You can make a difference in your town or your city, to the hurt being caused by climate chaos and the great extinction event! Reuse this information! This is the letter for week 11 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 to all the strike letters, see this story.
STRIKE FOR THE PLANET
because the rate of sea level rise is increasing much faster than predicted
Taking action won’t ever be “cheap,” easy, politically feasible, or pro-capitalist, so what are you waiting for? Saving anything is only going to get harder the longer you wait.
Pay attention, panic, and act like our lives depend on what you do today and tomorrow – because they do.
This week’s topic is the COASTLINE OF SAN FRANCISCO.
Melting land ice is increasing sea level elevation. To review:
Thermal expansion has caused 1.4 inches of sea level rise in the last 25 years.
Melting land ice contributed roughly another 1.6 inches.
The Antarctic Peninsula Ice Sheet holds 9 in. of additional sea level rise.
The West Antarctic Ice Sheet holds 10.5 ft. of additional sea level rise.
The East Antarctic Ice Sheet holds 197 ft. of additional sea level rise.
Greenland’s ice sheet holds 23.6 ft. of additional sea level rise.
Greenland’s ice is currently melting 4X faster than it was in 2003.
The overall rate of sea level rise is currently accelerating by about 1/10th of an inch per year.
Studies since the 2014 IPCC report call 6.6 - 8.9 ft of sea level rise by 2100 plausible.
Historically, studies of melt rates and sea level rise tend to be conservative and provide gross underestimates.
Clearly San Francisco is already and will continue to lose coastal land.
The topo map below will help with visualizing this.
Everything in drab green, between 0 and 100 ft above sea level, should be considered at immediate risk.
This is because simple sea level rise data doesn’t take into account storm surges, king tides, and the effects of massive storms the SF coast is newly and increasingly vulnerable to (the Eastern Pacific hurricanes are moving ever northward, and the Accumulated Cyclonic Energy of these storms is breaking records.)
If you’d like to tease the flooding data out a little more, each line inside a specific color represents 20 ft of elevation difference.
A local artist (BurritoJustice) mapped what 200 ft rise of sea level in SF will look like. Please note that a total land ice melt will add 231 ft of water to sea level. Again, this is only simple sea level rise.
This is why San Francisco must plan for retreating from the coasts now.
When the ice melts, we will lose the majority of land in San Francisco. We can reduce these loses by planning how to deal with them, both temporarily and sequentially.
Temporarily, we need to increase the ability of the land to absorb water. While liquefaction is a danger, the push to eliminate unreinforced masonry buildings and to retrofit multi-family dwellings should go a long way to reducing damages from liquefaction in an earthquake. On the other hand, increasing ground water and the sponginess of the land will reduce both the amount of water flooding into the city and the strength of the waves when they hit. This can be accomplished by:
Planting marshes on the bay side, and sea grasses, kelp, and dune grasses on the ocean side,
Enforcing and expanding the requirement that every house have exposed permeable surfaces,
Installing bioswales everywhere,
Zoning for green roofs and walls, and charging continuous high fees for non-compliance,
Creating more parks, green corridors, and buffer zones,
Making all roads, sidewalks, and other ground level surfaces permeable,
And eliminating pesticides and the destruction or replacement of native bio materials.
Sequentially, SF must plan for permanent retreat. Not only must temporary infrastructures retreat uphill with us to protect the remaining land, but we must deal now with issues in these soon-to-be flooded lands. These issues include:
- Sewage
Much of the Oceanside Treatment Plant is at sea level, on sand or in the berm. The Southeast Treatment Plant is at sea level. The North Point Wet Weather Facility is at sea level and on the water.
- Energy Grid
What happens when substations flood? When will areas be permanently cut off? How? Can the grid be sustained? How? How much energy production can be moved to high land and made local now?
- Houses
Houses washed off foundations become tide-driven battering rams.
- Skyscrapers
Are foundations and lower story materials sufficient to withstand the increased pressures and corrosion from being submerged? If not, how will they be dealt with?
- Transport
What happens when MUNI and BART tunnels are underwater?
- Food
How will food get to SF? From where? Where in SF can food be produced? How much? Starting when?
- Water
How much of the Hetch Hetchy Project is endangered by rising sea level, especially pipelines 1 and 2?
- Refugees
What medical, housing, education, job, and other assistance will available for the flood zone refugees?
There’s so much more to consider. We plan now or we reap the chaos of not planning in the very near future.