18 Miles

by Christopher Dewdney

  The fact is weather never exceeds the bounds of climate; it is a subset of climate, a particularity. You could say that weather is the quotidian particulars of climate. The difference between the two is primarily time based. Weather has short duration, hours usually, days occasionally, sometimes weeks, and even, when a big volcano erupts, years. Climate takes decades and more often centuries.

  Climate change has had extraordinary effects on human civilization over the last 10,000 years. It induced a famine that racked Egypt 4,200 years ago. It caused the desertification of the American southwest 800 years ago, which forced the Ancestral Puebloans from their elegant cliff cities. At the beginning of the Little Ice Age, 500 years ago, fickle monsoon rains collapsed the great civilization of Angkor Wat in Cambodia while, on the opposite side of the planet, the Viking settlements were frozen out of Greenland.

  There was a cultural upside to the Little Ice Age though. The legendary sound of Stradivarius’s violins owe much of their tonality to the 400-year-long cold snap. Why? Because Stradivarius used Croation maple wood for the neck and back of his instruments, and the particularly severe winters of the Little Ice Age slowed the maple’s growth and compacted its wood. The long, icy winters in the mountains of Croatia imparted a unique, ethereal tone to the Stradivarius violin. Certainly climate change and decades-long droughts have changed human destiny. But history has also been changed by just plain weather, and sometimes much more profoundly than climate.

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  Weather That Changed History

  “Fortune, which has a great deal of power in other matters but especially in war, can bring about changes in a situation through very slight forces.”

  Julius Caesar

  Never does the fate of a nation hang in the balance so delicately as during a pitched battle for its very survival, and, on a surprising number of occasions, weather has tipped the scales in favor of one side or the other. Weather was certainly the deciding factor in the fifth century BCE, when the Persians invaded Greece.

  King Darius (550–486 BCE), the third king of the Persian Achaemenid empire, ruled at the peak of its power. His realm stretched from present-day Turkey in the west to the border of India in the east and from the Black and Ural seas in the north through the whole of the Middle East to Egypt in the south. It was on his watch that the Achaemenid empire began to annex Greek colonies, most notably in Ionia. But the Greeks did not take well to occupation.

  A series of rebellions ensued, inflicting so much damage on Persian forces that in 490 BCE King Darius ordered the invasion of Greece proper. He assembled an army of 10,000 immortals (elite infantry), 10,000 light infantry, 5,000 archers, 3,000 cavalry and 600 naval vessels (triremes) and placed them under the command of his best generals, Datis and Artaphernes.

  The Persians razed the island of Naxos and then landed on the Greek mainland where they besieged and destroyed Eretria. They then headed to Marathon. But here the Greeks took a stand. Miltiades, the Greek general, had only 9,000 Athenians and 1,000 Plataeans against the entire Persian army, and yet by the end of the day the Persians were routed, losing more than 5,000 soldiers. By contrast, Athenian and Plataean casualties numbered less than 2,000.

  The victory at Marathon was a huge morale boost for the Athenians, especially since they had achieved it without Spartan help. For his part, King Darius swore to revenge this humiliating defeat, and the Persians withdrew in order to draw up new invasion plans. But King Darius died four years after the battle of Marathon and it fell to his son Xerxes to uphold his father’s pledge. Xerxes invaded Greece in 480 BCE with a huge force. According to modern estimates, his army alone totaled somewhere in the neighborhood of 100,000 to 150,000 soldiers against an accumulated Greek standing army of about 52,000 souls.

  Themistocles, the Athenian politician and naval strategist, was the general in charge of the Greek defense. His battle plan was to bottleneck the Persian invasion on land at Thermopylae and on water at the Straits of Artemisium. Both battles were stopgap measures, meant to hold off the Persians rather than defeat them. Here is where the weather comes in.

