Vocabulary Definition


Process of adjustment to actual or expected climate and its effects.

Adaptive Capacity

The ability of systems, institutions, humans and other organisms to adjust to potential damage, to take advantage of opportunities, or to respond to consequences. 

Climate Hazard

Specific impactful event as related to the broader climate parameter category.

Climate Hazard Indicator

Specific climate values (TMax > 35C; Precip > 100mm; Freezing Rain > 30 mm, etc.) that are defined by their ability to impact an infrastructure system or component (i.e., exceed a threshold).

Climate Parameter

Broader categories of measurable climate conditions in relation to which specific climate hazards or indicators can be defined. Climate parameters include temperature, precipitation, sea-level rise, wind, etc.


Outcome of an event affecting objectives.


The presence of people, livelihoods, species or ecosystems, environmental functions, services, resources, infrastructure, or economic, social or cultural assets in places and settings that could be affected.


A distinct part of an asset or system. Could include physical, planning or human resources.


Chance of something occurring; within the context of climate risk assessment, the chance of a defined climate hazard over a given time horizon.


A collection of assets or policies that are characterized by different risks.


Measure of the chance of occurrence expressed as a number between 0 and 1, where 0 is impossibility and 1 is absolute certainty.

Residual Risk

Risk remaining after risk treatment.


The capacity to cope with a hazardous event, trend or disturbance, responding or reorganizing in ways that maintain their essential function, identity and structure.


Effect of uncertainty on objectives. This guide applies the following formula as a measure of risk. Risk = Exposure x Likelihood x Consequence.

Risk Appetite

Amount and type of risk that an organization is willing to pursue or retain.

Risk Tolerance

Readiness to bear the risk after risk treatment.

Risk Treatment

Process to modify risk.


Point beyond which a system, because of physical damage or failure, is deemed to be no longer effective or safe: Economically; Socially; Technologically; Physically; or Environmentally. Also known as tipping point. 


Propensity or predisposition to be adversely affected.

PIEVC Protocol terms used in this Guide are updated from the PIEVC Protocol to align with international risk management standards ISO 31000 and ISO 14090, and other risk assessment processes. Specific updates are noted in call-out boxes throughout the Guide.