Color-coding climate risks in the Golden State

Tim Walton / Photo One

Wildfires can leave little to salvage for homeowners caught in harm's way.

Climate change will disproportionately affect California’s most disadvantaged and isolated communities, according to a recent report from the Pacific Institute.

By looking at a broad array of factors – from social indicators such as income and birth rates, to environmental ones such as tree cover and impervious surfaces – the Oakland-based think tank has found that 12.4 million Californians live in census tracts with high “social vulnerability” to climate change.

This vulnerability can play out in various ways, says Heather Cooley, co-director of the institute’s water program and a lead author of the report. “In low-income communities, many people may not have insurance,” Cooley told me. “So when a flood or fire hits their homes, they may not be able to rebuild. If they’re suffering from a heat-related illness, they may not be able to seek treatment and their health may deteriorate as a result.”

Other vulnerable populations such as students and the elderly, she pointed out, are less likely to have access to a car and are therefore more vulnerable in an event such as a wildfire or flood requiring immediate evacuation.

While the interplay between climate and demographics is complex, the report finds that many of the state’s poorest and most isolated communities – such as the unincorporated agricultural towns in the Central Valley – will be especially hard hit by rising temperatures. Another Pacific Institute study released this week found that climate change could increase California water demand by eight percent by 2100 — a scenario that will surely exacerbate problems for all California communities.

The vulnerability rankings can also be viewed in a color-coded map broken into individual census tracts. Green areas indicate zones of lowest hazard; yellow, medium; and red, high.

Pacific Institute

A new report and from the Pacific Institute plots California's most vulnerable communities to climate change.

A glance at the Bay Area section of the map reveals familiar patterns. The region’s industrial cities and neighborhoods – Richmond, Vallejo, West Oakland, Bayview-Hunters Point, San Leandro, East Palo Alto, for example – are mottled with red, indicating high vulnerability to a shifting climate.

It’s well known that residents in these low-lying areas — many of them poor people of color — live today amid heavy industrial emissions. In the years ahead, however, they will be faced with disproportionate risk of flooding from rising sea levels, according to the report. Elevation and income are not always predictors of future flood risk, however. Cooley points to Los Angeles.  There, she says, areas at greatest threat from sea level rise are in higher-income neighborhoods.

Other studies have used similar social vulnerability indices including the work of University of South Carolina professor Susan Cutter, but none have gotten it down to such fine detail, says Cooley.

“There’s been a lot of focus on how we’re going to be impacted by climate change,” she said. “This takes it to the next step and looks at who is going to be impacted by climate change. It helps us to better understand what policies need to be put in place and who we need to be thinking about.”