Shrinking States

The Alliance of Small Island States (AOSIS) is an intergovernmental organisation of low lying island nations, formed with the purpose of protecting these island populations most vulnerable to the adverse effects of climate change. AOSIS has 44 member states and observers, most located within the Atlantic, Pacific and Indian oceans.

One such small island state is Kiribati, located in the Central Pacific Ocean it is composed of 32 atolls and one raised coral island.

Video explaining the threats facing Kiribati from climate change and rising sea levels and social issues from within the state.

Source: The Global Mail

Rising sea levels will have numerous environmental and sociological effects on The island of Kiribati and its inhabitants, all culminating to a complete loss of island life, destroying the community and traditions of the Kiribati people.

The most obvious of these effects is the complete loss of land as sea levels rise and erosion is enhanced by the increased frequency and strength of storm surges. Whilst most coastal areas can retreat when inundated by water, due to Kiribati's narrow size there is nowhere for people to go except to flee to other atolls already under strain from overpopulation or leave Kiribati altogether.

Another effect of the rising sea levels is the salinization of freshwater, a scarce resource on islands surrounded by saline oceans. Freshwater sources for Kiribati’s island communities are restricted to rainwater, shallow unconfined groundwater, imported water or desalinated ocean water. More and more of these sources are now becoming contaminated by the infiltration of saline seas and anthropogenic waste caused by the extremely high (and ever increasing) population densities of these small islands (some being equal to those in large cities such as London, UK and New York, USA, without the high rise buildings).


The effects felt if these small islands are submerged under water are not only sociological they are also ecological, with many islands hosting rare species and ecosystems. Kiribati has great marine biodiversity with 120 species of corals and 520 species of fish. These coastal environments can survive some sea level rise, however most, such as coral reefs, rely on their placement within the photic zone where microscopic algae can best provide photosynthesis for the corals. Therefore when submerged below this zone, beneath the area of influence from the sun, coral reef growth is inhibited.

So the question is, Why should these vulnerable small islands be the ones feeling the greatest effect caused by humanity's hunger for development, when they themselves contribute so little to anthropogenic greenhouse gas emissions?

Graph showing the Greenhouse Gas contributions of The United Kingdom, United States and Kiribati in 2010 (LUCF - Land Use Change/Forestry).
Kiribati's contributions is so small relative to The UK and USA that it cannot be seen in comparison.
Source: World Resources Center; CAIT2.0

In 2010 Kiribati produced 0.11 Mt of GHG (including the effects of land use change and forestry), USA on the other hand produced a massive 6,775.45 Mt. A staggering contrast that small island states are feeling the main consequences of.




References

Bernard Lagan. (2013). Kiribati: A Nation Going Under. Available: http://www.theglobalmail.org/feature/kiribati-a-nation-going-under/590/. Last accessed 30/10/2013.

World Resources Institute. (2013). Available: http://cait2.wri.org/wri/Country%20GHG%20Emissions?indicator=Total%20GHG%20Emissions%20Excluding%20LUCF&indicator=Total%20GHG%20Emissions%20Including%20LUCF&year=2010. Last accessed 30/10/2013.

Thomson Reuters. (2013). Tide of humanity, as well as rising seas, lap at Kiribati's future. Available: http://www.reuters.com/article/2013/06/13/us-kiribati-climate-idUSBRE95C04L20130613. Last accessed 30/10/2013.

Alliance of Small Island States. (2013). s. Available: http://aosis.org/. Last accessed 30/10/2013.

Taking it easy?

This blog post is a slight tangent to the main topic of sea level change but its an interesting argument about the validity of predictions being made regarding future sea level rise and its implications.

IPCC logo

An article in the journal Nature recently expressed concerns over the IPCC’s possible down playing of future predictions based on climate change. Whilst the overall article's subject was related to possible new sociological studies during the IPCC conferences, looking at the interactions between scientists during panel sessions where they discuss recent findings, model results and possible options for humanity.

There was however a small reference to recent sea level rise predictions and the fact that the IPCC chose to ignore the contributions of the Western Greenland ice sheet when publishing new projections for sea level rise. This was caused by an uncertainty into the validity of its modelling. The final assessment therefore projected a sea-level rise of up to 59 centimeters by 2100, even though many researchers currently predict a much larger rise.

Is the IPCC’s decision to downplay possible sea level rise due to uncertainty a good thing or is it simply a way of covering them from possible criticism if proved wrong?

