Climate Change and the Vulnerability Equation: Global North versus Global South

Rebecca SE Tan

6 December 2022

Introduction

Cities are vulnerable to climate change – extreme events such as droughts, wildfires, floods, and heat waves can greatly alter ecosystems, reduce food production, disrupt water supply, damage infrastructure, and increase mortality rates (Table 1) (Field, 2014). While damaging to both, these climatic events are felt differently by Global North versus South cities, due to their differing levels of vulnerability. Climate vulnerability is defined as “the degree to which a system is susceptible to, or unable to cope with” the adverse effects of climatic events (McCarthy et al., 2001). By comparing the vulnerabilities of Global North versus South via the exposure, sensitivity, and adaptive capacity framework (Kay, 2005), I argue that while both city types are similarly exposed, the higher sensitivity and lower adaptive capacity of Global South cities lead to their greater vulnerability.

Exposure

Exposure is the point of interaction between the external climate and a system, such as in the form of extreme climate events or diseases (Babu, 2019). This vulnerability factor seems to be of similar levels in both Global North and South cities (Fig. 1). For example, coastal communities worldwide are similarly exposed to rising sea levels and a greater frequency of saltwater intrusion and cyclones (Babu, 2019).

Climate exposure can come in different forms, such as changes in groundwater recharge, climate change induced diseases and deaths, marine biodiversity, and sea level rise (Conway et al., 2015; Field, 2014). One Global South case study is Quito, where climate change is severely impacting their water availability. Not only is there a reduction in surface and underground water due to glacier retreat, but they also face increased water usage from increased temperatures, and emerging conflicts around water scarcity (Hardoy & Pandiella, 2009). Similarly in the Global North, Toronto faces exacerbated threats of extreme heat, floods, droughts, new insect pests and vector-borne diseases (Bulkeley, 2013). As seen, though the form of exposure may be different, Global North and South countries are greatly affected by climate change.

Figure 1. Choropleth map of climate exposure, where the higher value represents the more vulnerable climate [Mean = 0.44, Std Dev = 0.08] (Sarkodie & Strezov, 2019).

Some argue that Global North cities may actually be more vulnerable due to a higher asset exposure. For example, estimates for New York and Miami suggest that the maximum damage of a huge hurricane could be between 10-25% of the gross regional product (Hunt & Watkiss, 2011). Similarly, total losses by flooding in Boston would exceed US$57 billion by 2100 (Hunt & Watkiss, 2011). However, while the current asset exposure of cities in developed countries may be greater, the fact that around 50% of Asia’s urban population lives in low-lying coastal zones cannot be understated (Bulkeley, 2013). Further, with the increasing wealth of Asian cities and other developing countries, the future asset exposure of these Global South countries will be humongous (Fig. 2). By 2050, the estimated annual loss from coastal flooding in just seven cities (Guangzhou, Mumbai, Shenzhen, Tianjin, Ho Chi Minh City, Kolkata, and Jakarta) is projected to reach over $32 billion (Dulal, 2018).

Figure 2. Map showing the top 20 cities with the highest predicted asset exposure to sea level rise in the 2070s (Hanson et al., 2010).

Sensitivity

Sensitivity is the responsiveness of a system to climatic influences – the degree to which a system is affected by its exposure (Schneider & Sarukhan, 2001). For example, coastal communities may be more sensitive to cyclones if there are few wind-resistant trees if they live below sea level, or majorly rely on sea-based tourism for income (Babu, 2019). While there are indeed exceptions (particularly physical ones such as New Orleans being below sea level), Global South cities in Africa and Asia tend to have higher sensitivity and hence higher vulnerability to climate change than Global North cities in Australia, Europe, and North America (Fig. 3). This higher sensitivity comes from factors such as natural capital, dependence on food and energy imports, need for external health provisions, as well as a greater urban concentration and slum population (Conway et al., 2015; Owusu & Asumadu-Sarkodie, 2016).

Figure 3. Choropleth map of climate sensitivity, where the higher value represents the more vulnerable climate [Mean = 0.40, Std Dev = 0.10] (Sarkodie & Strezov, 2019).

One prominent reason is the expansion of urban spaces in low- and middle-income cities into vulnerable zones, leading masses to occupy more affordable areas that are unsuitable for residential purposes (Rahman et al., 2015). Such unplanned development in areas prone to floods, tsunamis, landslides and even earthquakes can hence lead to greater loss of life and infrastructure when a disaster happens (Rahman et al., 2014). For example, the urban population in Latin America has expanded into mountain slopes, or into areas prone to flooding, sea surges and seasonal storms (Hardoy & Pandiella, 2009). Further, the informal nature of many of these settlements also means that people affected may suffer from inadequate municipal investments and the absence of political rights (Bulkeley, 2013). A similar condition exists in Lagos, where 70% of the population lives in slums with poor environmental conditions, particularly in flood-prone areas which sweep raw sewage and refuse into their homes on a regular basis (Adelekan, 2010).

