EPA reviewed these comments; we note that these general statements were followed by several specific comments which we address in subsequent responses. With respect to the general claim, we disagree that the TSD does not present sufficient evidence of the link between climate change and impacts on coastal systems. We reviewed the TSD in light of these comments, and conclude that it summarizes robust evidence from the assessment literature regarding the observed and projected impacts of anthropogenic climate change to coastal areas. The established body of scientific assessment literature, as summarized in the TSD, finds that the likely effects of sea level rise associated with elevated GHG concentrations include, but are not limited to: 1) the loss of waterfront property and increased vulnerability to inundation hazards (Nicholls et al., 2007); 2) the loss of coastal wetlands (Field et al., 2007, and references therein); 3) saltwater intrusion into coastal sources of ground water in the United States and other world regions due to sea level rise combined with high rates of water withdrawal (Kundzewicz et al., 2007); and 4) more severe coastal flooding and erosion hazards (Nicholls et al., 2007).
We disagree that the TSD does not describe how increased storm surge will result in adverse impacts to coastal areas. Section 12 of the TSD explains that accelerated sea level rise in the future, along with the present storm and wave climatology and storm surge frequency distributions, suggests more severe coastal flooding and erosion hazards (Nicholls et al., 2007). Higher sea level provides an elevated base for storm surges to build upon and diminishes the rate at which low-lying areas drain, thereby increasing the risk of flooding from rainstorms (CCSP, 2009b). This will result in increased coastal inundation (land loss), erosion, infrastructure damage, and habitat loss.
Climatic Hazards and Impacts on Agricultural Practices …
- The cost of vulnerability reduction is less when it is a feature of the original project formulation than when it is incorporated later as a modification of the project or an "add-on" in response to a "hazard impact analysis." It is even more costly when it is treated as a separate "hazard project," independent of the original development project, because of the duplication in personnel, information, and equipment.