Typically, we think of dry and wet climates as being distinct. But the East Bay of the future may experience devastating aspects of both.
Many climate scientists expect California to increasingly experience intense periods of drought this century, much like the bone-dry winters from 2011 through 2015. Researchers also predict that Mediterranean climates — like that of the Bay Area — will become drier overall as global temperatures rise.
But climate change will also bring more powerful storms, with intense periods of heavy rain, much like we had last winter, when five years of drought were followed by record-breaking rainfall in many parts of the state. And, of course, as global temperatures continue to go up, and the ice fields of Greenland and Antarctica recede, sea levels will rise, flooding coastal areas around the globe, including California.
Think of our future as being like Los Angeles, only with our coastal areas partially submerged, particularly during powerful storms.
“By 2050, it’s clearly going to be drier and warmer,” said Bill Stewart, a forestry specialist at UC Berkeley’s Department of Environmental, Science and Policy Management. Stewart said that during the coming decades, the East Bay’s landscape is expected to add more shrubland and lose forest, shifting “to vegetation that does better in drier terrain.”
Each decade, he said, Northern California’s climate seems to move about one to two counties southward. “The stuff behind Berkeley,” he said, referring to the landscape of the East Bay hills, “will look like what’s behind San Jose.”
During extended droughts, an increasing number of trees in the East Bay hills — redwoods, oaks, fir, eucalyptus — are expected to die, weakened by the lack of water and succumbing to disease and beetle infestations — much like what has been occurring in the Sierra Nevada. Scientist say that more than 100 million trees have died in the past several years statewide.
And when trees die, they will likely be replaced over time by shrubs that prefer a dry climate (think, manzanita). That process could also occur much faster in the East Bay hills if wildfires strike. Trees could simply not grow back.
Plus, as it gets drier and more trees die, the risk of wildfire soars. Last month, a group of scientists warned in the journal BioScience that California’s dead trees could fuel wildfires of unprecedented fury.
Of course, wildfires in the East Bay hills will wreak havoc beyond the trees and plants. Tens of thousands of people reside in what scientists call the wildland-urban interface — known as the WUI — in the East Bay and their homes and lives will be increasingly at risk in the dry decades ahead. The East Bay hills, of course, experienced such an inferno in 1991 when 25 people were killed and more than 3,000 homes were destroyed. The devastating Sonoma County blazes last fall were also examples of what can happen in and near the WUI. The fires began in dry wooded areas, but strong winds sent them roaring into urban areas of Santa Rosa, killing 24 people and destroying 6,500 structures.
Unfortunately, the wildfire threat will further intensify in the East Bay after the vegetation shifts, scientists say. “Shrubs are the most flammable vegetation we have in California,” Stewart told the Express last fall. “So, a shift to shrublands does not portend well for us in Northern California.”
Worried yet? No? Then let’s talk about the floods.
Scientists predict that by 2100, global sea levels will rise 2 to 8 feet. And so far, the previous lower-end predictions of climate change have turned out to be too conservative. Some scientists also warn that a rapid disintegration of Antarctica’s ice sheets could cause sea levels to jump 4 to 10 feet by century’s end.
John Radke, a UC Berkeley associate professor of City and Regional Planning, has been examining models of likely impacts from sea-level rise on the Bay Area and California. He said the real threat from higher seas in the region will come from powerful storm surges during periods of heavy rain and high tides. “The storms are going to be more frequent,” he said. “And the storms are going to be stronger.”
Storm surge events will flood coastal areas, inflicting costly damage on shoreline homes and infrastructure. Radke said that, in the coming decades, Bay Area transportation officials will probably have to abandon Interstate 880 through Oakland, because it won’t be worth repairing after it washes away repeatedly during floods. “If enough catastrophes happen, we might wake up,” he said.
Radke also has spent time in the Netherlands, where one third of the country is below sea level, studying its elaborate system of dikes and levees, which hold back the sea. He said the Bay Area could build levees in San Francisco Bay, but they would probably only delay the inevitable. Because of the area’s topography, levees won’t be able to hold back the rising seas for long, he said. “Building a levee is a Band Aid. It’ll get us through a decade or two or three.”
In other words, you might not want to buy coastal property in the Bay Area — if you expect to pass it down to your grandkids. That’s especially true along the bay’s east shore, from Richmond to Fremont, and, particularly, in Alameda. It’s not that the island will be underwater 24/7. But during storm surges? “I can tell you, I wouldn’t want to invest in the city of Alameda. My advice: If you own property there, sell it. Immediately,” said Radke, only half-jokingly.
But whatever you do, don’t head for the hills. Heavy rains on fire-ravaged hillsides equal disaster. Just ask the folks of Montecito, where 20 people perished in massive mudslides last month near Santa Barbara after a big storm dumped rain on wildland areas torched by the Thomas Fire — the state’s largest ever wildfire.
So, is too late? Yes and no.
Scientists say it is too late to stop rising temperatures and sea levels in the coming decades. We’ve already released too many greenhouse gases, and some global warming is now baked in. We can reduce some of the threats from future catastrophes, but we’ll have to drastically reduce our carbon footprint — and quickly.
That means building lots of dense housing near transit and job centers (but perhaps not right on the coastline) so that more people can take mass transit or walk to bike to work. We also have to stop building homes in the WUI.
And, of course, we have to stop burning fossil fuels.