That is not to say that cities in developed countries will not be affected, though in more indirect ways. For example, the sensitivity in Global South cities may break international supply chains and impact large multinational businesses (Maplecroft, 2018). For example, with Thailand producing most of the hard-disk computer drives worldwide, floods in Bangkok can unravel chains of global vulnerabilities (Carrington, 2011).

Adaptive capacity

Adaptive capacity is the system’s ability to adjust to climatic variabilities – such as that of individuals, households, or communities in minimising probable damage (McCarthy et al., 2001). For example, cities with access to early cyclone warnings can provide the public with valuable time to move to higher ground, hence reducing casualties and trauma. In this respect, Global North cities are much more prepared for climate risks, due to their greater access to financial, technical, and educational resources (Fig. 4) (Babu, 2019). Hence, their access to reliable drinking water, sanitation facilities, international engagement, transport infrastructure, and disaster training helps reduce their vulnerability (ND-GAIN, 2018).

Figure 4. Choropleth map of adaptive capacity to climate risks, where the higher value represents the more vulnerable climate [Mean = 0.51, Std Dev = 0.17] (Sarkodie & Strezov, 2019).

A prime example of such a Global North city is New York City. With technical and financial resources, the city has a Flood Hazard mapper, which provides information on current and future coastal flood hazards. This publicly available map can not only aid engineers and architects with their building plans but also help to better inform business owners and potential residents to be flood-vigilant (NYC Planning, n.d.). Further, the city also uses financial and technological resources for their Regional Heat Island Initiative, bringing scientists and policymakers together for deliberation (Rosenzweig et al., 2011). Through creating and analysing multiple regional climate models, the research was able to better inform different strategies for reducing the Urban Heat Island effect (Corburn, 2009).

Comparatively, the adaptive capacity of Global South cities tends to be poorer. An adaptation deficit occurs, particularly when the population of cities grow faster than their physical infrastructure can handle (Hunt & Watkiss, 2011). Indeed, while many cities in developing nations may recognise the need for building codes and urban services such as waste collection and disposal, they may not have the financial, institutional, or educational means to enforce them (Rahman et al., 2015; Samiullah, 2012). One example is the vulnerability of Mexico City to water availability – while the city’s population is set to grow by about 17.5% from 2005 to 2030, water availability is predicted to decrease by more than 11%, even under the assumption that rainfall does not further decrease (Romero-Lankao, 2010). This decrease is due to poor management of water supply, improper use and disposal of water and wastewater, including the manipulation of watercourses and drainage regimes while extracting too much water. At the same time, the city is also very susceptible to flood events due to the inadequacy and disrepair of the sewage and wastewater systems (Romero-Lankao, 2010). As a result, parts of the city such as Chalco and Netzalhualcoyotl are chronically flooded with sewage due to insufficient infrastructure provision (Romero-Lankao, 2010). Indeed, while there are instances of good adaptive capacity in Global South cities (such as community support and resilience against floods in Dhaka, Bangladesh), the infrastructural and technological support of Global North cities tends to triumph that of the Global South (Atta-ur-Rahman et al., 2016; Islam, 2022).

Further, it is important to note that adaptive capacities can also influence the exposure and sensitivity of a city. While I may have delineated these categories as separate theoretically (Fig. 5), the reality is much more interconnected. For example, the adaptive capacity of a city in investing in an intensive tree plantation program or resilient infrastructure can greatly reduce the sensitivity of a city as it protects livelihoods and assets from cyclones (Babu, 2019). Further, adaptive capacities such as financial resources and research can also prevent development in flood plains, a huge point of exposure for Southeast Asian cities (Carrington, 2011). As people continue to encroach on flood plains, the carrying capacity is further reduced, leading to even greater flood exposure (Atta-ur-Rahman et al., 2016). As such, adaptive capacity is perhaps the most significant factor in differentiating the lower vulnerability of Global North cities from that of the Global South.

Figure 5. Factors of climate vulnerability, namely exposure, sensitivity, and adaptive capacity.

Conclusion

Through an evaluation of the exposure, sensitivity and adaptive capacity of Global North and South cities, I argue that while climate exposure applies to every city, the lower sensitivity and higher adaptive capacities of cities in the Global North help to mitigate and reduce overall climate vulnerability. Indeed, research has shown that cities in Haiti, Bangladesh and Zimbabwe are amongst the most vulnerable, while cities in Iceland, the United Kingdom, Canada, and Germany are much better able to cope due to their strong economic, governance and social adaptation readiness (Carrington, 2011; Sarkodie & Strezov, 2019). While there are always exceptions, it is important to consider this vulnerability disparity when analysing policy planning or international agreements. Besides, our global networked connections necessitate us to fill these gaps, if not for moral reasons, then for the vulnerabilities in the system, including widespread disruption, conflict, and even geopolitical upheaval (Urry, 2009).

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