  Several days before the great naval engagement in Artemisium, which historians believe took place sometime in August or September 480 BCE, the Persian fleet was caught in a terrific gale off the coast of Magnesia near Thessaly. Four hundred of their 1,200 triremes sank, a staggering loss. (Persian triremes were not inconsequential vessels. Like the Greek triremes, they had been perfected over hundreds of years of naval warfare and each 40-ton trireme was more than 120 feet long with 120 oarsmen.) Yet, with 800 triremes left, the Persians still had a massive logistical advantage. Their commander ordered 200 vessels to sail around the coast of Euboea in a maneuver to entrap the Greek navy, but against all odds another storm struck, and all 200 were shipwrecked. The Persians had lost half their fleet to bad weather.

  Even this monumental loss wasn’t enough to save the Greek fleet. A few days later the two navies met at Artemisium, and the odds were still in favor of the Persians. The 270 ships that the Greeks mustered were vastly outnumbered, and in the ensuing fray both navies lost a hundred vessels. The Greeks retreated with the remainder of their fleet.

  Meanwhile, as the Greek and Persian ships clashed on the seas, a historic battle was taking place on land at Thermopylae. This time the Spartans had decided to join the fray. A Greek force of about 7,000 soldiers led by the Spartan king Leonidas held off the entire Persian army on Thermopylae’s narrow strip of coast. The battle would have been a stalemate had not a local resident named Ephialtes betrayed Leonidas by disclosing the location of a secret path that led behind Greek lines. When Leonidas got wind of the treason, he realized his position was hopeless. He dismissed most of the army and remained with a diversionary force of 300 Spartans, 700 Thespians and 400 Thebans. This final, desperate battle became legendary. By the time the last Spartan fell, the Persians had lost 20,000 men.

  After their costly victories in Greece, much of the Persian army withdrew to Asia. Xerxes left behind his trusted general, Mardonius, to complete the conquest with a smaller force. Mardonius’s army went on to sack Athens (which had been evacuated), while on the Aegean Sea the Persian navy chased the Greek ships until, late in the autumn of 480 BCE, they cornered the Greeks in the straits at Salamis. But this was a trap that would backfire for the Persians. Themistocles knew these waters well, and he knew the autumn weather even better. He had a meteorological trick up his sleeve.

  Having no inkling of Themistocles’s hidden ace, the Persian commander presumed that, with his 500 triremes to the Greeks’ 370, he had effectively trapped and outnumbered them. The Greek vessels were on the other side of a headland from the Persians, not in direct line of sight. At sunrise on the day of battle, there were so many Persian boats they formed a solid line across the straits, blocking any chance of escape for the Greeks. The Persians waited, knowing the Greeks would never offer terms. Yet the morning wore on. Uncharacteristically, or so it must have seemed from the vantage of the Persians, Themistocles delayed action until mid-morning, when he sent out a handful of his ships. Instead of engaging the enemy, however, the Greeks turned and retreated to their redoubt. The Persians took the bait, and the entire fleet rowed into the narrow waters of the strait. They had no idea that the wind god Aeolus was about to enter the fray on the side of the Greeks.

  As soon as the Persians rounded the headland, the Greeks launched their assault, ramming the Persian triremes with deadly accuracy. Several Persian vessels began sinking and chaos ensued — too many boats crammed in too small a space. Right on schedule, the late morning Etesian wind arrived, blowing the top-heavy Persian ships against each other and creating a tangle of boats. The Greeks were able to outmaneuver and sink more than half the Persian fleet before it retreated in complete disarray.

  It was the beginning of the end for the Persian campaign. The Persian army remained in Greece for another year before it was defeated at the battle of Plataea in A
ugust 479 BCE. Almost simultaneously, the vestiges of the Persian navy were crushed at the naval battle of Mycale.

  The battle of Salamis turned out to be the turning point of the war, and the Persian navy never regained its former strength. If not for the dependable Etesian wind, Greece’s great classical age would have been stillborn, and the course of Western civilization irrevocably altered.

  The Fall of Dacia

  “Extraordinary rains pretty generally fall after great battles; whether it be that some divine power thus washes and cleanses the polluted earth with showers from above, or that moist and heavy evaporations, steaming forth from the blood and corruption, thicken the air.”

