John Hanson Mitchell is the author of The Paradise of All These Parts: A Natural History of Boston. He is the author of numerous books and editor of the award-winning magazine Sanctuary, published by the Massachusetts Audubon Society.
Illustration by Rick Sardinha, with thanks to Sanctuary Magazine.
As soon as John Winthrop and his gang of Puritans landed on the little temporary island known to the locals as Shawmut, they started digging and delving and filling marshes and swamps and inlets to build more land. Nothing new in all that, it seems to be a habit of Western culture; Rome was constructed around the Pontine Marshes, the Dutch put up massive dikes to keep the North Sea at bay, and Venice was built on pilings set in the marshy Venice Lagoon.
Boston, as the Shawmut came to be called, was separated from the mainland by a narrow little strip of land (now, basically, Washington Street) that flooded in spring tides, creating a tight little island. By the 1650s, more tidal streams were channeled, more marshes were filled, and more land was created over the centuries—including the massive filling of the banks of the Charles to create the famous Back Bay.
But coastlines are a fickle things, always coming and going. There was at time, not that long ago as geologic time is measured, when Boston sat under a mile of ice. And there was also a time when you could have hiked out to Georges Bank. Now according to a new study by the National Academy of Sciences, Boston could once more be under water (literally, not financially). The town is one of many coastal cities, including New York and Miami, that could see high tides flooding commonly used streets and neighborhoods in the next decades or so as a result of rising sea levels created by global climate change. And more high water to come in the next fifty years.
The last time Boston flooded entirely was about 11,000 years ago, as a result of the melting of the glacier.
This time around, it will happen from the same reason—melting ice—only this time it will be the polar ice cap and the 600,000 square mile Greenland ice sheet. And this time around, it will be our own fault.