IPCC Fourth Assessment Report: Climate Change 2007
Climate Change 2007: Working Group II: Impacts, Adaptation and Vulnerability

7.4.3 Key vulnerabilities

As a general statement about a wide diversity of circumstances, the major climate-change vulnerabilities of industries, settlements and societies are:

1. vulnerabilities to extreme weather and climate events, particularly if abrupt major climate change should occur, along with possible thresholds associated with more gradual changes;

2. vulnerabilities to climate change as one aspect of a larger multi-stress context: relationships between climate change and thresholds of stress in other regards;

3. vulnerabilities of particular geographical areas such as coastal and riverine areas vulnerable to flooding and continental locations where changes have particular impacts on human livelihoods; most vulnerable are likely to be populations in areas where subsistence is at the margin of viability or near boundaries between major ecological zones, such as tundra thawing in polar regions and shifts in ecosystem boundaries along the margins of the Sahel that may undergo significant shifts in climate;

4. vulnerabilities of particular populations with limited resources for coping with and adapting to climate-change impacts;

5. vulnerabilities of particular economic sectors sensitive to climate conditions, such as tourism, risk financing and agro-industry.

All of these concerns can be linked both with direct effects and indirect effects through inter-connections and linkages, both between systems (such as flooding and health) and between locations.

Most key vulnerabilities are related to (a) climate phenomena that exceed thresholds for adaptation, i.e., extreme weather events and/or abrupt climate change, often related to the magnitude and rate of climate change (see Box 7.4), and (b) limited access to resources (financial, technical, human, institutional) to cope, rooted in issues of development context. Most key vulnerabilities are relatively localised, in terms of geographic location, sectoral focus and segments of the population affected, although the literature to support such detailed findings about potential impacts is very limited. Based on the information summarised in the sections above (Table 7.3), key vulnerabilities of industry, settlement and society include the following, each characterised by a level of confidence.

Table 7.3. Selected examples of current and projected climate-change impacts on industry, settlement and society and their interaction with other processes.

Climate Driven Phenomena  Evidence for Current Impact/ Vulnerability Other Processes/ Stresses Projected Future Impact/ Vulnerability Zones, Groups Affected 
a) Changes in extremes 

Tropical cyclones, storm surge


Flood and wind casualties and damages; economic losses: transport, tourism, infrastructure (e.g., energy, transport), insurance (7.4.2; 7.4.3; Box 7.3; 7.5)


Land use/ population density in flood-prone areas; flood defences; institutional capacities


Increased vulnerability in storm-prone coastal areas; possible effects on settlements, health, tourism, economic and transportation systems, buildings and infrastructures


Coastal areas, settlements and activities; regions and populations with limited capacities and resources; fixed infrastructures; insurance sector


Extreme rainfall, riverine floods


Erosion/landslides; land flooding; settlements; transportation systems; infrastructure (7.4.2)

(see regional Chapters)


As for tropical cyclones and storm surge, plus drainage infrastructure


As for tropical cyclones and storm surge, plus drainage infrastructure


As for tropical cyclones and storm surge, plus flood plains


Heat or cold-waves


Effects on human health; social stability; requirements for energy, water and other services (e.g., water or food storage), infrastructures (e.g., energy transportation) (7.2; Box 7.1;;


Building design and internal temperature control; social contexts; institutional capacities


Increased vulnerabilities in some regions and populations; health effects; changes in energy requirements


Mid-latitude areas; elderly, very young, ill and/or very poor populations




Water availability, livelihoods; energy generation; migration,; transportation in water bodies (;;


Water systems; competing water uses; energy demand; water demand constraints


Water resource challenges in affected areas; shifts in locations of population and economic activities; additional investments in water supply


Semi-arid and arid regions; poor areas and populations; areas with human-induced water scarcity

b) Changes in means 



Energy demands and costs; urban air quality; thawing of permafrost soils; tourism and recreation; retail consumption; livelihoods; loss of melt water (;;;


Demographic and economic changes; land-use changes; technological innovations; air pollution; institutional capacities


Shifts in energy demand; worsening of air quality; impacts on settlements and livelihoods depending on melt water; threats to settlements/infrastructure from thawing permafrost soils in some regions


Very diverse, but greater vulnerabilities in places and populations with more limited capacities and resources for adaptation




Agricultural livelihoods; saline intrusion; tourism; water infrastructures; energy supplies (;;


Competition from other regions/sectors. Water resource allocation


Depending on the region, vulnerabilities in some areas to effects of precipitation increases (e.g., flooding, but could be positive) and in some areas to decreases (see drought above)


Poor regions and populations


Saline intrusion


Effects on water infrastructures (


Trends in groundwater withdrawal


Increased vulnerabilities in coastal areas


Low-lying coastal areas, especially those with limited capacities and resources


Sea-level rise


Coastal land uses; flood risk, water logging; water infrastructures (;


Trends in coastal development, settlement and land uses


Long-term increases in vulnerabilities of low-lying coastal areas


As for saline intrusion,

c) Abrupt climate change 


Analyses of potentials


Demographic, economic, and technological changes; institutional developments


Possible significant effects on most places and populations in the world, at least for a limited time


Most zones and groups


Orange shading indicates very significant in some areas and/or sectors; yellow indicates significant; white indicates that significance is less-clearly established.

  • Interactions between climate change and urbanisation: most notably in developing countries, where urbanisation is often focused in vulnerable areas (e.g., coastal), especially when mega-cities and rapidly growing mid-sized cities approach possible thresholds of sustainability (very high confidence).
  • Interactions between climate change and global economic growth: relevant stresses are linked not only to impacts of climate change on such things as resource supply and waste management but also to impacts of climate change response policies, which could affect development paths by requiring higher cost fuel choices (high confidence).
  • Increasingly strong and complex global linkages: climate-change effects cascade through expanding series of international trade, migration and communication patterns to produce a variety of indirect effects, some of which may be unanticipated, especially if the globalised economy becomes less resilient and more interdependent (very high confidence).
  • Fixed physical infrastructures that are important in meeting human needs: infrastructures susceptible to damage from extreme weather events or sea-level rise and/or infrastructures already close to being inadequate, where an additional source of stress could push the system over a threshold of failure (high confidence).
  • Interactions with governmental and social/cultural structures that are already stressed in some places by other kinds of change: examples include population pressure and limited economic resources, where in some cases structures could become no longer viable when climate change is added as a further stress (medium confidence).

In all of these cases, the valuation of vulnerabilities depends considerably on the development context. For instance, vulnerabilities in more developed areas are often focused on physical assets and infrastructures and their economic value and replacement costs, along with linkages to global markets, while vulnerabilities in less developed areas are often focused on human populations and institutions, which need different metrics for valuation. On the other hand, vulnerabilities to physical and economic costs can have a greater proportional impact in developing areas.

Although it would be useful to be able to associate such general vulnerabilities with particular impact criteria, climate-change scenarios, and/or time frames, the current knowledge base does not support such specificity with an adequate level of confidence.