Tuesday 12 January 2016

Goodbye Readers!

Finally we have reached the end of this blog! At the start of this blogging journey I was certain that environmental factors played a major role in many of the ancient societal collapses studied in this blog. However, I gathered pretty early on that there was such uncertainty about what happened in the past that it was much more probable that a whole multitude of effects (including societal and cultural factors) was the reason why some past to societies declined.

Yet I still feel looking at the past is great for us as we move forward as, in the problems faced in nearly all of the examples of collapse in ancient cities are the problems we still face today- deforestation, reduced water security, aridification, invasive species and climate change. Thus by looking at how these factors affected societies may aid us in predicting what mean for populations today. However, in the end  I remain hopeful and fairly certain that a societal collapse could not happen in the future as I don't believe that in this globalised world we will let a society collapse and I remain optimistic in thinking that somewhere solutions are being thought of and put in place to mitigate the impacts of the problems we face.

In the end I hope you all enjoyed reading about past societies and saw how they can relate to our future. I also hope this blog has inspired you to find your own ancient societal collapse casestudies as there are still many out there waiting to be analysed but until I pick up the blogging quill again, I bid you adieu!

A new lost city? A new casestudy for collapse?

With the end of this blog approaching it was quite nice to come across this article in the National Geographic.

There are finally plans to excavate an ancient lost city in Honduras, Central America. The site is located Eastern Hounduras in the Mosquitia region where it is believed there lies several other lost cities. 


The Mosquitia region, Honduras (Source:National Geographic)

The ancient site already has numerous stone artefacts as well as pyramids and plazas but nothing is known about the society that lived there and its culture. Will this lost city provide us with a new case-study for collapse? Only time will tell...


One of the artefacts found in the ruin - a part jaguar spirit and part human sculpture which is part of a ceremonial chair (Source:National Geographic)


Monday 11 January 2016

Environmental Determinism vs Possiblism

So this topic was inevitable when talking about whether environmental changes could cause societies to collapse.

For those of you who don't know environmental determinism is the concept that ' the physical environment can affect and limit the development of societies'. The theory began Ancient Greece by Hippocrates who stated 'in well watered regions the people will be lazy and incoherent whilst people from rougher environments will be hard, lean and articulate'. This idea became very popular in the USA where it was advocated by Friedrich Ratzel and Ellen Semple. However, the theory is highly controversial and quickly lost pace as the view that people and their success was determined just by their environment is seen as simplistic and practically ignores innovation and downplays human ingenuity

Another theory that tries to overcome the limitations of environmental determinism is possibilism. Ancient Grecian Strabo suggested that 'men flourish in any latitude' and that different environmental conditions instead offer pathways with choices for development. 


The difference between environmental determinism and possibilism (Source:Buzzle)

Looking at the past and trying to understand why some societies decline through this blog whilst the environment does affect how societies operates and poses challenges to them they do not control what happens to a society. How societies respond to challenges is key to their development and where some past societies have prospered and others failed is most likely due to a combination of issues that were present in the society. Moreover, in the casestudies explored in this blog it seems that societies did have some resilience to changes in their environment and that if environmental conditions did place extreme pressures on societies (e.g. food, water, resource scarcity) it was these knock-on effects that caused societies to decline. Looking forward it seems likely that whilst climate change and negative environmental impacts will affect societies, the way we respond to such challenges (e.g. COP21) -alongside continual improvements in technology, research and knowledge- will be the main determinant of how societies develop.

Overall, the environment and societies have a two-way relationship and any societal collapses are often the cause of a multitude of effects which environmental change may be a factor.



Disclaimer: This blog and blogger in no way advocates environmental determinism! (she knows too well that procrastination has nothing to do with where you are - sorry Hippocrates).

Thursday 7 January 2016

Islands - Here today gone tomorrow!

Looking at the collapse that occurred in Rapa Nui it is quite obvious how fragile island systems are. This is true even today when around 10% of the global population (around 600 million people) live on islands and as a quarter of the world nations comprises of islands. In fact the area covered by island and their exclusive zones cover a sixth of the world's surface. 

Islands are important not just for the people who live on them and economic value but also for the biological value as many islands have important ecosystems and are home to a high number of endemic species. They may also be politically important as sites of contention between nations.

However islands are under threat! Anthropogenic warming and the predicted rise in sea level puts many cities below sea level and islands at risk. This clip from the BBC illustrates the threat to island state Vanuatu from climate change and this is true for many islands states such as Kiribati, the Maldives and the Republic of Palau (e.g. a rise of 1m will mean more than 85% of Male will be underwater). 

Other then the danger of going under the sea, climate change is expected to cause:
- saline intrusion
- erosion of the coastline
- more intense tropical storms (further eroding beaches)
- damage to coral reefs (from higher temperatures and sea levels)
- economic losses (no tourism, less farmland causing a negative multiplier effect)
- forced migration to higher ground or even mass relocation
- emigration and possible societal issues that arise from that
Among many other problems.

