I’ve been on vacation this week, but I wanted to offer some brief notes on issues that have grabbed my attention.
First, a new report on sea-level rise along the West Coast is a must-read for anyone interested in climate change. The report, written by a committee of the National Research Council, is well organized to serve all levels of interest. Download the report on the National Academies website.
An initial summary at the beginning of the report provides an intriguing overview of the many factors that went into predicting future sea-level changes. Each chapter summary delves a level deeper. If you read the full report, you’ll gain an understanding of the uncertainty of every assumption that goes into calculating a range of possible scenarios.
According to the report, most of California is expected to experience a sea-level rise of a meter over the next century — greater than the worldwide average.
On the other hand, the change for Washington, Oregon and Northern California is likely to be about 60 centimeters over that same period. That is because tectonic forces are pushing up land masses north of Cape Mendocino in California — possibly faster than the sea is rising.
Over time, ocean levels in the Northwest will rise increasingly faster than uplift of the land, the report predicts. Eventually, a subduction earthquake could drop the land masses by a meter or more, suddenly raising the sea level dramatically in coastal areas.
Robert Dalrymple, who chaired the study committee, said in a news release:
“As the average sea level rises, the number and duration of extreme storm surges and high waves are expected to escalate, and this increases the risk of flooding, coastal erosion, and wetland loss.”
The report discusses effects on nearshore areas along the coast and in various estuaries. Some land areas in Puget Sound are rising while others are falling, which adds to localized variations beyond those caused by the shape and depth of the bays and tidal marshes.
