Where to Resettle Californians?

We need to enable major densification of selected California cities to accommodate our own climate refugees.

Figure 1: East Bay Cities with Fire and Sea Rise Risks (map by Pietro)

Yesterday I pointed out that there are many cities and towns in the Coast Range and Sierra Nevada that will eventually have to be evacuated due to a permanent rise in fire risk. The State Insurance Commissioner can soften the financial blow through moratoria on insurance policy cancellations, but in the next several decades we will need to relocate several million Californians from areas that are too costly and risky to defend.

Where can we realistically resettle so many people? In Afghanistan in 2003 I saw the impact of an 18-month process of resettling 2 million people; so I know that it is possible and that the outcomes can be pretty difficult for those families. Where did Afghans resettle when they were compelled to return to Afghanistan from Pakistan and Iran? They resettled where there were jobs, resources, opportunities. In other words, about half of them settled in Kabul.

In California, where are the jobs and infrastructure? The Bay Area, Sacramento, Los Angeles, and San Diego. Which is a problem, because these cities are already very expensive and highly resistant to the process of densification. Furthermore, these cities also face severe fire risk. To take a closer look, consider Berkeley.

Figure 2: Berkeley with Sea Rise & CalFire State & Local Responsibility Areas.
(source for Oakland Firestorm extent: Dan Ryan; for 1923 Berkeley Fire: Berkeley Public Library)

In Figure 2, I show sea-rise to 6 feet (the current estimate for 2100 AD) and the fire risk zones. Sea-rise is a serious risk for many cities across the world. It will affect the North Bay and South Bay, but not much of Berkeley. However, fire risk in the Berkeley Hills is very high, and where the terrain is steep and the roads are limited, it has the same risks as Paradise. In the dark brick color I show the extent of the 1923 and 1991 fires that destroyed parts of Berkeley and Oakland; they affirm the CalFire risk maps.

The flatter parts of California cities can also burn, but they have a major risk advantage: a grid pattern of streets enables both evacuation of families, and access for firefighters and their equipment. In the map below, I derived slopes from the Shuttle Radar Topography Mission data to show areas of fire risk with different data:

Figure 3: Berkeley with slopes derived from SRTM v3 1 arc-second data (USGS)

Figure 3 reveals that all blocks north and east of Marin Circle are also hazardous. The terrain is steep and the roads are winding and narrow.

Implications for future resettlement

State politics in 2021 focus on making housing affordable under conditions as we understood them in 2012. What has not changed since 2012:

  • The 1922 Standard Zoning Enabling Act and the Federal Housing Authority both strongly promoted very-low-density detached single-family homes as the predominant pattern of American urbanization for a full century.
  • Bad-faith abuse of CEQA has suppressed statewide housing production since the 1972 Friends of Mammoth court decision.
  • Failure to reform banking and lending after the 2007 foreclosure/2008 global financial crisis means that banks continue to over-lend, enabling prospective buyers to bid more than they can afford.
  • Elimination of the Redevelopment Law in 2012 has reduced the supply of very-low-income housing, and a pre-existing crisi of evictions and unhousing has exploded.

For all those longstanding reasons, we need major up-zoning and massive house production to correct for 49 years of undersupply. SB 9 and SB 10 were good steps in this direction.

However, what has changed is that the number of regions where we can densify are constrained by fire risk, and to a lesser degree, the impending rise in sea level. Furthermore, my experience in Kabul made it very clear that any attempt to build dense settlements in areas with poor opportunities is a waste of effort and resources. If Chico has the jobs and infrastructure to absorb refugees from Paradise, that will be great. But I expect that many families will choose Sacramento or the Bay Area. Housing is scarcer and costs are higher in these larger cities; but most households weigh costs relative to opportunities and potential incomes.

Prepare to densify attractive urban districts by A LOT

Even though global population growth is leveling off, and even though Americans are becoming much less welcoming of immigrants, we will need to greatly increase the residential density of job-rich California cities. The geography of urban resettlement is constrained both by increased fire threat and the limited number of places with real job opportunities. We will also end up having a lot more open space and wilderness because we need to unsettle the many regions of California that are becoming infeasible for permanent settlement.

And one last thing: Berkeley needs to restore its open grid by removing the bollards that block so many intersections. We can replace them with traffic circles to tame neighborhood traffic, but we need to maintain all available evacuation routes because fires can spread very quickly.

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