Rolf Strom-Olsen 
After the release of his documentary on global warming, An Inconvenient Truth , Al Gore was criticised by various skeptics and opponents for exaggerating the impact of climate change and especially the speed with which it might occur. The film suggests, inter alia, that the melting of the Greenland ice sheet  could be accelerated by the consequences of its own disappearance, a so-called positive feedback loop. This in turn will raise ocean levels, change the Gulf Stream and the North Atlantic Drift , causing havoc, deep freeze and general cataclysm. Various critics have dismissed or qualified these assertions (a non-polemical overview is here ), attacks which have perhaps been vitiated by the various awards garnered by both the film and Gore himself (including, of course, the Nobel Peace Prize).
I am not a climatologist and so won’t weigh in on that particular question, but the projections made in the film raise an interesting historical question: how does society adapt to rapid change? Last month, the Economist published a very interesting article  on the rapid and extraordinary impact of an acidic cloud emanating from an Icelandoc volcano, which erupted in 1783. Within weeks of the event, a toxic fog had descended upon much of Europe, and was felt as far away as Japan and the Mississippi. The consequences were immediate and deadly: crops failed, food shortages were widespread and mortality rates surged. It turned out to be the first in a set of disappointing harvest years in Europe; within a decade, hungry French farming families had helped turn politics on its head by removing that of their King. Although the climatic events of 1783 were unrelated to global warming, the take-away message is the speed with which such changes have both a direct impact on and longer-term consequences for our social system.
Similarly monumental effects on society have been felt elsewhere across our history. The Black Death or Bubonic Plague pandemic swept through Europe in 1348-1350. Almost seven hundred years later, historians are still arguing  about the net consequences of that event, which reduced the European population generally by over a third, and in some places by well over half. At a minimum, most historians attribute the end of the feudal economy, the weakening of the Church, and a rise in social mobility to the resulting demographic shift that occurred. Some (like me) also trace the beginnings of the Reformation to this event. Others have suggested that this collective shock produced the Renaissance, the post-feudal state, and even the early capitalist system.
Where the Black Death led to reduced competition for resources, the current convergence of trends is producing the reverse. Whether the incipient revolution in energy use (cf. peak oil ), agricultural crises (and take your pick – banana blight , Colony Collapse Disorder  (articulo en español ), or the imminent collapse of the world’s fisheries ), or climate change, we seem to be on the brink of dealing with major changes in our world. Additionally, the rise in global wealth is producing greater competition for resources, driving up prices and changing our consumption habits. This will undoubtedly produce a raft of effects that we can only vaguely discern.
We thus face the prospects of rapid change induced by two unrelated but convergent phenomena. A rapid rise in wealth, akin to that unleashed by the demographic ravages of the plague which enriched the survivors. This will add further to the pressures on the world’s supply of food, minerals and other resources. And a potentially sudden shift in our environment, such as that spawned by in 1783, which could reduce the ability of our planet to provide for our needs. Who knows what the changes in our society will look like as a result, but even the merest glimpse at our own history teaches us that such transformations are likely to be swift, profound and indelible.