Can we rise to the challenge of rising sea levels?

Imagine a darkened bedroom around midnight. You’re lying there in the silence waiting for sleep to come. From the direction of the closet comes a soft scuffling noise. Curious and maybe a bit alarmed, you sit up, but carefully; you don’t want to draw attention to your presence. Holding your breath, you wait, your head at a slight angle, the better to hear whatever it is.

There the noise is again, and again. It rattles the sliding door. It sounds bigger than a mouse, and unafraid. You’re the adult in the room. Now what? Panic? Quietly call 9-1-1, silly though your complaint may sound? Or lock the closet and bedroom doors, go downstairs, break out the cheese and crackers and turn on the TV?

This is roughly where we find ourselves in San Mateo County. The monster in the closet is rising sea level, an issue that humanity will be dealing with for at least the next 1,000 years, climate scientists say. Ocean levels are expected to rise 2 to 3 feet by the year 2100.

If steps are not taken in San Mateo County, salt water will cover the runways of San Francisco International Airport, flood the access points to the Dumbarton and San Mateo bridges, and threaten about $24 billion of infrastructure and property, including major corporations and the homes of about about 110,000 residents.

This catalog of consequences came up for discussion at a Dec. 9 conference at the College of San Mateo. About 300 people attended, including academics, elected officials, public works staff and members of the environmental community, said state Assemblyman Rich Gordon (D-Menlo Park). Mr. Gordon shared conference-hosting duties with U.S. Congresswoman Jackie Speier (D-San Mateo) and county Supervisor Dave Pine, whose district includes the airport.

Among the experts invited to talk: John Englander, an oceanographer; Will Travis, a former executive director of the San Francisco Bay Conservation and Development Commission (BCDC); Larry Goldzband, the current BCDC executive director; Maximilian Auffhammer, a professor of environmental economics at the University of California at Berkeley; and Julian Potter, the chief of staff at SFO.

The seas are warming faster than at any time in the last 500 million years, and it’s been 120,000 years since sea levels have been as high as they are right now, Mr. Englander told the assembly. Using ice cores extracted from ice sheets on Greenland and Antarctica, scientists have tracked 420,000 years of trends in sea level, global temperature and heat-trapping atmospheric carbon dioxide. It turns out that these three gradually, and in unison, change direction on 120,000-year intervals.

Such an interval is happening now, Mr. Englander said. According to a chart in his presentation, temperature and sea level are inconclusive, but not carbon dioxide. It is not only not showing indications of heading toward lower concentrations, it is rising straight up — literally off the chart.

How quickly sea level rises and its rate of rise depend significantly, but not exclusively, on future greenhouse gas emissions and the steps humanity takes to lower them, Mr. Englander said. There are wild cards: Massive quantities of methane lie frozen on ocean floors; if the water warms to the point at which that methane begins freely bubbling up to the surface, warming would accelerate dramatically.

In any case, humanity needs to get itself organized.

Let’s get regional?

Eleven Burlingame hotels serving the airport sit within a stone’s throw of the water. San Mateo County has nine waste-water treatment plants at sea level. U.S. 101 and Caltrain are at sea level, as are the corporate campuses of Oracle, Facebook and Genentech. As are Santa Clara County’s Google and Intuit, Yahoo and Lockheed Martin, Cisco and Intel, according to a map presented at the conference.

Is Silicon Valley capable of organizing for the betterment of the future of the Bay Area? As an entrepreneurial and venture capital magnet with renowned universities, high-performing school districts, unrivaled good weather, and secluded living in wealthy bedroom communities, it’s become a multifaceted economic powerhouse that more or less built itself. And rebuilds itself with each high-tech wave. Who needs regionalism?

And who needs California? How will the high-tech community respond to literal waves washing up on corporate campuses, on transportation infrastructure, on low-lying communities where employees live? Does technology somehow pull a rabbit out of the hat and come to the rescue? It hasn’t so far. Or does the powerhouse wind down as corporate loyalty to the region evaporates and the simple step of moving inland starts making sense? Centers of innovation in Texas, Illinois, North Carolina and elsewhere would be calling. Google is setting up operations on barges.