Whilst it isn’t the time for scaremongering about unreasonable and untrue predictions this light and polite technique being used may be too soft on society. With the intention less on driving for support and publishing findings that have the majority consensus in the scientific community and more on covering the IPCC’s own back, in a tendency called ‘erring on the side of least drama (ESLD). Society may need a shock to get full attention on the problem at hand.

Here’s a link to the article:

http://www.nature.com/news/study-aims-to-put-ipcc-under-a-lens-1.13947

Another journal paper relevant to this subject can be found here:

http://www.sciencedirect.com/science/article/pii/S0959378012001215

It's titled ‘Climate change prediction: Erring on the side of least drama?’ and provides a discussion into whether the scientific community has begun releasing conservative predictions over the previously alarmist model projections in fear or social uproar and criticism if they are found wrong.

References

Jeff Tollefson. (2013). Study aims to put IPCC under a lens. Nature. 502 (7471), 281.

Brysse, Keynyn et.al. (2013). Climate change prediction: Erring on the side of least drama?. Global Environmental Change. 23 (1), p327-337.

200 Million People in Danger

I want to start by looking at a general overview of the effects sea level rise will have on human society. Whilst this may seem a little egocentric, I thought it best to begin with something everyone can feel empathetic towards, humanity.

Here is a great animation showing the areas on Earth likely to be flooded if sea water were to rise anywhere up to 6m. Whilst this amount of sea level rise is unlikely to occur in the near future it is not a completely unfathomable scenario for The Earth’s future.

https://www.cresis.ku.edu/sites/default/files/sea-level-rise/anim/world.mov



 

Figure based upon findings in the IPCC Special Report on Emissions Scenarios (SRES), showing number of people estimated to be flooded in coastal areas in 2080 as a result of sea level rise.

Source: UNEP Global Outlook for Ice and Snow Report 2007

 

The animation coupled with the graph above (showing populations likely to be affects by a sea level rise of up to 1m) really highlights the huge number of people that could and will be affected by future sea level rise, and the possible colossal consequences for human society, based on proximity to coastline and GDP/capita.

Some might argue that the human race has survived such rises in sea level in the past and whilst this is true, humanity has now evolved in such a way that past survival strategies used by such early humans are no longer applicable.
 

In the past when such changes in sea level made a region untenable its inhabitants would have been able to pack up and move on, rather than fighting the natural changes that were occurring. In present times due to the build-up of infrastructure in at risk areas and the large populations living at or below sea level, human society has lost some of their ability to adapt to these changes, therefore such a solution is no longer viable.
 

Society itself has also become more stubborn and unwilling to face the fact that while we are currently the dominant species involved in shaping this planet, it has not been and will not be that way forever. Changes in sea level have occurred throughout Earth’s history and will continue to occur for its foreseeable future, whether we are here to feel its effects or not.

Therefore we need to understand that it is possible we shouldn’t be changing the earth to mould around our needs, maybe we should be adapting based upon what the changes the earth and its systems are experiencing, especially since 9/10 times it is humanity that has induced such changes which are disrupting the natural order of things.
 

Even if greenhouse gas emissions were stabilised today sea level would continue to rise for centuries into the future due to the timescales involved with climate dynamics and the related processes and feedback mechanisms attached. Large amount of resources are therefore being placed in research into the development of new technologies capable of defending our coastlines and societies from rising sea levels. The question is though, how much longer can we hold off the inevitable destruction of our coastlines?

References

David Braaten et.al. (2006). Global Sea Level Rise. Available: https://www.cresis.ku.edu/sites/default/files/sea-level-rise/anim/world.mov. Last accessed 20/10/2013.
Nicholls, R.J. and Lowe, J.A. (2006) Climate stabilisation and impacts of sea-level rise. In Avoiding Dangerous Climate Change (eds. H.J. Schellnhuber, W. Cramer, N. Nakicenovic, T.M.L. Wigley, and G. Yohe). Cambridge University Press, Cambridge.

Nicholls, R.J. and Tol, R.S.J. (2006). Impacts and responses to sealevel rise: a global analysis of the SRES scenarios over the twenty-firstn century. Philos. Trans. R. Soc. Lond. A, 364, 1073-1095.

UNEP: Global outlook for Ice & Snow Estimates of people flooded in coastal areas in the 2080s as a result of sea level rise and for given socio-economic scenarios and protection responses. (June 2007). In UNEP/GRID-Arendal Maps and Graphics Library. Retrieved 20/10/2013. Available: http://maps.grida.no/go/graphic/estimates-of-people-flooded-in-coastal-
areas-in-the-2080s-as-a-result-of-sea-level-rise-and-for-given-socio-economic-scenarios-and-
protection-responses.

