You can make a difference to the hurt being caused by climate chaos and the great extinction event in your town or your city! How? Reuse, repurpose, and recycle this information. You can push your local politicians to act. It will make a difference!
This is the letter for week 180 of a weekly climate strike that went on for 4 years in front of San Francisco City Hall, beginning early March 2019. For more context, see this story. For an annotated table of contents of the topics for all the strike letters, see this story. Meanwhile…
STRIKE FOR THE PLANET
The water is rising
Reaction Guidelines for Coastal Retreat
This is a resource for coastal retreat. The goal is to have procedures to pick off the shelf and start putting in place when it’s too late to avoid disaster.
Will coastal retreat be necessary?
Yes. The bay shoreline and Treasure Island are mostly unconsolidated fill1, prone to slumping, liquifaction, and sinking (especially given building masses). The city and the Army Corps of Engineers are looking at hardening strategies, which do damage to adjacent shorelines, only work if the builders accurately guess maximum sea level/ storm surge/ tidal rise, and assume erosion doesn’t exist.2
Even for this work, most of the focus is on the bay shores, but more than the bay shores are in danger. Pacific kelp forests have been devastated by sea urchins, with many areas becoming urchin barrens. The lack of kelp forests results in wave speeds and increased shore impacts equal to those caused by removing barrier islands and mangrove swamps, and that are not noticed until disaster hits.
In other words, we will flood.
We have temporary evacuation plans
Planning for earthquakes means we already have plans to deal with major destruction of city infrastructure and housing stock. Plans for mass temporary shelters depend on NGOs like the Red Cross, mutual aide agreements, and FEMA, as well as on city resources. Areas for such shelters are well-established, provisions for establishing such shelters are regularly inventoried and on paper are up-to-date and adequate, and the consensus seems to be that, short-term, we can provide emergency shelter.
But the issue is long-term
The sea level rise we’re locking into place is, for our species, permanent. Earthquake plans assume rebuilding in the same areas, but permanent flooding due to sea level rise doesn’t allow for rebuilding in the same way.
SF has no plan for long-term evacuation, aka coastal retreat.
There are ways to delay and minimize coastal retreat
- Building with the water instead of trying to hold it back, for instance.
- Retreating from the coasts before floods force the issue.
- Planting flood protecting ecosystems like seagrass and kelp forests.
- Increasing surface permeability.
- Requiring bioberms and rain gardens.
These all would make a difference.
But we aren’t doing them
We need robust, not fragile. What we’ve got right now is fragile.
FOOTNOTES
1. Specifically sand fill and shoal sands, Young Bay Mud, and Old Bay Mud, dune sand, alluvium, colluvium, landslide debris, and Franciscan Complex bedrock 285 feet below ground, according to the “Treasure Island/ Yerba Buena Island Redevelopment Project Final EIR”, April 2011, https://sftreasureisland.org/ftp/2011%20FEIR/Volume%202%20-%20Chapters%20IV.I-VIII/10%20-%20IV.N.%20Geology%20FEIR.pdf.
2. John King. “S.F.’s plan to protect the city from sea-level rise will ‘set the stage for our future shoreline’”. San Francisco Chronicle. 11 October 2022. https://www.sfchronicle.com/sf/article/sf-bay-sea-level-rise-17500388.php.