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Waddell, Moura Co-Author New Assessment of Bay Area Climate Impacts

Last month, the state of California issued its latest assessment of the many challenges the state faces from climate change — including wildfires like those still raging throughout the state – and highlighted for the first time the regional impacts with nine deep-dive reports spearheaded by University of California scientists.

Half of the 24 authors of the San Francisco Bay Area Summary Report are from UC Berkeley, including Professor of City & Regional Planning Paul Waddell and Civil and Environmental Engineering Assistant Professor Scott Moura.

Announced on the first day of a three-day California Adaptation Forum in Sacramento, the Fourth Climate Change Assessment summarizes the impacts already being experienced around the state, estimates how much worse it will get by the end of the century, highlights adaptation programs now planned or underway at the local and state level and lists actions that the state should take to lessen the human, environmental and financial costs.

While California has taken major action to rein in statewide carbon emissions, which drive greenhouse warming and climate change, he said, dedicated funding and clear guidance to help the cities and counties adapt to rising sea levels, hotter temperatures, unpredictable rainfall and drought and year-round wildfires are still lagging.

The three earlier state climate change assessments were mainly compilations of technical reports by academic and state and federal researchers. The new assessment includes updated technical reports, but also nine regional reports, three topical reports – including one on the climate-change impacts on California Indian tribes – plus a statewide wrap-up.

The new assessment comes a few weeks before the Sept. 12-14 Global Climate Action Summit, which is expected to bring thousands of people to the Bay Area. Co-chaired by Gov. Jerry Brown, it is designed to celebrate emissions reductions already implemented around the world and serve as “a launchpad for deeper worldwide commitments and accelerated action from countries … that can put the globe on track to prevent dangerous climate change and realize the historic Paris Agreement.”

The San Francisco Bay Area Summary Report bullets the effects of climate change that residents are already experiencing:

  • The area’s average annual maximum temperature has increased by 1.7°F since 1950;
  • Coastal fog is less frequent;
  • Sea level in the Bay has risen 8 inches in the last 100 years;
  • The 2012-2016 drought drove statewide moisture levels to the lowest in more than 1,000 years and left a snowpack lower than seen in 500 years;
  • The 2015-16 El Niño storms created waves with energy 50 percent larger than average, driving unprecedented beach erosion;
  • The area burned in “large-fire” years in the Bay Area has steadily increased over the past 80 years.

The 2012-2016 record low snowpack resulted in $2.1 billion in economic losses and 21,000 jobs lost in the agricultural and recreational sectors statewide and exacerbated an ongoing trend of groundwater overdraft, the report notes.

What’s in store for the future? Even warmer temperatures, no matter how much greenhouse gas emissions are reduced. More “boom and bust” rain cycles, with very wet and very dry years. More intense winter storms, even as the average Sierra Nevada snowpack is projected to decline by over 80 percent by the last part of the 21st century. Between 2½ and 10 feet of additional sea level rise by 2100.

This means more energy use as air conditioning becomes essential, even along the cooler coast; more health impacts from pollution and disease; airports, roads, railways and waste water treatment facilities inundated by rising seas; electrical grids and natural gas pipelines imperiled by flooding; and greater socioeconomic and health inequality.

For the environment, some evergreen forests will turn into chaparral scrub; animals may get out of sync with their environment, leading to population declines; flooding will endanger wetland life, while wildfires and heat will threaten upland birds, mammals and amphibians. The San Francisco Bay ecosystem, hemmed in by development, will have little room to adapt as beaches, marshes and mudflats disappear.

Despite the doom and gloom, however, the report calls out 15 projects already operating to address these threats around the Bay, and calls for more such projects in the future. One example is the Bay Area Regional Reliability Project, in which the area’s largest water agencies have joined forces to develop a regional solution to improve water supply reliability for over 6 million area residents and thousands of businesses and industries.

Read the report in full here