Global climate change and the vulnerability of the Nigerian coastal zone to accelerated sea level rise: Impacts and responds.
In the recent past, climatic changes and variations have occurred in Nigeria with resulting adverse socio-economic impact. From these experiences, it is inferred that the expected change in global climate will have far reaching disastrous consequences for Nigeria if appropriate anticipatory technical and policy Measure are not taken. More recent results from various models based on an eventual warming from a doubling of greenhouse gases of between 1.5 and 5oC by the end of the 21st century predict an acceleration of the eustatic rise in sea level from 1.2-1.5mm/yr. over the last hundred year s to 4 – 6mm/yr. although previous estimates were much higher [e.g.56–3.68m by the end of the 21 century] on the low lying Coastal zone of Nigeria, which is rich in natural resources and has amenities of high economic values, any global rise in sea level will be accentuated by subsidence phenomenon, both natural and man induced. This will, among other effects, result in the inundation and loss of productive wetlands, exacerbation of erosion and flooding problems, increased salinity intrusion into coastal rivers and groundwater aquifers, accelerated alteration of fragile ecosystems, greater influx of diverse pollutants e.t.c. Settlements will be uprooted, exploitation of natural resources including petroleum which accounts for greater than 90 percent of the country\s export and foreign exchange earnings as well as the rich fishery and staple crops, will be disrupted, communications infrastructure will be dislodged, businesses and industries [including the fledgling tourism] will be dislocated, and generally the level of human hardship and misery [e.g. due to pollution effects] will be high. Possible response measures to the expected impacts would vary according to the level of urbanization and economic investments in place and would necessarily be site specific. Shore stabilization, preferably employing low cost, low technology or soft engineering measures e.g. sand replenishment, is deemed imperative in heavily built up or industrialized areas with enormous capital values but outside of such areas, the best approach is to allow the sea to come in while applying technical and policy measures to mitigate the impacts. Strategies for increasing resilience to the impacts of higher sea Levels include relocation, improved land use [particularly to stop haphazard urbanizations and enforce set-back lines], efficient water management, adaptive agro – technology, provision of monitoring and early Warning system, public enlightenment campaigns, institution of disaster relief measures, etc. It seems self evident that the rational application of science and technology holds the key to the evolution of the most appropriate response measures. Beyond packaging effective anticipatory measures to tackle the expected impacts of the impending accelerated rise in sea level, additional problems associated with the management of Nigeria’s coastal zone call for the institutionalization of the enforceable coastal zone Management policy [and the concomitant authority] for a sustainable development of Nigeria’s coastal zone.
- Technical Report