The Beach: Coming soon to a neighborhood near you?
About 18,000 years ago, at the end of the last ice age, sea level was around 350 feet lower than it is today. The ice has been melting and the sea has been rising ever since. For the first 10,000 years or so the rise was pretty rapid, but for the past 8,000 years the pace has been much more gradual – an average of about a tenth of an inch per year.
While a 10 inch per century increase in sea level is still fast enough to be noticeable in a human lifetime (at least in the lifetime of a human who stays put and pays attention) it is also slow enough to create a convenient and comforting illusion that the shoreline is a fixed feature of the landscape.
What all this means is that even without global warming, much of Central California’s most valuable real estate was already doomed to slide slowly into the waves. Global warming is merely accelerating the process – and the only real question is just how hard that acceleration is going to be.
As estimates of future sea level rise are necessarily based on attempts to predict things like the behavior of poorly understood mid-ocean currents and the rate at which ice will melt and slide off Greenland and Antarctica, we wouldn’t put a lot of faith in anyone’s figures. All we know is that the longer the research goes on, the bleaker the predictions seem to become. A one meter rise in sea level over the next 100 years now seems to be accepted as a reasonable projection, while less conservative scientists are already talking about the possibility of a rise as great as 7 meters (over 20 feet).
Should that current worst case scenario actually occur, children alive today could easily live to see most of downtown Monterey destroyed, Sand City and Castroville wiped out entirely, and a new beach formed along the edge of the City of Salinas.
But that’s all pretty speculative, so let’s not worry about it now. What is virtually certain is that shoreline structures already in the danger zone are going to be destroyed and that salt water intrusion of the fresh water aquifers we depend on for drinking and irrigation water is going to become more and more difficult to stop.