Sand, sea and sunshine — the charms of a coastal area — make people dream of living by the sea. Nothing is comparable to the beauty of a settlement by the sea and that is perhaps the reason why most major cities are located near the coasts. Being home to one-fourth of the world’s population, coastal areas are not only tourist destinations but the hub of economic activities as well.

Over a century back, due to nonexistence of environmental pressures, establishment of settlements near the coasts seemed justified.

However, though the growing population over the years witnessed some environmental decline, the natural assimilative capacity of the coastal ecosystems was able to withstand the low-level environmental degradation.

Is it wise to develop settlements in coastal areas when faced with threats due to a rise in sea level?

It was when large-scale urbanisation and industrialisation of coastal areas began that a significant environmental degradation took place.

Responsible cities were able to safeguard coastal areas through rational settlement policies and establishment of efficient infrastructure, principally wastewater treatment systems.

Rise in sea level, alone or in combination with land subsidence, has the potential to wipe out coastal settlements, seriously questioning the rationale for establishing new settlements in coastal areas.

Here a major question arises: to what extent sea level will rise in future? There is some debate on this. The 2007 Intergovernmental Panel on Climate Change (IPCC) projects sea level rise to be in the range of 18 to 59cm by 2100. Many scientists and coastal experts find the IPCC projections flawed, as the projections did not include melting of the Greenland and West Antarctic ice sheets. If they are taken into account, the global sea levels could well rise 1m to 1.8m.

However, the IPCC in its report released in September 2013, revised the estimate of rise in sea level, and now it is estimated to be 28cm to 98cm by 2100. This is nearly 50 per cent higher than the 2007 estimates.

Coastal development now faces major hazards that seriously threaten their existence. Climate change, natural hazards, extreme weather patterns, flooding, erosion, land subsidence and, most of all, rise in sea level will exert significant pressure on the coastal communities.

Rob Young of Western Carolina University and Orrin Pilkey of the Duke University, and authors of The Rising Sea, estimate a rise of 2.1metres in sea level by 2100. Coastal developments, in no way, would be able to withstand a 2.1m rise in sea level. Scientists say that the coastal areas should be prepared for 2.1m rise. The authors are of the opinion that the continued development of many low-lying coastal areas is foolhardy and irresponsible. They recommend immediate prohibition on the construction of high-rise buildings and major infrastructure in areas vulnerable to future sea level rise.

A NOAA (US National Oceanic and Atmospheric Administration) report of December 2012 says with very high confidence (greater than nine in 10 chances) that global mean sea level will rise at least 0.2m and no more than 2.0m by 2100.

In addition to almost permanent flooding in the coastal areas, the high sea level rise will salinise water supplies; impair food quality; affect livelihoods; increase mosquito-borne infections, diarrhoeal diseases, and skin and eye infections. Sea level rise will create millions of environmental refugees. It will be more expensive for people to insure their homes in coastal areas, due to high risks involved. Insurance is a mechanism through which people protect their assets against disasters. On the other hand, the coastal developments create impacts that reduce the ability of natural systems to react to changing climate.

Making coastal areas resilient to the effects of sea level rise would involve huge investments. Stephane Hallegatte of the World Bank, Robert J. Nicholls of University of Southampton and colleagues, assessed the risks of future flood losses in 136 large coastal cities (Aug 2013), and found that the cost to the coastal cities from flooding is expected to rise to $1 trillion in 2050. A recent study estimated the costs of adapting to just a one-metre sea level rise in the US would amount to $156 billion (3pc of GNP). Most countries don’t have this kind of money to spend.

Even the huge investments made for adaptation and protection would not be able to withstand the onslaught of a 2.1m rise in sea level. Besides, it makes no sense to spend billions on the infrastructure to protect the recent investments in developments in the coastal areas. It is a common saying, and it is true, that most squirrels plan for the future better than humans do.

Published in Dawn, Sunday Magazine, September 14th, 2014