Climate change vulnerability
Climate change vulnerability is a concept that describes how strongly people or ecosystems are likely to be affected by climate change. Its formal definition is the "propensity or predisposition to be adversely affected" by climate change. It can apply to humans and also to natural systems. Issues around the capacity to cope and adapt are also part of this concept. Vulnerability is a component of climate risk. It differs within communities and also across societies, regions, and countries. It can increase or decrease over time. Vulnerability is generally a bigger problem for people in low-income countries than for those in high-income countries.
Higher levels of vulnerability will be found in densely populated areas, in particular those affected by poverty, poor governance, and/or conflict. Also, some livelihoods are more sensitive to the effects of climate change than others. Smallholder farming, pastoralism, and fishing are livelihoods that may be especially vulnerable. Further drivers for vulnerability are unsustainable land and ocean use, marginalization, and historical and ongoing patterns of inequity and poor governance.
There are many different notions of what it means to be vulnerable. An important distinction is between biophysical and social vulnerability. Biophysical vulnerability is about the effects of climate hazards such as heat waves, coastal flooding or tropical cyclones. Social vulnerability, on the other hand, is about the underlying political, institutional, economic and social factors within societies. These factors matter for how and why people are affected, and they put some people and places more at risk than others. People who are more vulnerable include those with low incomes, indigenous peoples, women, children, and the elderly.
Tools for vulnerability assessment vary depending on the sector, the scale and the entity or system which is thought to vulnerable. For example, the Vulnerability Sourcebook is a guide for practical and scientific knowledge on vulnerability assessment. Climate vulnerability mapping helps to determine which areas are the most vulnerable. Mapping can also help to communicate climate vulnerability to stakeholders. It is useful to carry out vulnerability assessments in advance of preparing local climate adaptation plans or risk management plans. Global vulnerability assessments use spatial mapping with aggregated data for the regional or national level.
Definition
Climate change vulnerability is defined as the "propensity or predisposition to be adversely affected" by climate change. It can apply to humans but also to natural systems, and both are interdependent. Vulnerability is a component of climate risk. Vulnerability will be higher if the capacity to cope and adapt is low.Climate vulnerability can include a wide variety of different meanings, situations, and contexts in climate change research. It has been a central concept in academic research and IPCC assessments since 2001.
The concept was defined in the Third IPCC report as "the degree to which a system is susceptible to, and unable to cope with, adverse effects of climate change, including climate variability and extremes".
Early studies focused on biophysical vulnerability to climate change. In other words, the effects of physical climate hazards such as a heat wave or heavy rain events. This direction of research was shaped by earlier natural hazards research and it emphasised physical changes and energy flows in the landscape. It aims to quantify and measure the impacts of an event on the environment and on people. Since vulnerability is interpreted here as the negative outcome of climate change on people or places, it is also sometimes referred to as 'outcome vulnerability'.
An alternative framing focuses on social dimensions of vulnerability that set the context in which climate change happens. These dimensions include the political, institutional, economic and social structures that interact with the physical climate changes. For example, water privatization might affect the ability of people to respond to drought. This direction of research was shaped by human security research and they focus on the current context or 'starting point' for the social and biophysical processes. They are sometimes also referred to as 'contextual vulnerability' approaches. Research in this area focuses on analysing the factors that "put people and places at risk and reduce capacity to respond". See the section on 'Causes' below.
In the Fifth IPCC report, the social context was emphasized. It noted factors such as wealth and employment, access to technology and information, societal values and the role of institutions to resolve conflicts or develop relations among states as important. Vulnerability was defined as a characteristic of people or places independent of physical events. The report included two additional definitions, one of contextual vulnerability and one of outcome vulnerability.
Vulnerability and exposure
In the climate change context, exposure is defined as "the presence of people; livelihoods; species or ecosystems; environmental functions, services, and resources; infrastructure; or economic, social, or cultural assets in places and settings that could be adversely affected.".In earlier definitions of vulnerability to climate change vulnerability was defined as a function of exposure, sensitivity and adaptive capacity. This changed during the Fifth IPCC cycle. In this report, exposure was defined as one of the three interacting elements of climate risk, rather than as one of the external drivers of vulnerability. This change had two main implications. First, it means that vulnerability is understood as independent of exposure but is contextual. Second, it means that vulnerability assessment could focus on indicators for sensitivity and adaptive capacity to understand the current system weaknesses. For example, weaknesses such as the high ground slope of a farmland or marginalization of households in a community would make people or places sensitive to climate impacts. This makes it important to select the most hazard-relevant indicators for any vulnerability assessment. For example, to assess the vulnerability of traditional coastal fishing communities to sea surge, 'distance of dwellings from sea' and 'elevation of dwellings from sea level' would be hazard-relevant indicators.
Types
Climate change vulnerability has a wide variety of different meanings and uses of the term have varied and evolved over time. The main distinction is between biophysical and social vulnerability:- Biophysical vulnerability is about the effects of physical climate hazards such as a heat wave or heavy rain events
- Social vulnerability considers the many political, institutional, economic and social structures that form the context for climate change
Biophysical or (physical) vulnerability
Physical vulnerability tends to focus on outcomes of monetary loss and disruptions. It is also sometimes defined as the "degree of loss" on a scale of 0 to 1. In this framework, for example, physical vulnerability to surface water hazards in mountain areas has been widely studied.
Social (socioeconomic) vulnerability
Social vulnerability is a more people-centred, holistic perspective on how and why people are affected by climate change. Vulnerability of ecosystems and people to climate change is driven by certain unsustainable development patterns such as "unsustainable ocean and land use, inequity, marginalization, historical and ongoing patterns of inequity such as colonialism, and governance". Therefore, vulnerability is higher in some locations than in others. Certain aspects within a region increase vulnerability, for example poverty, governance challenges and violent conflict. Some types of livelihoods are regarded as particularly climate-sensitive, resulting in a higher level of climate change vulnerability. These include for example smallholder farmers, pastoralists and fishing communities.At its basic level, a community that is economically vulnerable is one that is ill-prepared for the effects of climate change because it lacks the needed financial resources. Preparing a climate resilient society will require huge investments in infrastructure, city planning, engineering sustainable energy sources, and preparedness systems. From a global perspective, it is more likely that people living at or below poverty will be affected the most by climate change and are thus the most vulnerable, because they will have the least amount of resource dollars to invest in resiliency infrastructure. They will also have the least amount of resource dollars for cleanup efforts after more frequently occurring natural climate change related disasters.
Vulnerability for people of a certain gender or age can be caused by "systemic reproduction of historical legacies of inequality", for example as part of "colonial, apartheid, and poverty discrimination". Social vulnerability of people can be related to aspects that make people different from one another, and also the situational variables.
Other categories
Geographic, or place-based vulnerability to climate change is an important dimension. The most geographically vulnerable locations to climate change are those that will be impacted by side effects of natural hazards, such as rising sea levels and by dramatic changes in ecosystem services, including access to food. Island nations are usually noted as more vulnerable but communities that rely heavily on a sustenance based lifestyle are also at greater risk.Around the world, climate change affects rural communities that heavily depend on their agriculture and natural resources for their livelihood. Increased frequency and severity of climate events disproportionately affects women, rural, dryland, and island communities. This leads to more drastic changes in their lifestyles and forces them to adapt to this change. It is becoming more important for local and government agencies to create strategies to react to change and adapt infrastructure to meet the needs of those impacted. Various organizations work to create adaptation, mitigation, and resilience plans that will help rural and at risk communities around the world that depend on the earth's resources to survive.