have done if the photos had shown anything else, Einstein said, "I'd have been sorry for the Good Lord Almighty.")
There exists today a large and growing class of theories on subjects that are either too vast, too small, too remote, or too complex to allow adequate testing. These include such abstruse concepts as string theory, brane theory, and dark matter. So critical has the situation become in some fields that there has been talk of "the end of physics", or even the end of science as a whole - surely a premature diagnosis.
Among all the cutting-edge ideas not susceptible to testing there's one that's quite familiar - global warming. The earth's climate, we're told, is far too large and complex (in both the mathematical and common meanings) a phenomenon to be subject to any conceivable form of testing. All the same, the dangers presented by climate change are so great that we cannot wait for actual evidence. The risk is infinite, so we have to act now, while there's still time.
But is that in fact the case? It's quite true that a planetary climatic system exceeds any test that we can design. The best we can do is model it, through computer simulations that are by their very nature incomplete (not to mention contradictory). Wouldn't it be nice if we had access to some natural example comparable to what's occurring now, so that we could analyze it and get some idea of what we're facing?
It so happens that we have exactly that. This isn't the first time warming has occurred on earth - it's a commonplace and recurring phenomenon. As we've seen previously, one such episode took place in relatively recent historic time - the Little Climatic Optimum, better known as the Medieval Warming Period. During the LCO, worldwide temperatures rose by 1 to 3 degrees centigrade for a roughly three-hundred-year period beginning in the 10th century and ending late in the 13th century. Records from the era are abundant and easily available.
Warming advocates have made a series of predictions concerning climatic effects over the coming century. Do they pass the LCO test?
Sea Level Rise
This is one of the most popular topics among global warming advocates, probably because it lends itself to spectacular visuals: maps of Florida "after the warming" are commonplace, while the honest and well-researched film An Inconvenient Truth features scenes of an underwater New York City. Speculations as to the height of the inundation vary from roughly a meter in the 2000 IPCC report to twenty feet from filmmaker Al Gore to double that from Australian activist Tim Flannery.
And during the LCO? Over three centuries, the highest oceanic level was eighteen inches above the previous norm. That foot-and-a-half may sound like quite a lot, but the damage it caused appears to be minimal. There are no records of massive flooding either in Europe or elsewhere. No seacoast villages were relocated that we know of. Florida was certainly not overwhelmed.
It may only be a coincidence that the IPCC's new report has halved its estimate of sea level rise to the same range as occurred during the LCO. While such a rise may cause some problems, it is not Noah's Flood, and shouldn't be treated as such.
A related matter, one that plays very well in places like Hawaii, involves fears that beaches worldwide will be swept away in the deluge. This appears to be based solely on the experience of Tuvalu. A small cluster of atolls in the South Pacific about 600 miles north of Fiji, Tuvalu (formerly the Ellice Islands) was widely featured in the news a few years ago due to claims that it was being "washed away" by rising sea levels. Suggestions were made that the entire population of 11,000 be settled elsewhere. Grim lessons for seacoast communities were drawn.
It developed that Tuvalu's beach erosion was caused by overbuilding. Putting too many houses on a beach upsets shoreline dynamics, literally pushing sand out to sea (the same phenomenon can be found all up and down the New Jersey shore). Tuvalu has not been evacuated and, if its web site http:// can be trusted, has just elected a new prime minister.
What does the LCO tell us about beach erosion? For that we can turn to the Furdustrand, literally, "wonder strand", so named by the Vikings who were the first Europeans to come across it about A.D. 1000. The Furdustrand, a white-sand beach close to forty miles long and in places 200 feet wide, is in truth spectacular, and would be a lot more widely known if it was anywhere on earth more accessible than Labrador.
The point is that Furdustrand today looks exactly the way it did when the Vikings first grounded their ships on its sands. The rising sea levels of the LCO, the retreating levels of the Little Ice Age, and the return to higher levels since 1850 appear not to have harmed it one iota. Fears of disappearing beaches can be dismissed.
The idea that coral reefs will be wiped out by global warming is an oddity, thriving as coral does in the warm waters of the tropics. The best known is the Great Barrier Reef off Australia's tropical northeastern coast, and of course, the entire South Pacific is dotted with atolls that began their careers as exactly such reefs. (Tuvalu itself is comprised of several coral atolls.) You will look long and hard for any such islands in the cold waters of the Arctic or the Southern Ocean.
For some years, large stretches of coral in the world's oceans have suffered "bleaching" as the living coral dies and leaves only the basic skeletal structure. The contention that warming is to blame appears to arise solely because it's happening at the same moment: the earth is warming, coral is dying, therefore, warming is killing the coral.
But the same coral reefs existed during the LCO, and appear not to have been affected by the large-scale warming that occurred at the time. There are no beds of dead ancient coral visible, no legends of mass die-offs by Melanesians or other native peoples (dying coral would have deprived fish of a safe environment, leading to a drop in the food supply). We have to conclude that no such thing happened.
And in fact, recent research has clearly demonstrated that sewage runoff is the actual culprit, poisoning reefs off both Australia and the United States. Runoff of fertilizer, pesticides, and other chemicals may also have an adverse effect.
It comes as no surprise to note that many environmentalists are attacking sewage dumping while still playing the warming angle.
Mass extinction is another favorite of warming advocates, with figures of up to "one-quarter" to "one-half" of all species disappearing, though there's no concrete evidence of a single species actually being threatened by warmer temperatures. As with much warming rhetoric, this seems to be sheer speculation, based on the premise that certain "niche" organisms will die out as their marginal environments are changed.
