Tide gauges show that global sea level has risen about 7 inches during the 20th century, and recent satellite data show that the rate of sea-level rise is accelerating. As Earth warms, sea levels are rising mainly because ocean water expands as it warms; and water from melting glaciers and ice sheets is flowing into the ocean. Sea-level rise poses enormous risks to the valuable infrastructure, development, and wetlands that line much of the 1,600 mile shoreline of California, Oregon, and Washington. As those states seek to incorporate projections of sea-level rise into coastal planning, they asked the National Research Council to make independent projections of sea-level rise along their coasts for the years 2030, 2050, and 2100, taking into account regional factors that affect sea level. Sea-Level Rise for the Coasts of California, Oregon, and Washington: Past, Present, and Future explains that sea level along the U.S. west coast is affected by a number of factors. These include: climate patterns such as the El Niño, effects from the melting of modern and ancient ice sheets, and geologic processes, such as plate tectonics. Regional projections for California, Oregon, and Washington show a sharp distinction at Cape Mendocino in northern California. South of that point, sea-level rise is expected to be very close to global projections. However, projections are lower north of Cape Mendocino because the land is being pushed upward as the ocean plate moves under the continental plate along the Cascadia Subduction Zone. However, an earthquake magnitude 8 or larger, which occurs in the region every few hundred to 1,000 years, would cause the land to drop and sea level to suddenly rise.

Although the extent of future sea-level rise remains uncertain, sea-level rise generally is anticipated to have a range of economic, social, and environmental effects on U.S. coasts. Global sea level is rising due to warming and expanding oceans, melting glaciers, and melting ice sheets in Greenland and Antarctica, among other reasons. From 1901 to 2010, global sea levels rose an estimated 187 millimeters (mm; 7.4 inches), averaging a 1.7 mm rise annually; estimates are that from 1992 to 2010, the rate increased to 3.2 mm annually. The rates of relative sea-level rise at specific locations are likely more important to coastal communities and coastal ecosystems than the global sea-level average trends. Sea levels are rising between 9 mm and 12 mm per year (0.4 inches to 0.5 inches per year) along the Mississippi delta near New Orleans and between 1 mm and 2 mm (0.04 inches and 0.08 inches, or less) per year along some coastal shorelines in Oregon and Washington. Since the beginning of the 20th century, coastal and tidal areas have seen significant population growth and associated development and infrastructure investments. The consequences of sea-level rise are of interest not only because of the local impacts on coastal communities and ecosystems but also because of the direct and indirect impacts and risks for the federal government. Following an introduction to sea-level rise issues, the report is divided into three primary parts: Part I describes the phenomenon of sea-level rise. It introduces key terminology, measurements, trends, and causes. Part II describes the types of effects that sea-level rise can have on U.S. coasts. It addresses effects on shorelines and coastal ecosystems and on coastal development and society. Part II describes federal actions to address sea-level rise and the tension between the federal role and actions taken by state, local, and private stakeholders. Part III provides a primer on policy considerations. It raises considerations and questions associated with policies to address the causes and effects of sea-level rise. It also discusses federalism issues and general considerations associated with sea-level rise policies and investments.

There are moments when we forget how fortunate we are to have the California coast. The state is home to 1,100 miles of uninterrupted coastline defined by long stretches of beach and jagged rocky cliffs. Coastal Sage chronicles the career and accomplishments of Peter Douglas, the longest-serving executive director of the California Coastal Commission. For nearly three decades, Douglas fought to keep the California coast public, prevent overdevelopment, and safeguard habitat. In doing so, Douglas emerged as a leading figure in the contemporary American environmental movement and influenced public conservation efforts across the country. He coauthored California’s foundational laws pertaining to shoreline management and conservation: Proposition 20 and the California Coastal Act. Many of the political battles to save the coast from overdevelopment and secure public access are revealed for the first time in this study of the leader who was at once a visionary, warrior, and coastal sage.

This book is a printed edition of the Special Issue "Climate Change, Coasts and Coastal Risk" that was published in JMSE

This book includes papers published in the Special Issue titled “Coastal Dynamic and Evolution”, which aimed to collect multidisciplinary studies that involved the evaluation of coastal evolution at different temporal scales, from hours and days to months and years, as well as historical changes. The volume contains investigations carried out by means of aerial photos and satellite images, as well as results from in situ surveys and observations aimed at assessing morphological changes in shoreline and dune systems as a consequence of chronic flooding and erosion processes or the occurrence of specific weather-related events. Studies on the evaluation of past and future sea-level variations and related impacts have also been included. In order to provide the reader with a wide overview of different coastal settings and methodological approaches, case studies from Russia, Italy, California (USA), Morocco, Spain, Indonesia, Ireland and Colombia have been included in this Special Issue. The content may be of interest to those who perform a wide range of investigations related to coastal analysis and management, especially to researchers and academics who can exploit the provided approaches and methodologies.