Climate change is already negatively affecting the health of Marin residents and within 15 years attendant sea-level rise could threaten the county’s shoreline buildings, roads and original utility systems.

This was the sobering message Marin supervisors received after Supervisor Kate Sears requested an update on the local health impacts of climate change and efforts to prepare for sea- level rise.

“The important question to ask right now is when will climate change begin to affect the health of our community,” Kathy Koblick, a director in Marin County’s division of public health, told supervisors. “The answer is: it is now.

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“We know that the impacts of climate change threaten our health by affecting the food we eat, the water we drink, the air we breathe and the weather we experience,” Koblick said.

In her report Tuesday, she noted that over the last five years the county health department has issued at least seven health advisories due to conditions aggravated by climate change. The advisories ranged from alerts about air polluted by smoke to the presence of infectious diseases such as West Nile and Zika virus.

Koblick said many of the health impacts are the consequences of the extreme weather – floods, drought, and extreme heat – caused by climate change. The fallout can result in increased displacement from homes, injury, indoor mold, vector-borne and infectious disease, food insecurity due to lower crop yields and disruptions in food supplies, water contamination, and mental health impacts.

“We know we’re seeing an increase in hot days,” Koblick said. “We can map it out year after year so heat exhaustion, heat stroke and hyperthermia are things we’re concerned about.”

Extreme heat results in an increase in hospitalizations for cardiovascular, kidney and respiratory disorders, particularly asthma. It also increases pollen which aggravates allergies and asthma. Climate change has resulted in an increase in wildfires and these fires generate smoke, which also causes respiratory and cardiovascular illness, Koblick noted.

“We have seen a lot of that with the Sonoma County fires and the Butte and Camp fires,” she said. “We saw quite an impact on air quality in Marin County.”

Climate change is increasing the range and activity of ticks, birds, mosquitoes and other vectors that spread infectious diseases. These diseases include: West Nile Virus, Zika, Lyme disease, malaria, avian flu, Dengue fever, and typhus. Those who will suffer the greatest negative health effects will be Marin’s most vulnerable residents: older adults, young children, the disabled, the poor and people of color, Koblick said.

Supervisors also received an update on the Marin Bay Waterfront Adaptation and Vulnerability Evaluation, known as BayWAVE, an effort to predict the effects of sea level rise in Marin and to develop strategies to offset the consequences.

A vulnerability assessment released by the county in June 2017 showed that in just 15 years flooding due to sea-level rise could inundate some 700 buildings across 5,000 acres in Marin, affecting the lives of tens of thousands of residents.

The county’s Department of Public Works and Community Development Agency are currently preparing adaptation strategies.

The California Department of Transportation has given the county a $400,000 grant to address sea-level rise and flooding of Highway 1 in Southern Marin.

Last year, the county also received a $520,000 grant from the San Francisco Bay Restoration Authority to design a project that would restore 85 to 155 acres of natural wetlands around Deer Island in Novato and possibly make the area more resilient to flooding due to expected sea-level rise.

The proposed plan for Deer Island includes building “horizontal levees,” also sometimes referred to as living levees or ecotone levees. Instead of relying on a wall to keep water out, horizontal levees contour the ground at the water’s edge so that it gently slopes downwards. This provides for more natural transitions from open water to tidal mudflat to tidal marsh to transitional upland habitat, known as ecotone.

Horizontal or ecotone levees provide superior protection against sea-level rise because the gradual slopes and tidal marsh vegetation slow storm surges and absorb floodwaters.

Supervisor Damon Connolly said this is an area in which Marin can provide state and even national leadership.

Connolly said, “We’re moving away from the traditional flood control model.”