Strategies of Communication on Climate Change

Sunday, June 30, 2013

Climate change: not just a question of the past 15 years.



Recently, it has become fashionable to say that climate change is not a problem (or even that it doesn't exist) because the past 15 years haven't seen a heating of the atmosphere so fast as it used to be the rule. Well, climate change is not just a question of the past 15 years, as Steph explains here discussing the conditions of the Alps at the time of the Carthaginian General Hannibal (Image from AncientWeb.org)

The Alps over time: Hannibal

by Steph.

During the Second Punic War, in September 218, the Carthaginian general Hannibal crossed the Montgenevre pass on the Alps with 20,000 infantry, 6,000 cavalry and 21 elephants. Only half of the army that had started from Spain (90,000 infantry, 12,000 cavalry and 37 elephants) with the aim first to ally with the Gauls and then off to Italy to clash with the Roman armies. But Hannibal made an error of judgment because the Gallic tribes were generally hostile to him unless the king of the Boi, Magilo who helped him to cross the Alps. It was a grueling journey that took the lives of many soldiers. In addition the Carthaginians had to face the harsh winter of the Po Valley and according to Polybius only an elephant survived its rigors.

The Greek historian gives us his account of that event:

Troughout the lowland regions, Hannibal arrived at the foot of the Alps. At the front, there were the elephants (...) the enemies, who had never seen those animals, did not dare to approach. (...) When they reached the pass, Hannibal ordered a stop (...). At dawn (...) the march was resumed, but the descent proved more difficult than the ascent. During the night, snow had fallen and the column moved slowly. Down the steep trails, men and horses slid, falling over each other, barely restrained by shrubs and roots protruding here and there. The passage of so many men and animals turned into soft mush the thin layer of fresh snow, exposing the underlying ice (...).


In September, new snow on the ice below at 1800 m above sea level?? ... what year was this one that Hannibal chose? Where can you find, today, glaciers at 1800 m on the western Alps? Nowhere, I think.

In short: it is the curse of Ötzi (and not just that). The most recent reconstructions (see also here); less recent ones, and even Polybius, remind us that for more than 5000 years in the past the Alps never were so hot as they are today. Perhaps never so hot from the time of the last interglacial. Take into account the fact that the glaciers are not in equilibrium with current climate conditions and if they were, they would shrink even more: it's only a matter of decades.


So, if some people are so impressed that during the past 15 years the surface temperatures didn't rise so much, think of how much they changed from the times of Hannibal. And how much they still have to change in the future.

Here are some data about temperatures in the Alpine region in Europe




Büntgen et al. 2011



Büntgen et al. 2006




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