California Coastal Commission and Malibu Developer Clash Over Sea Level Rise Height Predictions

The California Coastal Commission, the City of Malibu and coastal developer at clashing over a new beach development on the Pacific Coast Highway. One of the major points of contention is estimates of how much the sea will rise by 2100.

The city approved the developer’s plan based on an old sea level rise estimate of 1.5 feet by the turn of the century. The Coastal Commission takes issue with that prediction, which it says will put the property at a greater risk of flooding.

An engineer the city used to evaluate the project approved the 1.5 foot estimate because that was the number the Coastal Commission included in its 2015 guidance document. The Coastal Commission says the engineer should have used its region-specific estimate and updated 2018 guidance.

The gap between the Coastal Commission and the engineer is enormous. The sea level rise estimate was increased to over five feet in 2018. According to an article in the Malibu Times, a Coastal Commission staff report said, “The difference is more than 4.65 feet, which is significant in determining the required setback, finished floor elevation, and safety of the proposed structure from extreme events and sea level rise.” The report also mentions that scientists are now estimating that the seas could rise anywhere from 3.3 feet to 10 feet by the end of the century.

Scientists are having a tough time predicting sea level rise precisely because humans continue to burn the fossil fuels that create the greenhouse gases that are causing global warming at an accelerated rate. If society continues on this track, even the most liberal predictions could turn out to be conservative, especially if the Greenland and Antarctic ice sheets melt faster and are destabilized to the point where land-based glaciers flow more rapidly into the sea.

The Malibu case is just one example where real estate developers and cities are relying on the most optimistic sea level rise estimates for new construction projects. Buyers shouldn’t trust that a developer or city has done its homework when they purchase a coastal property. Independent due diligence is required to make sure they’re fully informed regarding the risk of sea level rise flooding in the years to come.