Immediate Effects
The state of California predicts up to 166 cm of sea level rise south of Cape Mendocino by the year 2100. As a largely coastal community, Marin County will have to adapt to these future conditions. Much of Corte Madera and San Rafael, parts of Larkspur and Mill Valley as well as the lower areas of Tiburon and Sausalito will be completely submerged. Since most of the areas that will return to the bay are densely populated, the most likely immediate result will be large population migration inland.
Above: Area around Redwood High School with 150 feet of sea level rise. (COPC)
Furthermore, major transportation routes will be destroyed. Highway 101 will be submerged forcing commuters to be directed inland. Other important infrastructure like the Marin General Hospital will also be in the flood area, forcing the operation to move or dam water out. The reconstruction of much of Marin's infrastructure will put strain on the county.
Financial Burden
As an expensive residential area, the flooding in Marin will lead to hundreds of millions of dollars of lost property. Many displaced people will likely seek compensation for their loss. The United States itself has been the largest greenhouse gas emitter for much of modern history, only recently surpassed by China. It might then be the responsibility of federal organizations like FEMA to compensate home owners. This will ultimately be a major issue as the government will have to determine who, if anyone, is ultimately responsible for Marin's sea level rise and thus liable to pay.
"Neumann et al. (2000) have estimated that a 0.5-m sea-level rise by 2100 could cause cumulative impacts to U.S. coastal property of US$20 billion to US$150 billion and that more extensive damage could result if climate change increases storm frequency or intensity."
- IPCC
In addition, the government of Marin will have to assume the cost of repairing damaged infrastructure and most likely often rebuilding further inland. This cost will be further burdened by the loss of financial capacity derived from lost tax revenue. However, without the necessary adaptations Marin will likely suffer economically as people will move to less affected areas.
Environmental Consequences
With such large parts of Marin becoming flooded by 2100, the populations of affected areas will have to settle further inland. These areas, like San Anselmo and Novato, will consequentially become much denser than they currently are. This on its own will entail environmental consequences as natural space is given up for residential purposes. It is also probable currently uninhabited portions of Marin will have to be developed for residential use. This encroachment on undeveloped land will put further strain on the populations of organisms who lived there. As their habitats shrink their numbers will likely also reduce.
Above: Gas station in New Orleans, LA after hurricane Katrina. (Greenpeace)
Furthermore, the water that floods areas previously used by humans will likely become contaminated. As seen in 2005 with hurricane Katrina, the multitude of anthropogenic materials used on land will pollute the water as it washes through. Gasoline, chemicals and general waste are some examples of unnatural materials that will pollute the flood water. This will most likely lead to San Francisco bay becoming dirtier as these contaminants spread in throughout the water.