Many in the climate/sustainability world are understandably preoccupied with the notion of collapse. After all, it is reasonably argued that if we do not change the course of our civilization then collapse is inevitable. This is undoubtedly true, as any civilization that is not sustainable must either change and become sustainable or face an ever-increasing frequency of daunting challenges. For a time, at least, such a civilization can overcome challenges by a combination of skill and luck. But eventually either skill or luck (or perhaps both) will run out.
Our civilization is unsustainable. Massively so.
But while in theory the reasons why a civilization collapses are simple, in practice nailing down the reasons why and applying the lessons of past civilizations to our current predicament is anything but simple.
Greenland: A new emerging picture
For example according to conventional wisdom the Norse civilization in Greenland collapsed because they failed to adapt to the harsh climate. While the neighbouring Inuit civilization, which did not suffer a collapse, relied on mobile hunting strategies that maximised the abundant marine resources around Greenland, the Norse refused to abandon their agrarian traditions which had served them well for generations further south in temperate regions. But this agrarian based civilization was poorly suited to the harsh climate of Greenland and thus it didn’t take much to push the Norse towards collapse.
At least that is what the conventional wisdom tells us. Speaking at last months AAAS annual meeting in Vancouver, Andrew Dugmore of the university of Edinburgh described how recent evidence is raising strong doubts about the conventional wisdom on the Norse in Greenland and the implications of this new understanding raises troubling implications for the resilience of modern civilization.
Rather than adhering to a rigid agrarian civilization that was out of place in the Arctic, the Norse adapted quickly to the difficult climate of Greenland. While not giving up entirely on their agrarian tradition they quickly began to exploit the abundant marine resources that surrounded them.
Thanks to the short summers of the arctic, Norse farms in Greenland could not produce enough food to sustain the population through the long arctic winter. In order to survive they supplemented their food supply with a large hunt of the many harp and hooded seals that migrate along the coast of Greenland in the spring. Due to various environmental factors, fish never became a staple food as it did in other Norse settlements further south.
As time progressed and the unpredictable nature of the Arctic climate began to take it’s toll on the ability of the Norse to maintain sufficient production levels on their farms, their reliance on the seal hunt intensified. This increased reliance on the seal hunt allowed some Norse settlements to survive some large scale decadal variations in climate, but it sowed the seeds of their eventual collapse.
Over time the seal hunt became absolutely essential, and during the 15th century a combination of cold and stormy conditions severally restricted the ability of the Norse to hunt for the harp and hooded seal they depended on. It is worth noting that the cold and stormy conditions were not unprecedented, but combined they presented a serious challenge to the settlers’ ability to hunt seals in sufficient numbers.
Adding to their difficulty was the fact that in previous times of struggle it was the seals that provided them enough food to sustain them through the difficult times. But each time the seal hunt provided enough food for the Norse to overcome the shortfall of production on their farms they increased their reliance on this one resource.
This made sense at the time. Most civilizations increase their reliance on resources that prove to be reliable, especially in times of stress, and decrease their reliance on resources that, for whatever reason, are unreliable. The Norse in Greenland did this, and we do this today.
By successfully adapting to the challenges of living in the harsh, highly variable climate of the arctic the Norse settlements became less resilient and fell into a rigidity trap which rendered them unable to adapt to a specific combination of challenges. Their increased dependence on the one resource that allowed them to survive previous difficulties sowed the seeds of their eventual collapse.
Generalists vs specialists
The trade-offs made by the Norse in Greenland are reminiscent of the specialist vs generalist trade-offs forced on animals and plants by evolutionary pressures.
A generalist animal is able to survive in a wide variety of environments by exploiting a wide variety of resources, conversely a specialist is only able to survive within a narrow range of conditions because it is only able to exploit a few very specific resources. As with all trade-offs there are advantages to both being a specialist or a generalist.
Generalists can be thought of as a jack of all trades but master of none. The perfect example of a generalist is the rat. It can survive in almost all terrestrial ecosystems, from ancient tropical jungles to the modern concrete jungles of human cities. Because it is a generalist it can easily adapt to changes in its environment and quickly begin to exploit new resources if the need or opportunity arises.
Specialists,on the other hand, are much less able to adapt to a changing environment and frequently find themselves unable to exploit new resources when the need arises. Pandas for example feed almost entirely on bamboo. If anything were to prevent the panda’s access to bamboo, they would not survive. In compensation for this trade-off specialists are better able to exploit very specific ecological niches that are out of reach to generalists.
Looking at the Norse civilization through this lens, it is clear that as the they moved northward to Greenland the harsh conditions they encountered pushed their civilization to become more specialized. This enabled them to exploit the limited resources available to them in Greenland. When faced with difficult times it was this specialization that helped them survive. But, over time, as they became ever more specialized at exploiting the migrating seals, they fell victim to a rigidity trap. They were now fully dependent on the seals for their survival. When climatic conditions made seal hunting impossible they faced a fate much like the one which threatens Panda populations when they lose access to the bamboo they require.
This specialization might have allowed the Norse to survive for a time in Greenland, but it left their civilization rigid and unable to adapt to changing conditions.
The question we need to ask ourselves is what aspects of our current civilization have become rigid and unable to adapt. There are undoubtedly many. Much like the Norse found it difficult to adapt, we are finding it difficult to change.
As the new emerging picture of what happened to the Norse of Greenland makes clear, successful short-term adaptation is no guarantee of long-term success. In fact successful adaptation can lead to less resilience and create dangerous vulnerabilities to later change.