What will climate change do to developing island nations? (Source: Grida)
Whilst the need for action to help island nations is obvious in these articles David Cameron and Ban Ki-Moon urge island states to 'amplify their voices' and to really push for change! This statement actually made me flashback to our COP21 seminars where despite the pleas and protest of the 'other developing nations and island states' their voices were often drowned out by the more developed nations in a battle with each other about the climate fund and accountability. Now of course this was just a stimulation and (hopefully) in reality the islands states can voice their opinion but just much power do they have to influence climate deals?
Something that I found quite ironic in these articles was that the statements asked island nations to really take part in the COP21 deals as if they haven't before when island nations have been trying address their plight in climate discussions for years! I remember watching the 'Island President' back in 2011 (a good documentary - minus the slight propaganda) which followed the President of the Maldives as he aimed to ask for co-operation in regards to climate change and its impacts on islands to the Doha climate talks 4yrs ago. This goes to show that island states have been aware of their situation for years but have been unable to get nations to mitigate the effects that climate change will have on them.

Moreover, many of these states are developing nation and simply cannot afford the losses and damage costs that they will incur as a result of global greenhouse gas emissions which they hardly contribute to. Many of these nations are also part of the 'Small Islands Developing States' organisation with their own development goals that recognises island nations' limits but aims to help them overcome these obstacles and develop sustainably. In fact some developing islands have made significant strides in sustainable practices compared to developed nations. For example, Barbados is using solar water heating as an alternative energy source and Bonaire in the Caribbean is the first island to go 100% sustainable.
Nonetheless, to ensure the future of island societies it is imperative to address the challenges they face from climate, to offer support from the negative impacts of climate change, to offer financial support for less developed towns (which the climate fund could help with) and plans need to be considered and put in place should the worst happen and societies need to completely relocate.

 But will island nations really disappear? This article from the National Geographic suggests they may not. Studies show that reef islands are highly dynamic and can react to changes in sea level rapidly. This means that as sediments move so can they and this actually lead to a increase in size. The study shows that 80% of 600 reef islands grew or remained the same meaning sea-level rises may not devastate the islands. Moreover, a faster sea level increase actually makes the reef more dynamic and thus the reef islands may can survive in the future too. Other ways that islands may in fact be protected is from organisms that change dead corals into sediments and so whilst coral bleaching destroy the organisms, it may help increase the sediment budget in an island which can help against rising sea levels. However, in regions were permanent structures have been put in place (e.g. seawalls, roads) the dynamic reefs cannot move these features and so are still threatened by sea-level rise.

Overall, islands are in danger from climate change and this puts societies at risk of a collapse. However, the climate negotiations made in Paris can help reduce the risk island states face and with this international co-operation hopefully these islands states are safe from a demise like that which befell on Rapa Nui.

Islanders protesting against polluters deciding the fate of their home (Source: Popular Resistance)


Sunday 3 January 2016

Casefile: Rats! All the trees are gone...

Greetings readers! Now while the title may confuse you don't worry this post is all about the collapse that occurred in Easter Island - one you are all familiar with thanks to the last seminar and so here's just a brief overview of what may have happened.

Background:
Rapa Nui (as its is also known) is located in between the coast of Chile and the Polynesian Pitcairn Islands and is a small island covering an area of 171km2 (Fig. 1). Polynesians are thought to have settled in Fiji and Hawaiian islands before a community developed on Rapa Nui at a late date of around 1200 A.D.. Evidence for this data came from various sources including: the radiocarbon dates of seeds eaten by Rattus exulans (a Poynesian rat that is associated with humans), by a change in vegetation after this period and by study the only dune on the island - Anakena which provided a chronological record of the island. Anakena is thought to have been the first site of occupation by the early settlers as there was no evidence of a settlement before 1200 A.D. after which cultural objects indicative of humans appeared. We also know that the occupants the land and changed both the near-shore and terrestrial surfaces of their island through farming and the erection of statues and it is thought they had reached a population of at least 10,000 before the decline. At 1650 A.D. the society collapsed and wars ensued as populations dwindled and the society experienced cultural shifts. Rapa Nui was then discovered by Dutch sailors on Easter Sunday and renamed the Easter Islands by Jacob Roggeveen who saw the island in 1722. And when visited by James Cook in 1744 the island only had a population of 1000 and had no trees. 

A number of theories have been put forth as the reason for the drastic decline in population and degradation that occurred in Rapa Nui but much of this is still heavily debated making this examples an interesting but certainly one of the most controversial casestudy on collapse out there.

Fig. 1 - Map of Rapa Nui (Source:Welt-Atlas)

The Theories:

Rats! - Terry Hunt (2007) suggested that Rattus exulans were to blame as they caused widespread deforestation on the fragile island ecosystem. Islands are unique in that there isolation creates endemic species with few large predators and simple ecosystem thus the introduction of the Polynesian rat meant the species thrived as it faced very few limiting factors (no predators, no seasons and lots of food). Since the Pleistocene Jubaea palms have been present on Rapa Nui and this is indicative that the deforestation experienced on the island could not be explained by changes to the climate. Thus the rats, thriving on the abundance of food (seabirds and Jubaea nuts) and lack of predator, were able to quickly reach a high population (45 rats per acre meaning a population of at least 1.9 million probably more!) which could cause significant degradation. 
Evidence for the negative impact of rats comes from palynology which studies pollen and seeds which could be used to reconstruct the islands vegetation and which had evidence of gnawing by rats. Faunal remains were also studied and showed the species composition and abundance of rats on the islands.

