6.5. Socioeconomic Impacts of Climate Change
In the past decade, some progress has been made in evaluating potential socioeconomic
impacts of climate change and sea-level rise on coastal and marine systems.
This progress, however, has not been as substantial as that relating to biogeophysical
impacts; nor has it been especially comprehensive (Turner et al., 1995, 1996).
To date, emphasis has been in three areas. First, research has focused on the
coastal zone itself (we are not aware of any studies of the socioeconomic impact
of climate change on open-ocean marine ecosystems). Second, there has been an
emphasis on the potential socioeconomic impact of sea-level rise but little
on any other climate change variables. Third, emphasis has been on economic
effects, not on impacts on social and cultural systems. These emphases are evident
in the following review, in which we consider socioeconomic impacts initially
as a component of the methodology for vulnerability assessment and then through
economic cost-benefit analyses of coastal zones in general and infrastructure
developments in particular. In these cases, "benefits" derive from
the inclusion of adaptation optionsprimarily shore protectioninto
the analyses to derive some net cost. Finally, we consider attempts that have
been made to "value" natural systems, as well as the potential social
and cultural impacts of climate change.
6.5.1. Socioeconomic Impacts as Part of Vulnerability Assessment
In the SAR, Bijlsma et al. (1996) reviewed several country case studies that
had applied the IPCC Common Methodology for assessing the vulnerability of coastal
areas to sea-level rise. These case studies offered important insights into
potential impacts and possible responses. Many of the assessments emphasized
the severe nature of existing coastal problems such as beach erosion, inundation,
and pollution, as well as the effects of climate change acting on coastal systems
that already are under stress.
The Common Methodology defined vulnerability as a country's degree
of capability to cope with the consequences of climate change and accelerated
sea-level rise. The methodology of seven consecutive analytical steps allowed
for identification of coastal populations and resources at risk and the costs
and feasibility of possible responses to adverse impacts. The SAR also identified
the strengths and weaknesses of the Common Methodology. More recently, Klein
and Nicholls (1999) have evaluated the IPCC's approach and results, concluding
that the Common Methodology has contributed to understanding the consequences
of sea-level rise and encouraged long-term thinking about coastal zones. They
went on to develop a new conceptual framework for coastal vulnerability assessment
that identifies the main components of the natural system and the socioeconomic
system, as well as the linkages between them and climate change and other change
variables. This framework is outlined in Box 6-5.
In the SAR, data on socioeconomic impacts were derived from country and global
vulnerability assessment studies. Figures for several countries were given relating
to the population affected, capital value at loss, and adaptation/protection
costs (Bijlsma et al., 1996, Table 9-3).
For the coastal zone, the authors concluded that:
- There will be negative impacts on several sectors, including tourism,
freshwater quality and supply, fisheries and aquaculture, agriculture, human
settlements, financial services, and human health.
- The number of people potentially affected by storm-surge flooding is
expected to double (or triple) in the next century, ignoring potential adaptation
and population growth.
- Protection of low-lying island states and nations with large deltaic
areas is likely to be very costly.
- Adaptation to sea-level rise and climate change will involve important
tradeoffs, which may include environmental, economic, social, and cultural values.
Since the SAR, there have been several summaries of the socioeconomic results
of the vulnerability assessment studies, presenting data at local, regional,
and global levels. Examples include case studies of Poland and Estonia (Kont
et al., 1997; Zeider, 1997), the Philippines (Perez et al., 1999), Bangladesh
(Ali, 1999), Egypt (El-Raey et al., 1999), and The Gambia and Abidjan (Jallow
et al., 1999), as well as the regional analyses and global synthesis of Nicholls
and Mimura (1998). The initial global vulnerability assessment has been revised
on the basis of scenarios for global sea-level rise derived from the Hadley
Centre's HadCM2 ensemble simulations and HadCM3 simulations for GHG-only
forcing (Nicholls et al., 1999). This assessment indicated that by the 2080s,
the potential number of people flooded by storm surge in a typical year will
be more than five times higher than today (using a sea-level rise of 0.38 m
from 1990 to 2080) and that between 13 million and 88 million people could be
affected even if evolving protection is included. Broadly similar results are
given in the study undertaken by DETR (1999). However, they note that the flood
impacts of sea-level rise are reduced by emissions scenarios that lead to stabilization
of CO2. By the 2080s, the annual number of people flooded is estimated to be
34 million under the 750-ppm scenario and 19 million under the 550-ppm scenario.
Klein and Nicholls (1999) have categorized the potential socioeconomic impacts
of sea-level rise as follows
- Direct loss of economic, ecological, cultural, and subsistence values
through loss of land, infrastructure, and coastal habitats
- Increased flood risk of people, land, and infrastructure and the aforementioned
- Other impacts related to changes in water management, salinity, and biological
They also developed a methodology that has not yet been applied in any case
Box 6-5. Conceptual Framework for Coastal Vulnerability Assessment
In the scheme illustrated below, analysis of coastal vulnerability starts
with a notion of the natural system's susceptibility to the biogeophysical
effects of sea-level rise and its capacity to cope with these effects
(resilience and resistance). Susceptibility reflects the coastal system's
potential to be affected by sea-level rise; resilience and resistance
determine the system's robustness or ability to continue functioning
in the face of possible disturbance. Together, these factors determine
the natural vulnerability of the coastal zone.
Resilience and resistance are functions of the natural system's
capacity for autonomous adaptation, which represents the coastal system's
natural adaptive response. Resilience and resistance often are affected
by human activities, which need not only be negative: Planned adaptation
can reduce natural vulnerability by enhancing the system's resilience
and resistance, thereby adding to the effectiveness of autonomous adaptation.
The biogeophysical effects of sea-level rise impose a range of potential
socioeconomic impacts. This impact potential is the socioeconomic equivalent
of susceptibility; it is dependent on human influences. Socioeconomic
vulnerability is determined by the impact potential and society's
technical, institutional, economic, and cultural ability to prevent or
cope with these impacts. As with the natural system's resilience
and resistance, the potential for autonomous adaptation and planned adaptation
determines this ability to prevent or cope.
Dynamic interaction takes place between natural and socioeconomic systems.
Instead of being considered as two independent systems, they are increasingly
regarded as developing in a co-evolutionary way, as shown by the feedback
loop from the socioeconomic system to the natural system.
Sources: Klein and Nicholls (1999); Mimura and Harasawa (2000).