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

Ian Dunlop: an emergency war footing action against climate change

Ian Dunlop, is an energy expert, director of "Australia 21," member of the Club of Rome, and more. On climate change, he is an extremely effective speaker who doesn't do any pill sugaring; as you can see in the video above. The slides he presents are also avaliable on-line. From this set of slides, here is the conclusion:

The climate & energy challenge is far greater & more urgent than is acknowledged officially

“Official” solutions, and current processes, are not working and will not deliver the required transformation either to the extent, or in the time, required.

Market forces will not deliver without fundamental regulatory change.

If we are serious about avoiding catastrophic outcomes, emergency “war-footing” action is essential


“It is no use saying ‘we are doing our best’, we have to do what is required.” 

Winston Churchill

Communicating climate change in ONE graph

It is sometimes said, that one (good) picture is worth of thousand words. Let's try to do that experiment. Let us have the instrumental temperature record since 1880 till present, coupled with paleoreconstructions of global temperatures using various "proxies" during the last 540 millions years, and add to that the boiling-frog (i.e. business-as-usual) scenario with policy unrestricted GHGs emissions:

*This graph show the reconstructions of global temperature during the last 542 millions years, together worst case temperature rise by the end of this century following the 8.5 RCP (Representative Concentration Pathway) scenario (van Vuuren et al., 2011). 8.5 is amount of additional radiative forcing (in W/m2) relative to the preindustrial period. Global temperature rise of » 4,7°C (8,5°F) is taken from the latest draft report of U.S. Global Change Research Program (p33, PDF). Also note that the scale of x-axis is varying, and that such rapid current+projected temperature rise did not occur during this period. Source of the graph: Wikipedia.

Thus even if we consider large uncertainties of the paleoclimatic temperature record, going anywhere close to the “worst case” scenario would, in the long term, completely deglaciate our planet. Climate change itself would probably not allow such dramatic rise of global temperature, not seen for tens of millions of years, but this is clearly something we would collectively like to avoid. 


A comment by Ugo Bardi:  This post by Alexander Ac is a good example of the subject of this blog. We are trying to "package" the information on climate change in ways that are not only understandable, but also direct and effective. This "one graph" summary of climate change goes in the right direction, but I would like to add a caveat. 

We shouldn't forget that most people, out there, are not able to read even simple x-y graphs. This specific graph, with a variable x scale, is not easy to read and will be confusing for people who never learned the specific "graph language" that scientists find so obvious. Still, this graph may be a winning weapon to penetrate the "climate illiteracy" that affects a good number of scientists and professionals who are not specialists in climate.