The problem with this thesis is that no species appears to have vanished as a result of the LCO. While it's certainly possible that a marginal species limited to a single locale might have suffered, the simple assumption cannot be made. Certainly no massive die-off as predicted by the more hysterical Greens and their media allies ever took place. Warming and cooling has occurred continually throughout the geological history of the planet earth. It's safe to assume that most organisms have developed means of dealing with them.
Severe storms are mentioned for pro forma reasons as much as anything. We're all aware (much as the media has chosen to neglect the fact) that last fall's hurricane season, predicted to be second only to the Day of Wrath in violence, was a complete washout, with not a single serious hurricane troubling American shores. This was a grave disappointment to Greens after 2005's wild roller coaster ride.
The run amok storm thesis is a result of junior high science: the atmosphere is a heat engine, so if you add more heat, there will be more activity, with storms growing in frequency, duration, and violence with no perceptible upper limit. (At least two disaster novels have already been written using this premise, both of them truly lousy, so don't even think about it.) In truth, most warming occurs at higher latitudes, effectively erasing differences in atmospheric temperature and meliorating weather.
This is clearly seen in the LCO, a period of generally calm and predictable weather, with lengthy summers, gentle winters, and fierce storms relatively rare and all the more striking for that. This calm literally lasted for centuries, enabling the Vikings to carry out their explorations in open boats at very high latitudes, areas afflicted with horrible weather even to this day. Numerous violent storms reappeared when the climate cooled in the late 13th century, with terrifying results. Consider the fate of Winchelsea, an English port swallowed by the waves of the Channel during a days-long rainstorm in 1297. Even worse were crop failures caused by dismal weather all across Europe that resulted in repeated general famines. Clearly it's cooling that leads to foul weather. Which may prompt us to wonder exactly what's behind the past few weeks' spate of killer blizzards.
Melting Ice Sheets
The melting of the world's major ice sheets - those of Greenland and Antarctica - is nearly pure fantasy. It would take a millennium of continuous hot weather to make a dent in either. Certainly the LCO, which lasted a little over three centuries, failed to leave much of a mark.
It's possible that warming may actually add to the thickness of the continental ice sheets by increasing evaporation, which then falls as snow. This seems to be happening to both ice sheets. Is this part of a planetary homeostatic system that keeps things in rough balance? We simply don't know. Perhaps James Lovelock can ask Gaia about it.
(For what it's worth, Iceland has seen a lot more pack ice this winter in its western fjords - those opposite Greenland - than for many years previously.)
Warming is predicted to bring about a vast increase in disease, particularly tropical diseases taking advantage of newly-opened ecological niches - yaws in the Midwest, hookworm in Nova Scotia, altogether an ugly picture. (Some claims have been made that this has already occurred. A sometimes deadly tropical fungus has apparently transplanted itself to Vancouver Island, with global warming to blame. It's difficult to see what the mechanism for this could have been, unless the fungus is capable of reading the IPCC report. Certainly there's no reason to believe that Western Canada has suddenly turned tropical. It is, like nearby Washington state, one of the wettest areas in North America, making it homey for any number of fungal diseases, which could have easily hitched a ride on any ship or aircraft heading north.)
What's the testimony of the LCO? While by no means disease-free, the medieval warming period was as close to it as any era before the pre-modern world can show. The black plague, the chief dread of the period, completely retreated from Europe to its original home in central Asia (evidently, rodents in the Caucasus have adapted to the plague bacillus and serve as a steady, living reservoir). There are no outbreaks of plague on record during the LCO and few of other diseases. This was the direct result of a combination of gentle weather and good harvests - well-fed people tend to have robust immune systems.
It could be argued that the modern era is different, with cheap jet travel allowing easy and quick transmission of disease, as we saw with the SARS outbreak in 2003, which leapt from China to Toronto in a matter of days.
But in truth, movement during the LCO was considerably freer than in many later eras (the late 13th century was Marco Polo's epoch). Along with the Vikings, there are the Mongols, who burst into Europe just before the era drew to a close. A curious fact about these episodes is that they were not followed by massive exchanges of diseases, which normally occurs when cultural bubbles are broken after long periods of isolation. (Consider the varied and deadly plagues that killed much of the native population of Mexico after the Spanish invasion.) Whether this is due to the influence of the LCO is impossible to surmise, but it's a telling sign.
Destruction of the Economy
It's difficult to discern the exact nature of the purported relationship between warming and economic performance, and Green rhetoric offers little assistance. I would guess that the specter of a crashed economy is simply added on as a matter of course, as a kind of Fifth Horseman armed with pink slips and foreclosure notices rather than scythes or swords. Certainly there's nothing inherent in any warming scenario that would lead to the economy going south. It must be all those plagues and storms.
It's not easy to compare a modern economy with that of the feudal epoch, except to say that the LCO appears to have encompassed an era of general good fortune. A peasant culture requires little more than plentiful food and roofs that don't leak, and the LCO had both.
That ended when the cooling came, at the close of the 13th century. The encroaching cold was accompanied by the medieval depression, which lasted for over two centuries. (Consider the 1930s in light of that.) The trigger was declining harvests and the plagues that followed. All of which suggests that we should hope for warmer weather, if anything. Bulls are associated with hotter climates, while bears don't mind the cold.
Comparisons to the LCO are certainly not kind to the global warming thesis. In an earlier day, we'd have patted the advocates on the shoulder, handed them a calculator, and told them to start over. But these, of course, are not ordinary times.
A close study of the LCO would prove valuable, not only as regards warming but as an example of human beings living in an environment subtly but definitely different from the one we're used to. But don't expect it anytime soon. The debate, we're told, is over, and the cost of understanding has gotten very high.
J.R. Dunn is a frequent contributor to American Thinker.