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  • Navoneela Chakraborty

Sea-level Rise (SLR) - Part I

Humanity’s existential crisis structurally linked with Industrial Civilization (IC) & Ecological Overshoot

‘Life on this earth first emerged from the sea. As the polar ice melts and sea level rises, we humans find ourselves facing the prospect that once again we may quite literally become ocean.’ -  John Luther Adams


The anthropogenic global warming or in other words Industrial Civilization powered by fossil fuels has triggered the SLR by the thermal expansion of the ocean as well as the melting of the terrestrial ice. SLR can pave the way for an extreme event (a slow-moving catastrophe). Data suggests that the 20th century witnessed a faster rate of SLR than the 18th and 19th centuries. And in the 21st century, it has risen by more than 2 times- from 0.06 inches per year in the 20th century to 0.14 inches per year between 2006 and 2015. If we consider the year 1880, since then the sea level has witnessed a total rise of 23 cm. These data imply that the rate of SLR is accelerating. As per a recent 2022 research, it is estimated that the rise is going to be by a foot by 2050.





Satellite data showing the SLR in recent years







SLR- a consequence of the smooth operation of the Industrial Civilization (IC)

The modern IC is a Megamachine (Fabian Scheidler, 2020) that is overwhelmingly powered by fossil fuel energy. Our dependence on fossil fuels has increased since the dawn of the Industrial Revolution and even before we realize, it has started contributing to climate change. The excessive use of fossil fuels has led to greenhouse gas emissions (GHG) beyond levels that our planet could sustain. Moreover, deforestation has destroyed vegetation which used to be the main sink of GHG.

Thus, the gases are trapped here and have given rise to the phenomenon of global warming. The resultant heat imbalance has led to climate change, thereby triggering SLR that could possibly lead to societal collapse and mass extinction in the near future.


The increase in the use of fossil fuels over the years


The global SLR is a threat to a huge population, infrastructures, economy

The global SLR is a threat to a huge population, infrastructures, economy, and ecosystems of the coastal areas. Even a small rise can lead to adverse effects, an account of which is given in the following points:

I. The intrusion of salt in groundwater, surface water, and fertile agricultural soil is one such instance of how SLR can contribute to the overshoot. It occurs as a result of high storm surges, the occurrence of high tides, and the infiltration of sea water in freshwater aquifers. It has become a major issue in areas like the northeast USA where the sea is rising at the rate of approximately 3mm per year. Consequently, large storm surges and high tides are becoming more frequent, thus increasing the rate of saltwater intrusion more than in the past decades.


II. Another phenomenon accelerated by SLR is the occurrence of extensive coastal erosion by rising waves. The increase in the heights of waves, combined with a lack of sediment supply, has triggered lateral erosion to the maximum. This, in turn, is leading to the loss of coastal property like buildings, infrastructural facilities like roads, etc. A paper titled ‘Effects of Sea-level rise on coastal cities and residential areas’ by Roland P. Paskoff quotes that ‘Beach erosion is already prevalent on a global scale since more than 70% of the world’s sandy shorelines are presently retreating, with only 10% are prograding and the remaining 20% stable’.


Coastal erosion — a consequence of SLR


III. Coastal wetlands, which act as a buffer between seas and the inland population, are also facing extreme challenges due to the SLR. Due to increased flooding and salinity, it is expected that the area under coastal wetlands is on a decrease which, in turn, is going to increase flooding and inundation risks of the inland communities. For instance, a 2008 paper titled ‘Mangrove forests: Resilience, protection from tsunamis and responses to global climate change’ by Alongi estimated a maximum worldwide loss of mangrove forests between 10 and 15% due to SLR.


IV. SLR can also accelerate storm surges and flooding during tropical cyclones. In other words, a higher sea level can contribute to the formation of more dangerous tropical cyclones. Research suggests that densely populated regions that have witnessed a rate of sea level rise equal to or more than the global average are affected by coastal flooding caused by tropical cyclones. In Fiji, storms and rising sea levels have combinedly caused devastating floods that snatched away about 11 lives and made a population of 12,000 temporarily homeless in January 2009.


