Description
This publication explores the potential costs for coastal adaptation from 2010 until 2050 in East Asia due to climate-induced sea-level rise and possibly more intense tropical cyclones. The results are estimates of possible adaptation needs, which illustrate the possible magnitude of adapting to the future impacts of climate change on three important coastal countries: the People’s Republic of China (PRC), Japan, and the Republic of Korea.

This study is part of the technical assistance Economics of Climate Change and Low Carbon Growth Strategies in Northeast Asia, financed by ADB and the Korea International Cooperation Agency.

Findings
The analysis explores the costs of three main protection responses to the impacts of climate change, which include

• sea-dike construction and upgrades with associated maintenance costs for sea-flood impacts;
• beach nourishment for beach erosion impacts; and
• raising of port areas to maintain their effective operation.

The analysis also considers a range of impacts and costs, including dryland and wetland loss, associated forced migration, and sea-flood costs with and without upgraded protection. The adaptation methods are applied using a standard methodology using criteria that select optimum or quasi-optimum rule-based adaptation strategies.
Assuming no adaptation measures were undertaken, the impacts by 2050 are significant. It is unlikely that coastal societies could tolerate such losses and an adaptation response based on protection seems plausible, as already explained.

From 2010 to 2050, the average annual adaptation costs are estimated to be up to $1.9 billion per year in the Republic of Korea, $2.3 billion in Japan, and $2.6 billion in the PRC. These costs are dominated by sea dikes—the capital costs of upgrade are largest (54%–73% of national average annual costs), but as the stock of dikes grows, maintenance costs also grow (21%–31% of national costs). In contrast, the costs of nourishment are relatively minor in the region (less than 6% of national average annual costs). The costs of port upgrade are significant in the PRC and Japan, and less so in the Republic of Korea (up to 15%, 10%, and 4% of national average annual costs, respectively). This reflects the importance of ports and imports and/or exports in the region.

For all three countries, the costs are minimum estimates as the national port data is incomplete. In the case of Japan, adding new national data roughly doubled the annual adaptation costs for the country.

Contents

• Executive Summary
• Introduction
• Methodology
• Results
• Discussion
• Conclusions
• Appendixes
• References