There was no warning of the catastrophe. In early January 1709, the worst cold spell to hit Europe in 500 years reigned down unexpectedly on people and animals, bringing about devastation. Throughout the continent, from Norway to Italy and from Romania to France, rivers froze, seas caught ice, animals died in their barns and unfortunate travelers froze to death mid-way, in their clothes. Over the next two weeks, Paris, the largest city at the time, reported over 24,000 of its citizens dead, after massive crop failures and the freezing of the Seine river, which flows through the city.
Though the freeze lasted only three months, it was enough to cause the death of all harvests planted the year before, and therefore triggered a significant chain of events that culminated in widespread famine and rioting over food, which was at the time in very short supply. Animals also died from the cold, even if the farmers made fire near them every night. Soils froze up to an unprecedented depth of 1 meter, or even more, which meant that even some trees suffered the effect of the harsh cold spell.
On the 10th of January 1709, temperatures recorded in Paris were as low as minus 14 degrees Celsius (6.8 degrees Fahrenheit), which proved to be the lowest ever recorded by any meteorologist in Europe by that time. Even royalty had a difficult time keeping warm. The French court, the most sumptuous in the world, remained indoors throughout this period, and struggled with chilly temperatures the best they could.
"I am sitting by a roaring fire, have a screen before the door, which is closed, so that I can sit here with a sable fur piece around my neck and my feet in a bearskin sack and I am still shivering with cold and can barely hold the pen. Never in my life have I seen a winter such as this one," the Duchess of Orleans wrote to her aunt, who was in Germany.
"Travelers died in the countryside, livestock in the stables, wild animals in the woods; nearly all the birds died, wine froze in barrels and public fires were lit to warm the poor," reads a canon from Beaune, in Burgundy, France.
"Something unusual seems to have been happening. With daily data you can produce very reliable monthly averages but you can also see what happened from one day to the next. This is a key climatic zone. The weather there reflects wider conditions across the Atlantic, which is where in normal circumstances much European weather originates," says University of Sunderland climatologist, Dennis Wheeler, who has with colleagues compiled an extensive database of that time frame, stretching as far back as 1685.
"We need to explain the natural variation in climate over past centuries so that we can tease apart all those factors that contribute to climate change. But before we can do that we need to nail down those changes in detail," he says.
"Climate doesn't behave consistently and warmer and colder, drier and wetter periods can't always be explained by the same mechanisms. Some people point to that and say today's warming is nothing new. But they are not comparable. The factors causing warming then were quite different from those operating now," concludes the researcher.