What is vulnerability?

The IPCC (Intergovernmental Panel on Climate Change) refers to vulnerability as the propensity or susceptibility to harm. Vulnerability encompasses a variety of concepts or elements, including notions of sensitivity or fragility and the inability to cope and adapt.

The vulnerability of a population and a region, combined with its exposure and hazards, gives rise to risk.


The vulnerability index, an innovative tool

The notion of vulnerability may seem vast. The exposure of a country, of a population, to climatic hazards escapes at first glance a quantitative analysis and has thus for a long time remained abstract.

It was not until 2014 that a tool was created, making it possible to quantitatively estimate the environmental vulnerability of a country. Indeed, it is now possible to quantify vulnerability to climate change through a global index of human exposure to the risk of climate change: the World Risk Index (WRI). This index, defined by the United Nations University for the Environment and Human Security (UNU-EHS) and the Alliance Development Works, makes it possible to translate the risk of a human community to natural disasters as a percentage.



This index thus allows to shed a better light on the demands of vulnerable countries

  • by assessing the threats they incur
  • and allowing them to associate an indisputable figure with the world community.


South West Indian Ocean islands vulnerable to climate change



The vulnerability of the South West Indian Ocean islands is high: they are the third most affected region in the world.

This vulnerability, analyzed in the Knowledge Synthesis Note on Observed and Anticipated Climate Trends in the IOC Region, is translated into

  1. an increase in sea level, the first global threat,
  2. an increase in the variability of precipitation,
  3. an increase in the intensity of extreme weather events, particularly cyclone,
  4. and an increase in the temperatures of the air and the sea.


The vulnerability of the South-West Indian Ocean region, whose WRI index is yet to be calculated, can be quantified by the economic cost of disasters, mainly meteorological, which amounts to $ 17.2 billion on last thirty years. The results of the 2017 South West Indian Ocean – Risk Assessment and Financing Initiative, funded by the World Bank, confirm the vulnerability of this region to natural hazards. Indeed, between 1964 and 2014, Madagascar, the Union of the Comoros, Mauritius and Seychelles were affected by more than 100 natural disasters, including 94 related to hydrometeorological phenomena. Some 14.4 million people were affected.


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