Synthesis Report - Question 3

Climate Change 2001: Synthesis Report

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3.31 Estimates of the costs of adaptation are few; the available estimates indicate that costs are highly sensitive to decision criteria for the selection and timing of specific adaptation measures. The costs of measures to protect coastal areas from sea-level rise are perhaps the best studied to date. Evaluated measures include construction of "hard structures" such as dikes, levees, and seawalls, and the use of "soft structures" such as nourishment of beaches with sand and dune restoration. Estimates of the costs of protecting coasts vary depending on assumptions about what decisions will be made regarding the extent of the coastline to be protected, the types of structures to be used, the timing of their implementation (which is influenced by the rate of sea-level rise), and discount rates. Different assumptions about these factors yield estimates for protection of U.S. coasts from 0.5-m sea-level rise by the year 2100 that range from US$20 billion to US$150 billion in present value.

WGII TAR Sections 6.5.2 & 18.4.3
3.32 Climate change is expected to negatively impact development, sustainability, and equity.

3.33 The impacts of climate change will fall disproportionately upon developing countries and the poor persons within all countries, and thereby exacerbate inequities in health status and access to adequate food, clean water, and other resources. As already noted, populations in developing countries are generally expected to be exposed to relatively high risks of adverse impacts from climate change on human health, water supplies, agricultural productivity, property, and other resources. Poverty, lack of training and education, lack of infrastructure, lack of access to technologies, lack of diversity in income opportunities, degraded natural resource base, misplaced incentives, inadequate legal framework, and struggling public and private institutions create conditions of low adaptive capacity in most developing countries. The exposures and low capacity to adapt combine to make populations in developing countries generally more vulnerable than populations in developed countries.

WGII TAR Sections 18.5.1-3
3.34 Non-sustainable resource use adds to the vulnerability to climate change. Conversion of natural habitat to human uses, high harvesting rates of resources from the environment, cultivation and grazing practices that fail to protect soils from degradation, and pollution of air and water can reduce the robustness of systems to cope with variations or change in climate, and the resilience of systems to recover from declines. Such pressures make systems, and the populations that derive goods, services, and livelihoods from them, highly vulnerable to climate change. These pressures are present in developed as well as developing countries, but satisfying development goals in ways that do not place non-sustainable pressures on systems pose a particular dilemma for developing countries.

WGII TAR Sections 1.2.2, 4.7, 5.1, 6.3.4, & 6.4.4
3.35 Hazards associated with climate change can undermine progress toward sustainable development. More frequent and intensified droughts can exacerbate land degradation. Increases in heavy precipitation events can increase flooding, landslides, and mudslides, the destruction from which can set back development efforts by years in some instances. Advances in health and nutritional status could be set back in some areas by climate change impacts on human health and agriculture. Hazards such as these can also be exacerbated by further development in inherently dynamic and unstable zones (e.g., floodplains, barrier beaches, low-lying coasts, and deforested steep slopes).

WGII TAR Section 18.6.1
3.36 Climate change can detract from the effectiveness of development projects if not taken into account. Development projects often involve investments in infrastructure, institutions, and human capital for the management of climate-sensitive resources such as water, hydropower, agricultural lands, and forests. The performance of these projects can be affected by climate change and increased climate variability, yet these factors are given little consideration in the design of projects. Analyses have shown that flexibility to perform well under a wider range of climate conditions can be built into projects at modest incremental costs in some instances, and that greater flexibility has immediate value because of risks from present climate variability.

WGII TAR Section 18.6.1
3.37 Many of the requirements for enhancing capacity to adapt to climate change are similar to those for promoting sustainable development. Examples of common requirements for enhancing adaptive capacity and sustainable development include increasing access to resources and lowering inequities in access, reducing poverty, improving education and training, investing in infrastructure, involving concerned parties in managing local resources, and raising institutional capacities and efficiencies. Additionally, initiatives to slow habitat conversion, manage harvesting practices to better protect the resource, adopt cultivation and grazing practices that protect soils, and better regulate the discharge of pollutants can reduce vulnerabilities to climate change while moving toward more sustainable use of resources.

WGII TAR Section 18.6.1

Figure 3-6: Adaptation and the average annual number of people flooded by coastal storm surges, projection for the 2080s. The left two bars show the average annual number of people projected to be flooded by coastal storm surges in the year 2080 for present sea level and for a rise in sea level of ~40 cm, assuming that coastal protection is unchanged from the present and a moderate population increase. The right two bars show the same, but assuming that coastal protection is enhanced in proportion to GDP growth.
WGII TAR Section 6.5.1

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