Climate change vulnerability has various interpretations. Vulnerability changes with the scale of observation and the system in question. A population as a whole may not be vulnerable to climate change, but a community within the population can be extremely vulnerable to climate change (if they live in the coast, for example). Similarly, human populations in a location may not be vulnerable, but the wildlife of that location may be.
Climate science and climate action policies have come up with three terms that now help determine the extent of climate change vulnerability, and a means to assign indicators to measure this vulnerability.
Exposure to climate change
Exposure is defined as the contact (often direct) between a “system” and the climate. The system is defined by the scale of observation; over a specific temporal and/or spatial extent. Common examples of exposure to climate risks include exposure to climate variations, extreme events, diseases and dip in agricultural productivity.
Consider a coastal community within 10 km from the sea. This community would be exposed to cyclones, rising sea levels and saltwater intrusion in aquifers.
Sensitivity to climate change
Sensitivity is the degree to which the system is affected by the exposure to risks. It assesses the dependence of the system to the abiotic and biotic factors in the environment that are affected by the risks.
Our coastal community would be more sensitive to cyclones if their livelihoods are dependent on sea-based tourism, or if there are no wind-resistant trees in their community space, or because they live in areas below the sea level (as is the case with New Orleans, USA).
Exposure and sensitivity to climate risks result in the “climate impact” on the system in question.
Adaptive capacity refers to the ability of an individual, household or community to develop resilience and adjust to the climate risks. This adaptive capacity is a function of access to financial, technical, educational, and community resources.
If our coastal community has access to early warnings of cyclones have the ability to move to higher ground fast, adjusting to the climate risk they are facing.
The relationship between the three terms…
The three aspects of a system can be combined to define the vulnerability to climate change.
In reality, the three aspects are highly interlinked. For example, increasing adaptive capacity also has the effect of reducing the sensitivity of the system to climate change. The coastal community in the previous examples may improve their community’s adaptive capacity by investing in an intensive tree plantation program that protects their livelihoods and assets from the cyclone. Building resilient infrastructure to reduce exposure to climate risks also decreases sensitivity of the community.
High vulnerability is defined as a situation where the exposure to climate risks is high, the sensitivity of the system is high and the adaptive capacity is low.
Climate change adaptation projects and programs around the world employ this mechanism of assessing climate change vulnerability, and accordingly define indicators and measures to improve the resilience of a community towards climate risks.
Categories: Climate Change