The flood due to Global Warming risks California

Sea level rise compelled by global warming could flood parts of the California coast in coming decades. The report by an independent Oakland research group, the Pacific Institute, says that nearly half a million people statewide and 110,000 in Orange County could be at risk by the year 2100 under some climate change scenarios. In Orange County which means a 55 percent increase over those already known to be at risk for a 100-year flood.

The level of risk is going to increase in the future and there are folks already in the flood plain who are going to experience increased risk. It will reach higher and reach further inland in some cases. The strategy is to look at different sectors of the economy -agriculture, energy, water supply, forestry, parks, transportation. It helps the climate action team focus priorities for informed policy. The study says that the rise in sea level of four to five feet would place an additional 220,000 people statewide at risk in a 100-year flood event from 260,000 estimated to be at risk in 2000 to 480,000.Nearly a quarter of those would be in Orange County, the study says, although Los Angeles, Monterey, San Mateo, Sonoma and Ventura counties would have significant populations at risk as well.

In all, some $100 billion in buildings would be placed at risk along the California coast. The flooding could affect roads, hospitals, schools, emergency facilities and railroads. Wetlands and natural ecosystems also could be destroyed by changes in sea level.

Potential costs in Orange County, part of the estimated $17 billion total, include $14 billion in residential costs, $2.3 billion for commercial facilities, $610 million for industrial facilities, and $110 million each for educational and religious facilities. Because of these the actual market costs could be several times higher. Even places that are not directly subject to flooding could suffer erosion because of sea level rise. And sea level rise in Northern California could have troubling effects in the south. Increased salinity in the California delta could reduce supplies of drinking water piped to Southern California.

The report draws a distinction between mitigation measures to reduce the effects of global warming, such as reductions in greenhouse gas emissions, and “adaptations” to coming changes along the coast -changes that will be inevitable, even if we reduced greenhouse gas emissions to zero tomorrow.

California is already moving to cut greenhouse gas emissions. But a variety of stakeholders, including those involved in everything from shipping, boating and recreation to habitat conservation, must come together. The choices we make in the next few years are going to have a big bearing on whether this plays itself out or not, both in terms of mitigation- greenhouse gas reduction -and in terms of adaptation.