Perhaps it’s time that attention be paid. But by whom? And what will it take to get their attention? The threat is similar to that of a major earthquake, but it’s incremental rather than sudden. It also hasn’t happened, not only in San Mateo County but in 7,000 years of recorded human history. The remedies, including wetland rehabilitation, levees and sea walls, will be expensive and perhaps daunting in terms of getting buy-in from the tax-paying public.

With San Mateo and Santa Clara counties as the traditional geese laying the high-tech golden eggs, what is the role of the other seven Bay Area counties in a mutual aid situation? Losses along the San Mateo County coast and bay side would be 39 percent of total Bay Area losses essentially “ground zero,” Mr. Travis of BCDC said.

“It’s uncharted territory and there’s no point … in just becoming angry or finding blame,” Mr. Englander said. “It’s like anything else; it’s reality. While we may want to slow (emissions), we really need to begin to deal with the symptoms and what it means for how we live.”

“It’s the one thing that we need to plan for that’s going to change everything and that we have no prior experience with, and that’s what makes it different” he said. “We need to put sea-level rise in context and begin to envision a different world.”

Taking action

For years, efforts to slow global warming and climate change have focused on mitigation — lowering emissions of greenhouse gases such as carbon dioxide and methane, which trap heat in the atmosphere rather than letting it dissipate into frigid outer space. Adaptation to climate change was the focus on Dec. 9. Not that mitigation is unimportant, but that it is unrealistic to expect it to work in time.

To move toward adaptation, a collaborative conversation among local governments, nonprofit and for-profit organizations should begin in San Mateo County as it began two years ago in Alameda County, said Larry Goldzband of BCDC. The objective of Alameda County’s Adapting to Rising Tides (ART) program: a measurable strengthening of resilience to climate change among neighborhoods, cities, counties and regions.

“We’re doing this collaboratively in a non-regulatory way so that folks … will actually understand what will end up happening in their neighborhoods and can actually plan for it,” Mr. Goldzband said. “ART is successful because it’s non-threatening (and) it is non-regulatory (and) it is a flagship program nationally.” It doesn’t scare people into paralysis, but educates them to enable positive thinking, he added.

People need to understand what the projections of sea-level rise mean for day-to-day lives, said Maximilian Auffhammer, the UC Berkeley professor of environmental economics. It’s a matter of asking people to incur costs now for a return later.

The threat is not necessarily decades away, he said. Higher sea levels amplify the flooding potential of severe storms, as Hurricane Sandy demonstrated on the East Coast. Changes at the local level such as allowing homeowners to elevate their homes and rezoning areas vulnerable to extreme weather events are worthy of consideration, he said.

SFO will be reaching out to its immediate neighbors, including Millbrae and Burlingame, to talk about strengthening the defenses around the airport’s 8-mile circumference, said Ms. Potter, the SFO chief of staff. The airport has a $4.2 billion construction project going on and expects to create 36,000 jobs in the next decade, she said. “We’re investing for the Bay Area, for jobs, for the economy.” The airport recently paid $367 million in taxes on annual revenues of $5.5 billion, she said.

In Washington, D.C., a wellspring of federal assistance as well as a nexus of red tape and the province of skilled lobbyists, clout is currency. Conference panelists recommended establishing a federally funded county flood control district, as has been done in Sacramento. Congresswoman Speier said that would be a priority when she returned to Congress.

Wetlands, and their ability to absorb flood water and wave energy, are crucial, said Mr. Goldzband and Mr. Travis, his predecessor at BCDC. “Wetlands are about as close to magic as you’re ever going to get when you’re dealing with flooding,” Mr. Travis said. “The wider the wetland is at the front, the lower the levee can be at the back.”

There are limits. “Even if we find the necessary money to build all the levees, all the sea walls, all the pumps and all the infrastructure, we have to acknowledge that sea level will continue to get higher at an ever-accelerating rate in the future,” Mr. Travis added. “So eventually, we won’t be able to protect everything exactly the way it is today. At some point, levees aren’t viable.” At that point, we should look to the Dutch for lessons on how to live with high sea levels, Mr. Travis said.

“The fact that we encourage people to live and build in flood plains is, I think, problematic,” Supervisor Pine said. “What has been a 100-year (flood) event could easily become a 10- or 20- or 30-year event. I think we need to start moving, like the Dutch, towards a longer time horizon.”