Chasing ice, rising seas
If you are among the shrinking number of climate change deniers, you might consider a visit to Alaska’s Glacier Bay where an extended family of tidewater glaciers have been in rapid retreat, especially during the last 20 years.
And had you the opportunity to revisit some of those frozen rivers over the course of a decade – as we have – you would likely be stunned by the difference in length and mass of the disappearing ice.
Alaska has some 100,000 glaciers – the greatest number of any place in the world – and scientists tell us that 98 percent of them are melting, representing a combined loss of 20 cubic miles of ice each year.
The loss is visible, dramatic, often stunning.
In the frozen Himalayan peaks, great rivers of ice birth the Mekong and Ganges, the Yangtze and Yellow Rivers, which supply the irrigation and drinking water for more than 1.5 billion people.
As those glaciers shrink, the water supply for nearly a quarter of the planet’s people becomes incrementally less reliable, predictable and secure.
And if you have wondered where all the water from all that melting ice goes, the answer is simple. It all ends up in the same place – the ocean, the one ocean that is pulsing ever higher along every shoreline of every continent on Earth.
This is not a remote, abstract impact, happening just to isolated islands in distant places or to third-world nations with unprotected coasts and insufficient infrastructure.
It is happening in America, very close to your own front door.
According to a map of sea level rise published last year by the Pacific Institute and reflecting estimates compiled by the National Academy of Sciences, the current scenario for a 100-year flood event – driven by storm surge, high tide and rising sea level (up some 8 inches since 1900) – shows Highway 37 from Sears Point to Vallejo underwater, with San Pablo Bay pushing up to Arnold Drive, flooding the Schellville Airport and turning the entire Sonoma Slough into a vast lake.
By 2050, sea level could rise an additional 4.5 to 24 inches and, by the end of this century, it is predicted to increase by another 16 to 54 inches. When and if that happens, Arnold Drive will be flooded in spots, Schellville will be under water as will portions of Fremont Drive and Ramal Road. Highway 37 will be submerged from the Napa River to about a mile west of 121, and again from Sears Point to Vallejo.
In Marin, Bel Marin Keys would become a lagoon and the bay would invade San Rafael as far west as D Street. Sausalito’s waterfront disappears, out in San Francisco Bay, Treasure Island vanishes beneath the waves and in the City, the Great Highway is inundated while Lake Merced merges with the sea as it pours through the San Francisco Zoo.
A minimum of 480,000 people and $100 billion of infrastructure will be put at risk if some version of this scenario holds true. So what to do?
First, go to the Sebastiani Theatre on Monday, Feb. 25, to see the stunning film, “Chasing Ice,” James Balog’s jaw-dropping footage of melting glaciers and ice sheets, sponsored by Transition Sonoma Valley.
Then read the just-released report by the Bay Institute (see the page 1 story) about a plan to armor the bay with “horizontal levees,” partnering with nature to restore tidal marshland as a bulwark against the rising sea.
That would be a good place to start.