A Present Danger

Figure 1 - Graph showing past average global sea level values and projections for the future based upon scenarios run by The IPCC.
Source: The IPCC Fourth Assessment Report: Climate Change 2007.

“Global average sea level rose at an average rate of 1.8 ± 0.5 mm per year over 1961 to 2003 and at an average rate of about 3.1 ± 0.7 mm per year from 1993 to 2003.”^[1]

These were the findings presented in the Intergovernmental Panel on Climate Change (IPCC); Climate Change Synthesis Report (2007).

Theses finding show a marked increase in rate of sea level change from 1993 to 2003, this may simply be due to natural decadal variations in sea level, it could however also signify a more alarming problem, the effects recent anthropogenic warming is having on the rate of sea level change.

Such increases in sea level will have major effects on societies, both those in low lying coastal areas likely to be flooded, and those that will feel the secondary effects caused by increased pressure from displaced populations looking for refuge on their lands and resources. Not to mention the massive environmental impacts caused by the flooding and disruption (if not in most cases destruction) of unique ecosystems that form where land and water intersect.

This disruption/destruction will be the main theme discussed in the next few months within these blog posts.

References

[1] -Bindoff, N.L., J. Willebrand, V. Artale, A, Cazenave, J. Gregory, S. Gulev, K. Hanawa, C. Le Quéré, S. Levitus, Y. Nojiri, C.K. Shum, L.D. Talley and A. Unnikrishnan, 2007: Observations: Oceanic Climate Change and Sea Level. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

We've gotta start somewhere

Figure 1 - A map of Europe showing an imagined alarmist coastline plan if all The Earth's ice were to melt, which at current rates it is estimated could occur within 5000 years.
Map: National Geographic

In this blog I plan to look at the effects eustatic sea level fluctuations have had on planet earth and its inhabitants, from the naturally induced fluctuations of the Late Quarternary to the more alarming increase in sea level since the mid 1800’s, (The recent Anthropocene - if you believe we have entered a new epoch of human influence) and even to the future, looking at possible outcomes of the predicted rising.

First i'll set the scene by explaining some of the main factors that cause such fluctuations in global absolute sea level over the earths history. Eustatic sea level is mainly influenced by changes in the volume of water found in the oceans. It is however also affected by morphological changes to the earth’s surface resulting from tectonics, subsidence, glacial isostatic rebound and sedimentation, which alter the volume of the ocean basins which contain the water.

There are two major factors which cause the volume of ocean water to change on a global scale, the amount of water locked up in oceans vs. other reservoirs, and the temperature of the ocean at the time.

The thermal expansion coefficient of H₂O is such that when placed at higher temperatures the volume of a body of water expands, therefore when earth experiences an increase in surface temperature the oceans will be heated and the water will expand accordingly, greater volume of water in the oceans means a higher eustatic sea level (other factors remaining the same).

An increase in surface temperature also leads to the melting of glaciers and ice sheets, causing a greater percentage of the earth’s water to be held in the oceans relative to other reservoirs, increasing eustatic sea level. Anthropogenic factors such as land hydrology can also affect the relative proportion of water storage in oceans against land reservoirs, however this occurs on a more regional scale and therefore its effects are generally felt over shorter timescales.

Although humans may not be directly pumping the vast majority of water into the oceans that is causing sea levels to rise so drastically, we are responsible for the intense period of warming The Earth is currently experiencing (although that is another debate for another blog). It is this warming that is causing modern eustatic sea level rise that is threatening so many of earth's present day ecosystems and societies.

I’ll end this post with a link to the 2007 IPCC report on climate change, specifically the chapter titled; Observations: Oceanic Climate Change and Sea Level., which goes into the subject of what causes sea level rise in more depth and is a good read if you are interested in the subject of sea level rise or oceans in general.

References

Bindoff, N.L., J. Willebrand, V. Artale, A, Cazenave, J. Gregory, S. Gulev, K. Hanawa, C. Le Quéré, S. Levitus, Y. Nojiri, C.K. Shum, L.D. Talley and A. Unnikrishnan, 2007: Observations: Oceanic Climate Change and Sea Level. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

Pirazzoli, P (1996). Sea-level changes - The Last 20000 Years. Chichester: John Wiley & Sons. p5-15.