The U.S. Environmental Protection Agency released "Coastal Sensitivity to Sea-Level Rise: A Focus on the Mid-Atlantic Region" (SAP 4.1) on January 16, 2009. According to the report's abstract, rising sea level can inundate low areas and increase flooding, coastal erosion, wetland loss, and saltwater intrusion into estuaries and freshwater aquifers. Much of the United States consists of coastal environments and landforms such as barrier islands and wetlands that will respond to sea-level rise by changing shape, size, or position. The combined effects of sea-level rise and other climate change factors such as storms may cause rapid and irreversible coastal change. Coastal communities and property owners have responded to coastal hazards by erecting shore protection structures, elevating land and buildings, or relocating inland. Accelerated sea-level rise would increase the costs and environmental impacts of these responses.