  Plutarch

  Domitian, who ruled Rome from 81 to 96 CE, oversaw the empire at the height of its power and territory. A ruthless, despotic tyrant, he was nonetheless popular with the legions after he led several successful campaigns in Britain. Yet he was never able to tame the Dacians, who maintained a huge territory (approximately the area now occupied by Romania and Bulgaria) less than 700 miles from Rome. They were constantly harassing Roman settlements. In 85 CE, they invaded the Roman province of Moesia and killed the governor, Oppius Sabinus. The Romans beat them back, but in 86 CE they invaded again. This time, Domitian sent a legion commanded by the Praetorian prefect Cornelius Fuscus. The two forces met at Tapae in a battle that ended with a humiliating defeat for the Romans. An entire legion was wiped out. Prefect Fuscus was killed, and the Dacians captured the Roman battle standard, or aquila.

  While Rome could countenance a military defeat, which was sometimes unavoidable, the loss of their standard was too much. Domitian petitioned the senate to renew the campaign against the Dacians, but, like Darius before him, he didn’t live to see Roman revenge. On September 18, 96 CE, he was assassinated, and it fell to the next emperor, Trajan, to get the job done.

  Dacia became Trajan’s personal vendetta and he invaded it in 101 at the command of two legions, penetrating all the way to Tapae and the same battlefield where the Romans had been defeated 15 years earlier. There he met his well-armed and formidable opponents.

  The battle went well for the Dacians at first, but then a thunderstorm swept over the combatants. The Romans saw it as a sign that Jupiter had joined the battle on their side, and they fought in the rain with renewed vigor. Unwilling to take on both Jupiter and Trajan’s legions, the Dacians retreated. The second battle of Tapae was a great success for the Romans, who then pressed their advantage north until the Dacian king, Decebalus, sued for peace. A summer storm had tipped the balance.

  Hammer of the North

  Bad weather can last for years. Such was the case in Norway, Sweden and Denmark during the sixth century when two massive volcanic eruptions caused a volcanic winter. The first is thought to be the Tierra Blanca Joven eruption in central El Salvador. Ash was carried into the upper atmosphere and then encircled the globe. In 536 CE, the year after the eruption, the Byzantine historian Procopius wrote, “During this year a most dread portent took place. For the sun gave forth its light without brightness, like the moon during this whole year, and it seemed exceedingly like the Sun in eclipse.” The second eruption happened around 539–540, probably somewhere in the tropics. The bitter decade after these eruptions was the most extreme short-term cooling event of the northern hemisphere in the last 2,000 years. There were crop failures and famines worldwide.

  Scandinavia was hit the hardest. Most of the farming villages in the Uppland region of Sweden were abandoned as the population succumbed to starvation. Similar scenes played out across the rest of Scandinavia. Those that survived did so by force, seizing the few remaining provisions at sword point. It was from this dark crucible that a new Scandinavian order arose: marauding bands of warriors, armed to the teeth, who had honed their martial skills by fighting each other for supremacy over the long, dark years. And when the summer finally returned, they took their new talent for plunder and mayhem on the road. Or, should I say, on the water. Viking longships sailed westward all the way to Newfoundland, south into the Mediterranean sea and as far east as the Volga River in Russia.

  A Russian Winter

  In the summer of 1812, Napoleon invaded Russia with some 680,000 soldiers. By September, he had taken Moscow. Eerily, the capital was deserted; there wasn’t a soul left to engage the invasion force. The Russians had evacuated the city before Napoleon entered, and they refused to sue for peace. Napoleon stayed on a month while his soldiers pillaged the burned-out ruins. In October, with a negotiated settlement out of his grasp, he began to chase the elusive Russian army southwest. That’s when the weather began to turn. It must have dawned on Napoleon, too late, that the Russians had outmaneuvered him with their stalling and evasion tactics. In November, an early and exceedingly bitter Russian winter descended in all its frosty fury.

  Temperatures dropped below -40°C. Expecting a short campaign, Napoleon’s troops had been issued no winter clothing. Furthermore Napoleon’s supply lines had been decimated by sporadic Cossack attacks, and the Russians had burned their crops to deprive the invaders of local food supplies. In one pitiless 24-hour period, 500,000 horses died from the cold. By the time his beleaguered army trudged out of Russia, Napoleon had lost 380,000 men to hypothermia and the Cossacks. One hundred thousand more had been captured. Napoleon’s failure became France’s failure, and it lost its primacy among its allies. Austria and Prussia switched sides, and the balance of power in Europe shifted dramatically.

