| 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 |