However, Meith and Bork (2010) argue that rats couldn't have caused the devastation on Rapa Nui as less than 10% of nut had evidence of teeth mark, the age and presence of stumps suggested humans had cut them, carbon remains suggest fires occurred, there was still evidence of young palm trees and trees do have some resistance to predation. Nonetheless, Hunt states that the rats along with logging and the use of fire by humans would have caused the devastating impact seen the land. He also states the role of rats have been understated as they can cause major damage as seen in 'Ewa Plain of O'ahu'  where rodents obliterated a palm forest. As opposed to humans simply felling the last trees he offers the opinion that rat may have eaten the seed and this illustrates the negative impact an alien species can have on fragile ecosystems.



'Rat Attack!' (Source:Radiolab)

Europeans! - We all know of the damage that colonists do to a country and it has been proposed the same happened to Rapa Nui. The European colonisers brought about the destruction of the island through introducing new diseases, reducing the population by using them in the slave-trade or genocide and by taking resources from the island further depleting the islands natural stores. However whilst the data does show a sharp collapse in population after Europeans first arrive, the environmental destruction and initial population decline cannot be solely attributed to them.


Ecological Destruction (or 'ecocide' for the dramatic)! - One of the most prevalent theories but also controversial as it depicts the islanders as irresponsible. This theory is known as 'ecocide' as it is believed humans caused widespread devastation to their local environment (tell us something new right?). The trees were likely felled to be used for building materials, boats and for the construction of the moai statues. The theory goes that the Polynesians cut down trees faster than they were growing back this along with cut and burn practices left the vegetation with little chance of recovery. This evidence was found among trees stumps which were clearly felled, the presence of the iconic Easter Island statues, pollen data which showed the prevalent presence of palm trees until the arrival of humans and charcoal and carbon found in sediment records. J. Diamond even suggests that the population resulted to cannibalism as overpopulation and a degraded environment had weakened the ecosystem the society relied on.


Drought! - Lake sediment records found that the Rano Raraku lake dried out once after 4410 B.P. before returning in 1180-1290 A.D. After this drought the Polynesians started felling trees and burning the soil leading to serious erosion. The islands climate is heavily controlled and affected by ENSO, shifting storm tracks and sub-tropical high pressure system. Whilst there is not much evidence from the island itself, proxy data from Patagonia on moisture levels (tree-rings and lake sediment records) illustrate a shifting pattern of cool-moist to dry climates between 900 to 1270 AD.. Therefore, it is expected that the island did experience a droughts at the same time as in Chile. Thus the climate may have caused the collapse as moisture levels changed and affected aridity.


'They found neither trees nor chocolates' (Source:New Yorker/TheAwl)
Whilst we may never know what caused the collapse in Rapa Nui and blaming the islanders due to their unsustainable practices seems like an environmental determinism point of view, this casestudy is interesting in the addressing the problems societies face even today. Many island nations are already starting to feel the pressure of climate change and rising sea levels but this example also resonates with societies who continue to over-exploit resources quicker than their replacement rate. What's more it introduces the possibility that invasive species or even degradation of fragile habitats can have devastating effects on humanity...

Wednesday 30 December 2015

More on ENSO

After discussing ENSO as the primary cause for the Aboriginal decline in Kimberly in an earlier blogpost I kept seeing new articles popping up about the devastating impacts this 2015 ENSO was having across the world.

What I did not realise however was that the ENSO was having such a massive affect on so many countries including the UK! I came upon this Buzzfeed article describing how El Nino is the cause of some of this horrid weather we've been having. Okay so I know it's hard to distinguish between the different rubbish weather we've been getting but this winter has been one of the wettest and this year has also been one of the warmest. This is the result of both ENSO and climate change. An El Nino event causing warming of the equatorial waters of the Pacific which in turn warms the atmosphere driving global weather. The El Nino has led to warm and wet conditions in the North which has resulted in the severe floods we've seen in Britain this winter, and its predicted to do the in 2016. 

The floods in Leeds (Source:The Guardian)
Moreover with rising temperatures due to climate change and future ENSO events the frequency and intensity of storms are expected to increase with unprecedented impacts on societies. This will not only affect the UK but nations around the globe too and whilst there are already worries on the UK's flood defences just imagine the impacts in densely populated developing countries!

ENSO is also predicted to cause environmental damage as this articles suggest record temperatures will cause serious fires in the Amazon which may devastate the local ecology and lead to more carbon being released into the atmosphere. 

Thus like the the situation in Kimberley, climate change coupled with a strong and slightly unpredictable ENSO may have serious consequences on societies across the globe if preventative methods are not taken. Nevertheless, continual monitoring and possible warning systems may help nations be better prepared to deal with future climatic stress.






Friday 25 December 2015

Merry Christmas!!

Just a little present to spread the Christmas cheer! Click here for some special climate change carols we'll all be singing in a few year (yay?!)....

source: Gareth's World