  Who knows how European history would have played out if Napoleon’s army had not been destroyed? Had he but launched his campaign against Russia a few months earlier, the outcome would have been completely different.

  The Flanders Offensive

  By 1917, the “war to end all wars,” a conflict most military strategists thought would be over before Christmas 1914, had dragged on for three bloody years in a stalemate that cost hundreds of thousands of lives. In the spring of that year, British commander Field Marshal Earl Haig and his French counterpart, Robert Nivelle, planned a summer offensive on the German positions in Flanders. It would be a massive assault using all the technology available at the time: artillery barrages, tanks and thousands of troops. The plan was to overrun the German positions so quickly that, according to Haig, the allies would retake Belgium in three hours. They chose August to launch the campaign because it was invariably a month of dry, sunny weather in northern France. But the weather gods were not on the side of the Allies.

  On July 21, rain began to fall on the front lines. It rained again the next day, and the day after that and the day after that. It rained continuously, for the whole of August. The offensive, which began on July 31, was quickly bogged down in the mud. Even the tanks were mired, and any dreams of taking Belgium, or even the village of Passchendaele, just inside the German lines, were lost to the wettest summer Europe had seen for 30 years.

  The battlefield became a shell-blasted sea of muck where men literally drowned. There was a brief respite from the rain in September, but in October the rains began again, and Passchendaele wasn’t taken until November, 15,000 Allied casualties later. The victory, at this point, did little to change the balance of power along the front. If the August deluge hadn’t flooded the battlefield, the First World War might have ended much sooner.

  The Miracle of Dunkirk

  By the Second World War the science of meteorology was indispensable to military strategy. The famous 24-hour postponement of D-day demonstrates the power of a single forecast. Yet the vagaries of weather had other surprises for the combatants. The improvised evacuation of the British troops at Dunkirk was certainly the first of these, although in this instance it was fog and lack of wind that saved the day.

  In the spring of 1940, Hitler’s lightning-fast war overran France so quickly that more than 400,000 Allied soldiers (Belgian, Canadian, British and French) were completely encircled by German forces on the north coast of France by May 21. Their only hope was a retre
at by water. Admiral Bertram Ramsay and the leader of the British Expeditionary Force, General Gort, began to prepare a marine evacuation for the desperate troops.

  There was little time, and the situation was looking grim when, mysteriously, they were given a precious two-day reprieve. On May 24, the German High Command issued a halt order; Gerd von Rundstedt, commander for the German army in France, was concerned that his panzers and forward troops might be vulnerable to attack. Besides, Hermann Göring had argued that air power alone could destroy the retreating Allied forces. This delay was critical for the Allied evacuation plan. The weather gods were also in their corner: at the same time as the halt order, the weather took a turn for the worse. The British admiralty swung into action. Under heavy cloud cover, they sailed toward Dunkirk undetected by the Luftwaffe.

  On the afternoon of May 26, Hitler rescinded the halt order, and the German army began to advance again, but they came up against a heroic rearguard action by French and British troops. This was a diversion to give the rest of the Allied troops time to get to the beaches of Dunkirk where a sealift had already begun. The Germans were caught off guard by the evacuation. All they had at their disposal was the Luftwaffe, which harassed the Allied sealift by strafing the soldiers and bombing the ships when the weather permitted. But the RAF flew effective defensive sorties that kept the Luftwaffe from completely dominating the skies over Dunkirk.

  By the morning of May 27, the first full day of the evacuation, 28,000 men had been picked up. Many of the stranded soldiers had to wade out into the ocean to reach their rescue craft, a slow and arduous process that also made them vulnerable to the Luftwaffe’s sporadic strafing runs. But the weather continued to cooperate. The entire evacuation took place during a freakish, nine-day period of calm, cloudy weather punctuated by fog. As Admiral Ramsay reported, “It must be fully realized that a wind of any strength in the northern sector between the southwest and northeast would have made beach evacuation impossible. At no time did this happen.”