V. Mass migrations are going to be another serious impact of SLR that can pave the way to overshoot. A 2011 article titled “Sea-level rise and its possible impacts given a ‘beyond 4°C world’ in the twenty-first century” estimated that about 187 million people would be compelled to leave their houses and migrate to new areas due to SLR by 2100. More recent works of almost a decade later suggest the figure to be 630 million.


All these pose a major challenge to the terrestrial ecosystems in the coastal areas as they are reducing the carrying capacity (bio-capacity) of our planet by destroying its resources. Our planet’s carrying capacity revolves around the nine planetary boundaries within which human communities can survive in the present and future. Problems arise in the Earth’s carrying capacity when these boundaries exceed their desired levels. As a result of SLR, some of the planetary boundaries including freshwater use, biodiversity loss, and land use change have changed and have crossed the limits of their safe operating spaces. These, in turn, are giving rise to overshoot (https://www.stockholmresilience.org/research/planetary-boundaries.html).


Is SLR a fait accompli or a Predicament? Or Both?

We at GCR see it as both. It can be argued that it is possible to limit SLR by halting global average surface temperature rise to 3, 4, or 5 degrees by the end of this century. But such a choice calls for giving up on fossil fuels, or in other words halting the operation of the megamachine called Industrial Civilization especially when humanity & human systems are adapted only to the usage of fossil fuels for the sustenance its ‘Way of life’. It is falsely argued that a transition towards green energy will solve the predicament but little do we realize that even the setting up of renewable or non-polluting energy sources involves the use of fossil fuels or emissions of greenhouse gases. In short, we have reached a stage when it is neither possible to eliminate nor mitigate the causal factors SLR. This is what makes SLR a fait accompli, because even if we stop all greenhouse emissions today (very unlikely) we are already condemned to several feet of SLR for centuries to come. It is a predicament (a moral choice) only to the extent that, in the interest of the welfare of future generations, humanity can mitigate the extent of future SLR by making hard collective choices today namely voluntarily (or involuntarily) forsaking fossil fuels, thereby bringing a closure to the short burst of exuberance called ‘Industrial Civilization’.


 





Navoneela Chakraborty

RESEARCH ASSISTANT

B.A. in Geography from Kamala Nehru College, University of Delhi



(More about Global response options and transition plans will be discussed in Part-II of this essay)


References:

https://www.oecd.org/env/cc/2483213.pdf


https://www.nationalgeographic.com/environment/article/sea-level-rise-1


https://www.climate.gov/news-features/understanding-climate/climate-change-global-sea-level#:~:text=In%202020%2C%20global%20sea%20level,per%20year%20from%202006%E2%80%932015


https://envirobites.org/2018/12/10/sea-level-rise-and-coastal-wetlands-predicting-the-future/


https://www.researchgate.net/publication/259200773_Coastal_flooding_by_tropical_cyclones_and_sea-level_rise#:~:text=Abstract%20and%20Figures,of%20accelerated%20sea%2Dlevel%20rise.


https://www.sciencedirect.com/science/article/pii/S0272771407003915


https://www.climatehubs.usda.gov/index.php/hubs/northeast/topic/saltwater-intrusion-growing-threat-coastal-agriculture


https://sealevel.nasa.gov/faq/14/how-much-do-human-activities-contribute-to-sea-level-rise/

https://www.nationalacademies.org/based-on-science/human-driven-climate-change-is-causing-sea-levels-to-rise


https://www.iucn.org/resources/issues-briefs/ocean-warming


https://www.eolss.net/sample-chapters/C12/E1-04-04-03.pdf


https://royalsocietypublishing.org/doi/10.1098/rsta.2010.0291


https://ourworld.unu.edu/en/sea-level-rise-is-inevitable-but-we-can-still-prevent-catastrophe-for-coastal-regions

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