TESTING GLOBAL WARMING

Science works by means of prediction on the basis of testing a hypothesis. 

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.

Yet it is claimed that the hypothesis of man-made ("anthropogenic") global warming cannot be tested.  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, then, 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.  One such episode took place in relatively recent historic time – the Medieval Warm Period.

During the MWP, worldwide temperatures rose by 1 to 3 degrees centigrade for a roughly three-hundred-year period beginning in the 10^th century and ending late in the 13^th century.

Records from the era are abundant and easily available.  See Jack Wheeler's Solar Warming for charts.

Warming advocates have made a series of predictions concerning climatic effects over the coming century. Do they pass the MWP 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 Algore's 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 Algore to double that from Australian activist Tim Flannery.

And during the MWP? 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 MWP. While such a rise may cause some problems, it is not Noah's Flood, and shouldn't be treated as such.

Eroding Beaches
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. A perusal of the Tuvalu government website shows the place is doing fine, having just elected a new prime minister, Apisai Ielemia.

What does the MWP tell us about beach erosion? For that we can turn to the Furdustrand, literally "Wonderstrand," so named by the Vikings who were the first Europeans to come across it about A.D. 1000. The Wonderstrand, 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 northern Labrador.

If you'd like to vacation there, Experience Labrador will be happy to arrange it.

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 MWP, 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.

Coral Reefs
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 off Antarctica.

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 MWP, 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 Australia, Florida, and Caribbean islands . 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.

Animal Extinction
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 MWP. 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.

Increasing Storms
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.

In truth, most warming occurs at higher latitudes, effectively erasing differences in atmospheric temperature and meliorating weather.

This is clearly seen in the MWP, 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 13^th 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 MWP, 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.)           

Disease
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 in Canada's British Columbia, with global warming to blame.

It's difficult to see what the mechanism for this could have been. 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 MWP? 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 MWP 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 MWP was considerably freer than in many later eras (the late 13^th 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 alien invasions 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 MWP 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. Perhaps 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 MWP 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 MWP had both.
That ended when the MWP ended and the cooling came at the close of the 13^th 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.

The conclusion to draw from all of the above:  we should hope for warmer weather, not colder.

Comparisons to the MWP 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 MWP 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.

Professor David Deming, a geophysicist at the University of Oklahoma's College of Earth and Energy, testified at a Senate hearing that a "major researcher in climate change" warned him:  "We have to get rid of the Medieval Warm Period."

Now we know why.  The MWP disproves the disaster predictions of the man-made global warming hypothesis.