Erosions And Floods – New Zealand’s Battle Against Rising Sea-Levels


Various parts of New Zealand’s capital city and its surrounding suburbs face the risk of devastating floods, as indicated by the Sea Level Mapping Tool. This interactive tool, recently designed by Greater Wellington Regional Council (GWRC), reflects the disastrous impacts of sea-level rise, accelerated by global climate change. The Wellington region is particularly vulnerable to even a meagre rise in sea level because of its small tidal range. Intensified and increased occurrences of storm surges are likely to increase the already rising sea levels by alarming proportions.


Sea level rise adversely affects the coastal communities, biodiversity, ecosystems and infrastructure. The New Zealand Parliamentary Commissioner for the Environment, 2015 observed that communities (including the marae) and infrastructure (including urupā) are directly affected by rising sea levels through the increased risks of flooding and soil erosion. Rising sea levels will adversely affect New Zealand’s flora and fauna, taonga species, and habitats around the coastline. The damage caused by the erosion and flooding of natural habitats by the sea cannot be replenished due to the unsuitable land on their landward edge. Salinization of freshwater bodies can also potentially alter the osmotic composition of freshwater, resulting in the death of freshwater fishes. Estuaries, coastal wetlands, and coastal margins risk being permanently lost due to coastal squeeze.


Once statistically rare, natural disasters could disproportionately increase. For instance, over the last century, rising sea levels had nearly doubled the number of days when tides reached the 1900 ‘king tide’ level. In New Zealand, this level symbolizes a red-alert, sending a warning against an escalating potential for coastal inundation. In the low-lying areas, draining naturally by gravitational pull, the drainage of stormwater systems will become increasingly complex with the rise in flooding, wave overtopping, and groundwater levels. The present 1-in-a-100-year flooding will become five times more likely with the twelve centimetres of sea-level rise. By 2050, more than 10,000 homes around the coast will bear the brunt of catastrophic climate change as the dangers of inundation will result in insurance companies pulling out of coastal properties.


New Zealand is exposed mainly to facing the consequences of unrestricted emissions of greenhouse gases, predominantly anthropogenic in origin, incessantly being released in the other hemisphere of the world. In a recent study, leading scientists from Victoria University of Wellington’s Antarctic Research Centre called for an immediate reduction of greenhouse emissions. According to their findings, sea-level rise from melting glaciers and degenerating ice sheets will be halved in the 21st century if the Paris Agreement’s target limiting global warming to 1.5°C is met. Going by their predictions, if global warming is limited to 1.5°C, rather than the present three degrees Celcius (which the global governmental emissions pledges to commit to), then the resulting sea-level rise from melting ice shelves could be significantly reduced. By 2100, this cut could amount to thirteen centimetres from twenty-five centimetres, mainly reducing the costs and impacts of coastal flooding worldwide, particularly in New Zealand.


Acknowledging the need for a comprehensive response to sea-level rise, the government endeavours to connect an informed and engaged community with appropriate regional planning and a long-term decision-making system. However, it needs to be understood that as a global phenomenon, the responsibility to combat the precarious consequences of climate change should not be on any individual government. Half of the origins of global warming, whose impacts threaten lives in New Zealand, are to be found on the other side of the planet. Therefore, it is imperative that the global community, supported by international organizations, un-hijacked by the principal emitters of greenhouse gases, pledge to curb the accentuating global warming.


The human mastery and control over the environment have reflected the exploitation perpetrated by the former and the degradation of the latter. At its altar is sacrificed nature’s assets. Animals have lost their habitat, trees have been razed to the ground, and migratory birds no longer find their travel destinations, as seasonal variations leave them utterly confused. The need to recognize their rights to the environment cannot be overlooked. Even in mythical texts, the rejuvenation of life and the earth are symbolized by the return of a bird an olive branch in its mouth. Notwithstanding the agreement over the story’s dubious scientific credentials, it may still be worthwhile to note the importance of flora and fauna in nature’s sustenance. If they perish, the human world will soon discover its vulnerability behind a façade of technological prowess.

Sucharita Sen


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