Impacts on nature and for human societies

Coastal areas and systems are projected to be the most affected by sea level rise. Even if a rise of 3 mm/year doesn't seem much it is sufficient to have dramatic impacts on coastal areas and to noticeably diminish emerged land surface in low-lying regions, which are often characterized by rapid economic development and a high population density.

Sea level rise is expected to increase flooding from the sea in large deltas and low-lying areas, more particularly in Africa, Asia (Bangladesh) and Europe (the Netherlands). Coastal inundation, typhoons, storm-surges, floods, erosion are also expected to increase.

These natural phenomena induced by global warming will keep big pressure on coastal areas' infrastructures: housings, roads, administrative and business buildings. Different measures to protect the coast and the existing infrastructures will have to be implemented such as construction and reinforcement of seawalls, dykes and dunes.

Millions of people living in small islands and in or near coastal areas will be severely affected through loss of habitat and properties. Displacement of populations living in low lying areas represents a big challenge. This concerns especially developing countries which will have to bear a huge financial burden to relocate economic activities (agriculture, industry) and housings.

Another major consequence of sea level rise concerns water quality. Flooding by seawater will lead to salinization of groundwater that will have negative impacts on irrigation, aquaculture and fresh water availability. In some regions it will be necessary to invest in expensive desalinization techniques and to develop rainwater-harvesting systems.

It will accelerate the erosion of coastal lands and the destruction of coastal ecosystem and bio-diversity (coral bleaching, mangroves' submersion, extinction of plants and animal species). This negative impact on itself will also affect local economies based on the exploitation of natural milieu, like tourism.

The detrimental effects of sea level rise are projected to be global but some differences and inequalities are likely to appear between regions and countries.

The first kind of differentiation relates to the natural environment and its degree of vulnerability and ability to adapt to new conditions. The second relates to human and economic capabilities in areas like technology, research and development that could enable a society to innovate, mitigate and face the challenge successfully.

Developing countries, that have contributed a minor part to the human induced climate change, are paradoxically expected to be the most threatened by its negative effects and less financially and technologically capable to cope with them.