Se “Armi, Acciaio e Malattie” di Jared Diamond era un tentativo, riuscito, di spiegare l’influenza fondamentale della geografia sulla storia umana, The Long Summer di Brian Fagan segue un percorso analogo, in una sorta di sequel che si concentra sugli aspetti climatici.
Secondo l’autore il clima è una causa tanto importante quanto trascurata di molti rivolgimenti storici. È sulla spinta dei cambiamenti climatici che gli uomini hanno traversato, nel corso dei millenni, l’Europa e le steppe della Siberia, per poi arrivare in America. Il clima ha spinto l’umanità a modificare il proprio stile di vita, spingendola verso l’agricoltura e l’abbandono della condizione di cacciatori-raccoglitori. Al tempo stesso i cambiamenti climatici hanno determinato, attraverso inondazioni e siccità, il crollo di regni ed imperi: dagli Ittiti ai Maya, dall’Egitto all’antica Roma, intere civiltà sono state messe in ginocchio dalle bizze del clima.
Il libro non si limita a guardare indietro, però. In tempi di riscaldamento globale e cambiamenti seguenti, l’autore è molto scettico sulla capacità di adattarsi della nostra civiltà:
“Climate has helped civilization, but not by being benign. The unpredictable whims of the Holocene stressed human societies and forced them to either adapt or perish[…]The collapse often came as a complete surprise to rulers and elites who believed in royal infallibility and espoused rigid ideologies of power.
There is no reason to assume that we’ve somehow escaped this shaping process. Agriculture is less visible to us now – the number of people growing food has shrunk from 90 percent of labour force in Europe five hundred years ago to less than 3 percent in the US today – but we still need to eat. And now our vulnerability extends far beyond just growing food: our crowded coastlines with densely packed high-rises and apartment of finance and scholarship and entertainment, are beholden to the world’s climate in ways both obvious and hidden. Like many civilizations before us, we’ve simply traded up in scale, accepting vulnerability to the big, rare disaster in exchange for a better ability to handle the smaller, more common stresses, such as short term droughts and exceptionally rainy years.
But if we’ve become a supertanker among human societies, it’s an oddly inattentive one. Only a tiny fraction of the people on board are engaged with tending the engines. The rest are buying and selling goods among themselves, entertaining each other or studying the sky or the hydrodynamics of the hull. Those on the bridge have no charts or weather forecast and cannot even agree that they are needed; indeed, the most powerful among them subscribe to a theory that says storms don’t exist, or if they do, their effects are entirely benign, and the steepening swells and fleeing albatrosses can only be taken as a sign of divine favor. Few of those in command believe the gathering clouds have any relation to their fate or are concerned that there are lifeboats for only one in ten passengers. And no one dares to whisper in the helmsman’s ear that he might consider turning the wheel.”
Troppo pessimista? Leggete il parere del buon Brian su New Orleans:
“The battle to control the river never ceases, for a breach upstream is always possible and the awesome power of of the flooding water can break out anywhere. For the moment, the Corps believes the river is contained. But given the right combination of heavy snow and much higher than average rainfall, there is a real chance that the Mississipi will follow its own will and shift course to the Atchafalaya, as it obviously wants to do[…]Today the fate of a city of a million people and many billions of dollars of infrastructure depends on our control of half a continent’s worth of increasingly restless river water. New Orleans is safe against the flood that comes once every hundred years. As for the thousand-year flood or the ten thousand-year flood or the ten-thousand-year one, we can only hope for the best”
Il libro è uscito a fine 2004, Katrina arriverà pochi mesi dopo: e se per una volta ascoltassimo Cassandra?...Continua