Sea level rise and coastal zones

According to the article of Robert J. Nicholls and Anny Cazenave (2010), the sea level rise is due to the dilatation of the ocean (30%), the loss of the glacier (60%) and to the human activities as the ground water mining for example (10%).

More important, this article enlighten us on a very critical point. The sea level rise is not uniform over the earth. The rise of the West Pacific Ocean is three times more important than on the North American Coast. Thus, all the coasts will not pay equally the consequences of the SLR. Thus the SLR will be up to 30cm to 180cm in 2100.

The impacts on the coastal zone are the submergence and flooding of the lowest zone. Also, some intrusion of salt water in the surface waters and groundwater, but also the pressure on many coastal ecosystems as the Mangroves and the corals. These impacts will be proportioned to the relative SLR because the coast are upwelling in some regions and subsiding in some other, especially in the important metropoles multiplying the cost of societies.

 These impact will have major socio-economic consequences. Indeed the coastal ecosystems and landscapes are often a source of income for the touristic economy. The effects on tourism could be serious for many countries.

Below sea level lands in Netherlands

However, the authors are very confident in the human capacity of adaption and to their point of view, major population retreat are going to be inevitable. They use the example of the Netherlands who are already reinforcing their seawall. The Netherlands which have already many lands below the sea level have the means to act against the risks. Not all the countries have these means making them much more exposed than the Netherlands. 

Bibliography:

Nicholls, R.J. & Cazenave, A. 2010. Sea Level Rise and its impacts on coastal zones. Science. Vol. 328. No.5985. p1517-1520.  http://www.sciencemag.org.libproxy.ucl.ac.uk/content/328/5985/1517.full

Save the ecumene

If humans were selfish enough to not care about the protection of many mammals and their ecosystems, and silly enough to not understand that the extinction of some ecosystems could lead to their own extinction, I still hope they understand that desertification and rising oceans affect directly the human activities by reducing their “territory”: The ecumene. Indeed, the Sahara and Atacama Deserts are not the most populated place and the inhabitant of the Atlántida could attest that cities are not fully waterproof yet.

The city of Malé

To those who think a little bit more than the uneducated consumers, they will understand that to shrink the ecumene increases the anthropic pressure on the other ecosystems. Indeed, the ecumene is not only the exclusive space of humans, but a space humanity share with many ecosystems. By shriking the ecumene and given the rapid population growth, the human densities are going to jump and the pressures on the ecosystems which share the ecumene with humanity are going to explode.

According to the IPCC, the rise of the oceans will be up to 98cm by 2100. More than six hundred million people would be directly affected; corresponding to the number of people who will need to move to other cities or to other countries. In what conditions will this happen? With which consequences on the ecosystems? On the economy? On the international relations? Though this blog, I try to explore these problems.