As a resident of a low lying coastal area I was doubly interested to see this new N.O.A.A. report on coastal impacts from Climate Change. But then I'm far from alone since over half the US population lives in coastal counties when you include the Great Lakes. Here are some excerpts from the first third of this comprehensive 150 page report detailing of the multitude things and processes that are likely to be affected and altered by the problems associated with climate change and sea level rise.
Coastal Impacts, Adaptation, and Vulnerabilities pdf
Executive Summary
Physical Climate Forces
A changing global climate combined with intense human activity imposes additional stresses on coastal environments. Although the climate is warming at a global scale, the impacts and the timing of the impacts are highly variable across coastal regions. Some effects, such as rising sea level, are already evident in increased erosion of beaches, more frequent flooding from both rivers and tidal surge, and wetlands converting to open water. Sea surface temperatures have risen over much of the globe, and hurricane activity has increased over the past several decades, particularly in the Atlantic basin, although it is uncertain whether these storm changes exceed the levels expected from natural causes. In addition, increased uptake of atmospheric carbon dioxide by the oceans has increased ocean acidity that threatens coral reefs and shellfish. The primary driving forces are: sea-level rise, changes in temperature, precipitation, major storm events including waves, winds and currents, and changing ocean circulation patterns. These driving forces interact in complex ways with the landforms and infrastructure that make the coasts particularly vulnerable to many of the impacts of climate change.
Key Findings
• The coasts of the U.S. are home to many large urban centers and important infrastructure such seaports, airports, transportation routes, oil import and refining facilities, power plants, and military bases. All are vulnerable to varying degrees to impacts of global warming such as sea-level rise, storms, and flooding. High Confidence.
• Physical observations collected over the past several decades from the land, coasts,
oceans, and the atmosphere, as well as environmental indicators, show that warming and some related environmental changes are occurring globally at rates greater than can be expected due to natural processes. These climate-related changes are highly varied, but some are likely due in large part to anthropogenically increased atmospheric concentrations of greenhouse gases and altered land surface properties. High Confidence.
• Findings from many independent scientific studies conclude that these changes are
consistent with global warming. The primary changes observed are rising sea level and
average global air, land, and ocean temperatures; heightening temperature and precipitation extremes in some regions; and increasing levels of oceans acidification and
rates of glacier and ice sheet melt. High Confidence.
• Most coastal landforms, such as barrier islands, deltas, bays, estuaries, wetlands, coral reefs, are highly dynamic and sensitive to even small changes in physical forces and feedbacks such as warming, storms, ocean circulation, waves and currents, flooding, sediment budgets, and sea-level rise.High Confidence
• Sea level change and storms are dominant driving forces of coastal change as observed in the geologic record of coastal landforms. Increasingly, sea-level rise will become a hazard for coastal regions because of continued global mean sea-level rise, including possibly accelerated rates of rise that increase risk to coastal regions. As the global climate continues to warm and ice sheets melt, coasts will become more dynamic and coastal cities and low-lying areas will be increasingly exposed to erosion, inundation, and flooding. High Confidence.
• Global sea level rose at a rate of 1.7 millimeters/year during the 20th century. The rate has increased to over 3 millimeters/year in the past 20 years and scientific studies suggest high confidence (>9 in 10 chance) that global mean sea level will rise 0.2 to 2 meters by the end of this century. Some regions such as Louisiana and the Chesapeake Bay will experience greater relative rise due to factors such as land subsidence, gravitational redistribution of ice-sheet meltwater, ocean circulation changes, and regional ocean thermostatic effects. Other regions undergoing land uplift, such as Alaska, will experience lesser sealevel rise. High Confidence
• Observations continue to indicate an ongoing, warming-induced intensification of the
hydrologic cycle that will likely result in heavier precipitation events and, combined
with sea-level rise and storm surge, an increased flooding severity in some coastal areas, particularly the northeast U.S.. Moderate Confidence.
• Methane is a primary greenhouse gas. Large reserves of methane are bound-up in Alaska’s frozen permafrost. These are susceptible to disturbance and methane release if the Arctic continues to warm. The additional methane released may result in even greater greenhouse warming of the atmosphere. High Confidence.
It looks at hurricanes which are expected to decrease slightly in frequency and increase substantially in force and with more variability in the likely storm tracks. But hurricanes aren't the only storms increasing threats to our coasts.
This report has an enormous amount of research supporting its sobering conclusions, and I have only scratched the surface here. I urge you to read at least the first parts for yourself.
As we are confronted by these often unwelcome changes, we as a society must stop treating the symptoms of our changing climate as isolated disconnected events in a piecemeal fashion. We need a coordinated and substantial response to mitigate and reduce the scope of the problems we are creating for ourselves.