Climate change vulnerability: diverging definitions

I'm writing a paper right on climate change, food security, and vulnerability for one of my classes. Vulnerability is a tough concept to define, but it's often used to assess the potential risks of climate change impacts. We can examine the consequences of these diverging measures of vulnerability by looking at visual representations of vulnerability assessments. The following figures are all global maps of vulnerability from different researchers and organizations. 


Figure 1 is the result of a 2011 academic research paper by Samson et al. The map represents their calculation of a global climate–demography vulnerability index based on climate models projections for 2050 (Samson et al., 2011). They combine climate models with bioeconomic models of population density, thus making a value-based claim that regions are more vulnerable when they exceed their “climate-consistent population growth” (Samson et al., 2011, p. 538). Image source. 

Figure 2 is from a private advisory firm called Maplecroft, and represents the results of their 2011 Climate Change Vulnerability Index (Maplecroft, 2010). Their methodology was unavailable, but they rank Bangladesh as the most vulnerable to climate change impacts in 2011. According to their website, this is “due to extreme levels of poverty and a high dependency on agriculture, whilst its government has the lowest capacity of all countries to adapt to predicted changes in the climate. In addition, Bangladesh has a high risk of drought and the highest risk of flooding” (Maplecroft, 2010). Their timeframe is based on current vulnerability as well as future adaptive capacity. Image source.

Figure 3 is based on results from a report prepared for the United Nations Office for Coordination of Humanitarian Affairs in collaboration with Maplecroft and CARE International (UNOCHA, 2008). While the entire report has multiple maps of different human and environmental indicators, this particular map is of the “overall human vulnerability index” with regards to climate risks in the next 20-30 years. This combined their assessment of natural vulnerability, human vulnerability, social vulnerability, financial vulnerability, and physical vulnerability. Interestingly, while the other maps in this report include developed countries, the maps related to vulnerability only include the Global South. Image source.

The diversity of results in these three maps represents the variability of climate change vulnerability, some of the value-laden assumptions about climate vulnerability and choice of timescale, and the overall difficulties in defining and assessing vulnerability.

Sources

Samson, J., Berteaux, D., McGill, B.J., & Humphries, M.M. (2011). Geographic disparities and moral hazards in the predicted impacts of climate change on human populations. Global Ecology and Biogeography, 20, 532–544.

United Nations Office for Coordination of Humanitarian Affairs (2008). Climate change and human vulnerability: Mapping emerging trends and risk hotspots for humanitarian actors. Discussion Paper. Geneva: Cooperative for Assistance and Relief Everywhere, Inc. (CARE).