What is Risk ? What is Hazard ? What is Exposure ? What is Vulnerability ? What is Sensitivity ? What are the different types of risk analysis method followed in any type of risk assessment works? After going through the presentation one can understand the answer to all the above questions.

1. What is Risk and
Vulnerability
Dr.Mrinmoy Majumder
Mrinmoy Majumder 1

2. Some Important Definitions/Terminologies which is
important for understanding the concept of CRA
• Hazard:
– In the context of climate change, hazard refers to any potential occurrence of a
natural or human-induced physical event that may cause damage to property,
infrastructure, livelihoods, service provision, environmental resources etc. As an
example, as sea level rises, increased frequency of inundation of an area during
storm event is a potential hazard for a low lying coastal community.
• Risk:
– Risk is the potential for consequences where something of value is at stake and
where the outcome is uncertain, recognizing the diversity of values. Risk is often
represented as probability of occurrence of hazardous events (likelihood) or trends
multiplied by the impacts (or consequences) if these events or trends occur. Risk
results from the interaction of vulnerability, exposure, and hazard (IPCC 2014).
– As an example, as sea level rises, increased frequency (likelihood) of inundation (a
hazard) of an area during storm event can put the structural integrity of a nearby
infrastructure, such as road into a risk.
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3. Contd.
• Vulnerability:
– The propensity or predisposition to be adversely affected. Vulnerability
encompasses a variety of concepts and elements including sensitivity or
susceptibility to harm and lack of capacity to cope and adapt (IPCC 2014). As an
example, older populations are more sensitive to heat-stress and have limited
physical capacity to adapt, therefore highly vulnerable during a heatwave.
• Exposure:
– The term exposure refers to the degree to which a system is exposed to a given
hazard (e.g. sea-level rise). As an example, a coastal community in a low-lying area
can be exposed to certain degree of hazard of inundation during a storm event.
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4. Contd.
• Sensitivity:
• In the context of a risk assessment, the term sensitivity refers to the degree to
which a system is affected by, or responsive to a hazard.
• In other words, sensitivity captures the potential of a system to be impacted by
a hazard.
• Sometimes sensitivity is determined by the criticality of the service that the
system provides.
• For example, a community uses a road located close to the low-lying area of
the coast as its main access to a major hospital.
• In the past, this road has been inundated during a storm event making access
to the hospital difficult.
• Because the hospital provides such an essential service, this community should
be considered more sensitive to coastal inundation event.
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5. Types of Risk Assessment
• Natural hazards-based
approach
• Vulnerability-based
approach
• Source :
https://www4.unfccc.int/sites/
NAPC/Country%20Documents/
General/apf%20technical%20p
aper04.pdf
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6. Natural
hazards-
based
approach
• The natural hazards-based approach to assessing
climate risk begins by characterizing the climate
hazard(s) and can be written as:
• Risk = Probability of climate hazard x Vulnerability
• Hazard is generally fixed at a given level and used to
estimate changing vulnerability over space and/or time.
• For example, a flood of a given height or a storm with a
given wind speed may increase in frequency of occurrence
over time, increasing the risk faced (assuming that
vulnerability remains constant).
• Source :
https://www4.unfccc.int/sites/NAP
C/Country%20Documents/General
/apf%20technical%20paper04.pdf
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7. Vulnerability-
based
approach
• The vulnerability-based approach
begins by characterizing vulnerability
to produce criteria by which risk is
assessed, e.g., by assessing the
likelihood of exceeding a critical
threshold.
• Risk = Probability of exceeding one or
more criteria of vulnerability
• Fixing the level of vulnerability allows
the magnitude and frequency of
climate-related hazards contributing to
that vulnerability to be diagnosed.
• This is the “inverse method” as
described in Carter et al. (1994). While
commonly used in other disciplines,
this technique has not been widely
used for assessing climate change risks.
• Source :
https://www4.unfccc.int/sites/NAPC/Coun
try%20Documents/General/apf%20technic
al%20paper04.pdf
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8. Examples of Climate Hazards and
Vulnerability
Examples of climate hazards are tropical cyclones, droughts, floods, or conditions
leading to an outbreak of disease-causing organisms (plant, animal or human).
Probabilities can be associated with the frequency and magnitude of a given hazard,
or with the frequency of exceedance of a given socio-economic criterion (e.g., a
threshold).
Probability can range from being qualitative (using descriptions such as “likely” or
“highly confident”) to quantified ranges of possible outcomes, to single number
probabilities.
Vulnerability is broadly defined in TP3*. Here, we limit our use of the term
vulnerability to refer to climate vulnerability – specifically, the outcomes of climate
hazards in terms of cost or any other value-based measure. Specific vulnerabilities
(e.g., to drought, flood or storm surge) can also be assessed within the investigation
of more broadly based social vulnerability, as described in TP3.
*Adaptation Policy Framework(APF) Technical Paper(TP) 3 which
Assess Current Vulnerability
Source :
https://www4.unfccc.int/sites/NAPC/Country%20Documents/General/apf%20technical
%20paper04.pdf
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