IPCC (2001) indicates that climate change will take place despite the mitigation strategies that are going to be implemented. This calls for adaptation strategies in order to reduce the vulnerability to climate change. The aim of this project was to make a policy assessment to contribute to a more thorough understanding of the adaptation options, their costs and benefits and the policy conclusions that could be attached to the results. The study is based on literature reviews, consultation of stakeholders and the design and implementation of a database with various options, and a first sketch of their incremental costs and benefits, either in quantitative of qualitative terms, and as far as current information allows. The study also pays attention to the institutional aspects by analyzing the role of the actors involved and the barriers and opportunities for implementing adaptation options.
The study shows that the Netherlands is particularly vulnerable to climate change in agriculture, ecosystems and the water system. The agricultural sector (including forestry and fisheries) is vulnerable to climate change and adaptation is necessary in these sectors. Detailed analysis of the various options is given in this Scientific Assessment and Policy Analysis (WAB) report. For the water system a wide variety of options exist and some of the adaptation options are already starting to be implemented. In addition, impacts will occur on ecosystems, but the options to adapt the management of ecosystems are limited other than considering the management of the national ecological network (NEN).
In order to adapt to climate change in a way that minimizes adverse environmental and economic impacts of both climate change and the adaptation options itself, a first need arises to assess the incremental costs and benefits associated with the different adaptation options. This requires consensus, at least to some extent, about the (un)certainty with which climatic impacts take place as different probabilities may lead to substantially different conclusions on what would be the best option to implement. The impacts of climate change are, even when only focussing on the Netherlands, surrounded by considerable uncertainties and its consequences are subject to debate. The report has dealt with this problem in two complementing ways. First the KNMI climate scenarios are used as a baseline (*). That is we take the estimated changes on their main indicators of climate change (including temperature, precipitation, and sea-level rise) as given. Secondly, given these scenarios we proceeded by reviewing the literature and consulting experts by means of a workshop. During the writing of the report two important observations were made. First, the literature on adaptation options for the Netherlands to date has a qualitative focus; to a very small extent costs of implementing the options have been roughly estimated, and their benefits are at best somewhat described in a qualitative way. Secondly, so far little attention has been given to spatial planning for the long run, i.e. for the period beyond 2050. This stresses the need for a more systematic research on and analysis of adaptation options, their costs and benefits, and their interactions.
We would like to emphasize that this report is based on climate scenarios that show a gradual change of the climate. This means that unexpected events, or very rapid climate change or issues such as the slow down of the North Atlantic gulf stream are not considered in this report.
(*) The new KNMI climate scenarios that were reported on 30 May 2006 were not yet available at the time of writing this report, but they do not affect the main adaptation options as described in this report, because the differences with other scenarios are relatively small.