There is a new survey coupling government data on altitude contours with the 2010 census to determine the areas, number of dwellings, and the number of people affected by projected sea level rises plus storm surges of from one foot to ten feet above the high tide line. The data was developed by Climate Central and the study is called Surging Seas. It has just been reported on in the science section of the NY Times. Storm surges of four feet are contemplated, and by 2050 they may reach five feet. I have seen top estimates for sea level rise of up to a meter and a half resulting from rapid melting of Greenland and Antarctic ice caps by the year 2100. That would be about five feet. The IPCC report of 2007 did not include the ice cap meltings because they did not have a definitive estimate of it. The sum of a five foot surge plus a five foot sea level rise gives ten feet, the maximum height included in the table. There is also a report on Surging Seas by Andrew Revkin in the NY Times, and another by Justin Gillis in the NY Times.
The survey was for the continental lower 48 states. At a sea level rise of 1 meter, plus a storm surge, 3.7 million Americans would be affected, spanning an area the size of Maryland. 89% of the rise would be in the states of Florida, Louisiana, California, New York, and New Jersey.
I want to present here first the Surging Seas data for the State of California, and for the counties of San Francisco and San Diego, and the cities of Los Angeles and Long Beach, compiled from separate files for each.
Rise in feet | California | San Francisco County | Los Angeles | Long Beach | San Diego County |
1 | 146,000 | 4,400 | 2,900 | 800 | 260 |
2 | 224,000 | 5,700 | 4,400 | 1,400 | 360 |
3 | 308,000 | 7,000 | 9,900 | 4,000 | 500 |
4 | 374,000 | 8,800 | 11,600 | 6,400 | 700 |
5 | 440,000 | 10,900 | 13,100 | 10,600 | 2,500 |
6 | 520,000 | 13,200 | 14,500 | 13,500 | 4,000 |
7 | 666,000 | 15,600 | 16,100 | 16,300 | 6,400 |
8 | 817,000 | 18,800 | 21,700 | 21,900 | 32,400 |
9 | 916,000 | 21,800 | 24,000 | 29,500 | 37,500 |
10 | 1,012,000 | 24,400 | 26,600 | 35,100 | 42,200 |
Now we present a table for San Mateo County, San Joaquin County, Alameda County, Orange County, and Santa Clara County, in the order of the population affected by sea level rise plus storm surge.
Rise in Feet | San Mateo County | San Joaquin County | Alameda County | Orange County | Santa Clara County |
1 | 61,000 | 28,000 | 12,000 | 11,000 | 6,600 |
2 | 78,000 | 43,000 | 26,000 | 15,000 | 9,800 |
3 | 85,000 | 53,000 | 37,000 | 40,000 | 12,600 |
4 | 91,000 | 66,000 | 47,000 | 56,000 | 15,800 |
5 | 97,000 | 75,000 | 57,000 | 69,000 | 20,200 |
6 | 108,000 | 87,000 | 72,000 | 81,000 | 26,700 |
7 | 117,000 | 132,000 | 98,000 | 93,000 | 34,300 |
8 | 123,000 | 151,000 | 113,000 | 112,000 | 42,200 |
9 | 129,000 | 163,000 | 126,000 | 122,000 | 49,600 |
10 | 135,000 | 173,000 | 139,000 | 130,000 | 57,800 |
Sea level rise has only been 8 inches since 1880. With the slowness of rise, people are already preparing. In California, we have large lengths of coast where rock barriers are in effect to prevent cliffs from coastal erosion. This is called “fortress California”. On Balboa Island where I walk each weekend, which is an island build of Newport Bay dredge, the earth is confined by a vertical steel wall. There is also a raised shore and a two foot flood wall. Also, all new housing is built on a solid two to three foot high foundation above the walking level. When storm surge is expected, the beach sand on many beaches is bulldozed into sand barriers. Over the long term, coastline beach level housing can be replaced by those with empty ground floors like they do in areas of Kauai.
Next, we present the total for Orange County, and then for Huntington Beach, Newport Beach, and Costa Mesa. Laguna Beach and Irvine have essentially no people affected by the sea level rise.
Rise in feet | Orange County | Huntington Beach | Newport Beach | Costa Mesa |
1 | 11,000 | 9,500 | 550 | – |
2 | 15,000 | 12,900 | 860 | – |
3 | 40,000 | 34,600 | 2,200 | 34 |
4 | 56,000 | 44,300 | 4,500 | 61 |
5 | 69,000 | 51,800 | 7,200 | 105 |
6 | 81,000 | 58,500 | 10,100 | 142 |
7 | 93,000 | 66,400 | 12,700 | 413 |
8 | 112,000 | 77,600 | 15,600 | 623 |
9 | 122,000 | 83,400 | 16,600 | 785 |
10 | 130,000 | 87,400 | 17,100 | 952 |
We see that sea level rise affects Orange County and Huntington Beach much more, by factors of six and four, than San Francisco County, Los Angeles or Long Beach. This should have long term political consequences in how to deal with the global warming that is causing the sea level rise. In the immediate term, we of course realize that Orange County politicians are mostly locked into man-made climate change denial or doubt, while those from SF, LA, and Long Beach are more interested in preventing it. We see that cities in Orange County will be more involved in adapting to it.