Climate Change Vulnerability Index for Ecosystems and Habitats

Supporting Vulnerability Assessment and Adaptation Strategies at Regional ScalesData, Maps & Tools

Overview

The Index (“HCCVI”) is a framework for a series of measurements to determine how vulnerable a given community or habitat type might be to climate change. This index framework was piloted in the American southwest deserts focusing on characteristic terrestrial and aquatic community types.  First, specialists in each type conducted a series analyses for climate change exposure (forecasted effects of climate change), sensitivity (current ecological condition or health), and adaptive capacity (the ability to cope with climate stress).  

Field specialists were then gathered in a workshop to review and refine the assessments. They then documented potential strategies along a continuum from immediate “no regrets” actions to “anticipated” or “wait and watch” actions to monitor. By focusing on major natural community types within a given ecoregion, pragmatic strategies can be identified for application across multiple, neighboring managed lands.

Download the Documents

HCCVI Report

HCCVI Appendix 2

HCCVI Appendix 3

View recorded webinar and slides from the EBM Tools Network's Habitat Climate Change Vulnerability Index webinar on September 25, 2012.

Value

Land managers need a better understanding of factors that contribute to climate-change vulnerability of ecosystem and habitat types in order to formulate adaptation strategies. This framework and method serves as a habitat-based companion to the NatureServe Climate Change Vulnerability Index for species.  While the overall index score for each community should be useful for regional and national priority-setting and reporting, the results of these individual analyses should provide insight to local planners and managers for climate change adaptation.

Features & Benefits

The HCCVI aims to implement a series of measures addressing climate change exposure and ecological resilience for each community type for its distribution within a given ecoregion. Since quantitative estimates may not be feasible for all measures, both numerical index scores and qualitative expert categorizations may be used. The combined relative scores for exposure and resilience determine the categorical estimate of climate change vulnerability for 50 years into the future. Index measures are organized within categories of Exposure, Sensitivity, and Adaptive Capacity. A series of 3-5 measures, each requiring a separate type of analysis, produces sub-scores that are then used to generate an overall score for exposure vs. resilience (sensitivity + adaptive capacity). Main components are summarized below.

Climate Exposure - Analyses of exposure encompass the current and forecasted exposure to climate change and their likely effects on ecosystem-specific processes. These analyses include the identification of baseline climate conditions, including historical climatic variability, and future climate projections, including their departure from historical conditions, and the resulting implications for increasing ecosystem stress, changing dynamic processes (such as wildfire or hydrological regime), and changing species composition. For a given ecosystem type within an ecoregion, the base measure of exposure may be calculated, for each of a suite of seven ecologically relevant climate variables, the percent-area projected to experience significant departures from 20th century baseline values by midcentury (e.g., a 2040-2069 30 year average), incorporating a metric of the 20th century range of variability for each variable. Direct effects of sea level rise (e.g., loss of coastal marsh area) are considered here under exposure.

Climate Change Sensitivity – this addresses predisposing conditions affecting ecological resilience; i.e. the capacity of a system to absorb disturbance and reorganize while undergoing change so as to still retain essentially the same function, structure, identity, and feedbacks. Analyses of sensitivity consider human alterations to characteristic pattern and process, such as landscape fragmentation, effects of invasive species, or human alterations to dynamic processes. In the HCCVI process, these human alterations are considered independent of climate change, but once identified, have some potential interactions with forecasted climate change. These analyses also include a temporal dimension, considering both legacies of past land use along with current conditions.

Adaptive Capacity encompasses natural characteristics that affect the potential for ecological resilience in a changing climate.  Analyses consider the inherent variability in climate regime or topographic diversity for the distribution of a given ecosystem or community type. They also consider aspects of natural species composition, such as the relative diversity within groups of species that provide functional roles, or the relative vulnerabilities of individual species that provide “keystone” functions.