The guidebook describes the 5-step process. Step 1: Assess vulnerability. The vulnerability assessment identifies numerous climate change risks and potential impacts to different sectors. Assessing a coastal area’s vulnerability to the impacts of climate change involves understanding: 1) the climate projections for a given religion or locale, 2) what is at risk (climate change exposure and sensitivity) and 3) the capacity of society to cope with the expected of actual climate changes  (adaptive capacity). Step 2: Select course of action. The first thing in selecting a course of action is to identify the priority climate change risks upon which to focus efforts and resources. Step 3: Mainstream coastal adaptation. It is important to recognize that climate changes adaptation presents a fundamental challenge to managing the coastal resources and should be “mainstreamed” into coastal management and developed at all levels. Step 4: Implement adaptation. It is important to strengthen legal framework and enforcement as well as personnel capabilities. Step 5: Evaluate for adaptive management. All evaluations of coastal adaptation measures involve a similar methodology and steps. The steps of the evaluation include the following: Specify evaluation questions, elaborate an evaluation plan, conduct the evaluation and communicate the results.

USAID: Adapting to coastal climate change: A guidebook for development planners, 2009 (Ref. Doc. 36)

The idea of the mainstreaming approach is to assess climate change impacts and vulnerabilities in the context of development. In a more simple way it can be said that the aim of mainstreaming assessments is to ensure that current, as well as future development policies, are well adapted to the climate and this can imply that some adaptation options are recommended. This way the mainstreaming approach aims at assessing the relationship between the climate and development in general, without giving specific consideration to distinguishing anthropogenic climate change impacts and vulnerabilities from climate vulnerability of development policies per se.  A stepwise mainstreaming approach for assessing adaptation can include 5 analytical elements: Element 1: Climate Conditions, Variability and Future Changes; Element 2: Selection of Development Indicators: Element 3: Assessing the Relationship between Climate Variables and Development Indicators related to Specific Activities; Element 4: Adaptation options; and Element 5: Assessment of adaptation options, in order to measure the costs and development impacts of implementing these options.

Development and Climate Change: A Mainstreaming Approach for Assessing Economic, Social, and Environmental Impacts of Adaptation Measures, Environmental Management, 43, 2009 (Ref. Doc. 39)

The local change in sea level at any coastal location depends on the global mean sea-level rise and regional deviations from this mean. Acceleration of the global-mean rise trend during the 20th century is difficult to detect because of the limited number of gauges with long records and the long period natural variability measured at each gauge.  Projections of future sea level need to include both the response to future emissions of greenhouse gases and the ongoing response to past emissions. This latter component is the commitment to sea-level rise and will continue for many centuries into the future, even if the concentration of greenhouse gases and aerosol particles in the atmosphere were stabilized immediately. Future sea-level rise can be estimated for different types of scenario using climate models of varying complexity.  In addition to rising sea levels, future global climate change is expected to directly alter many other environmental factors. Mean temperatures are projected to increase around the globe.  Mitigation will only significantly reduce the future rate and magnitude of sea-level rise after the middle of the 21^stcentury and the largest benefits occur long into the future. Unmitigated impacts could be significant and are reduced to varying degrees by mitigation. Hence based on the available knowledge, a combination of mitigation and adaptation are required in coastal areas and both policies need to be assessed in an integrated manner to develop a response to climate change. Such assessment should also include the immediate benefits of adaptation in terms of the increased capacity to deal with climate variability.

Benefits of mitigation of climate change for coastal areas, Global Environmental Change, 14, 2004 (Ref. Doc. 15)