Rising to the challenge of sea-level rise

Rising to the challenge of sea-level rise
Cliffside erosion and ocean waves at Point Loma tidepools in San Diego, California. Courtesy photo

ENCINITAS — The erosive powers of both nature and man meet at the coastline.

Not just erosion, but policy and planning, should shape the shores of San Diego County moving forward.

To continue that future-looking process in public, Encinitas City Hall hosted a workshop on sea-level rise featuring six guest speakers on May 8.

Crystal Najera, Climate Action Plan Program Administrator for Encinitas, listens to an audience member’s question. Photo by Carey Blakely

Current research predicts an acceleration in sea-level rise around 2050 or 2060 that could have far-reaching effects on the coast and its inhabitants. There are varying estimates, but studies predict a rise of about 1 to 2 feet by 2050 and 3 to 6.5 feet by 2100.

Higher sea level could result in increased erosion of beaches and bluffs, sewer spills, soil contamination, structure damage and more. Flooding is expected to come from both erratic rainstorms that could breach lagoon shores and powerful storm surges generated at sea. The combination could be disastrous, with coastal roads and structures overrun with water and rendered inaccessible.

Encinitas and other coastal municipalities need to identify what they will do to mitigate these impacts and adapt to environmental change as they look toward the next 30 years and beyond. “There’s a moment to take a breath now, but there will be a moment when we’ll have to act,” said workshop presenter Laura Engemen. She is the Program Director at the Center for Climate Change Impacts and Adaptation at the Scripps Institution of Oceanography.

Crystal Najera, Climate Action Plan Program Administrator for Encinitas, explained at the workshop how sea-level rise can be attributed to two main factors: the melting polar-ice caps and other ice sheets as well as increasing sea temperatures. When water is heated, it expands, causing an increase in volume or a “rise.”

The increased heat comes, in large part, from the release of greenhouse gases into the atmosphere, most commonly emitted by burning fossil fuels like oil, natural gas and coal. Humans could potentially reduce the degree of sea-level rise and its associated effects if we decrease our greenhouse gas emissions, but there are a lot of unknowns.

What should Encinitas do to prepare for an increasing sea level and the flooding and erosion it could bring? What are the expected financial impacts? Does sand nourishment (adding sand to beaches) work and for how long?

The Coast News will delve further into these questions next week.

 

 

 

5 Comments
  1. Richard Wright 6 months ago

    Sea level changes along the California coast have been measured by NOAA tide stations for more than 100 years. The two nearest tide stations are at Scripps Pier in La Jolla, and on San Diego Bay. Both stations indicate that sea levels are rising over time at a very modest rate.

    The long term average sea level rise at Scripps Pier, for the period 1924 to 2016, is only 2.17 millimeters per year. This equates to .71 foot of increase over a 100 year period. The long term average sea level rise at San Diego Bay, for the period
    1906-2017, is also only 2.17 millimeters per year, which again equates to a .71 foot increase over 100 years. This translates to about 8.5 inches of sea level over 100 years.

    City staff, and City elected officials, should give most weight to the factual, historical tide station data, along with giving some consideration to speculative estimates of future sea level rise provided by some computer programs. Computer output is not data. It is only computer output. Our City should be able to deal with 8.5 inches of sea level rise over the next 100 years.

    Also, the rate of sea level rise, as objectively measured at local tide stations, does not indicate any acceleration in sea level rise over recent decades. The sea level rise did spike up during the most recent El Nino period, but has since dropped back to a lower, more typical level.

  2. Rich Wright 6 months ago

    From this article, it appears officials are making decisions based on speculative predictions regarding accelerated sea rise.
    Rather than giving weight to speculation, officials should base their decisions on actual objective historical data about sea level rise.

    The nearest NOAA tide station along our coast is at the Scripps Pier in La Jolla. The historical data, from 1924-2016, indicates an average sea level rise of 2.17 mm per year, which equates to .71 feet per 100 years. This historical data shows a relatively steady rise over the decades, with no recent accelerated sea level rise. The graph of the data for Scripps Pier does show a brief upward spike during the last El Nino period, and then a considerable drop down to the most recent posted data.

  3. Glen Johnson 6 months ago

    From the previous response we can see that denial is thriving. The panel of experts have been studying this for decades and have large quantities of historical data. Climate change and sea level rise are happening, the only question is how soon will it be recognized.

    I attended that meeting and listened carefully. The common estimate is for sea level rise of between 1 and 4 feet over the next 80 years. One expert said that it could be as much as 5.5 feet. None of the experts had a crystal ball that could see into the future and precise historical data is lacking as they didn’t have GPS and computer technology and goverenment grant money 100 years ago.

    However, the tipping point seems to be that at 2 feet rise it will be time to move the coastal railroad line, This might not be for 50 or 60 years.

    The current strategy is to rely on sand replenishment projects to enlarge the beaches and help slow bluff erosion. Some historical data suggests that bluff failures, though infrequent, have been dramatic.

    Another unknown is the impact of some storm surge at high tide or a hurricane or tsunami that sweeps across the Pacific. One such event could ruin all the plans that are being made.

    The only thing that is constant is change.

    • Author
      Carey Blakely 6 months ago

      Thanks for weighing in, Glen and Richard. I just want to clarify to you and other readers that the sea-level rise estimates I put in the article came from the graph that Adam Young presented at the workshop. It showed the mean sea-level rise predictions of four studies. One Department of Defense (DoD) estimate was for a sea-level rise of 3.28 feet by 2100, while a different DoD study predicted 6.56 feet by 2100. A third study shown on that graph that was attributed to CCC (which I’m assuming is the California Coastal Commission) projected a rise of 5.48 feet by 2100. The fourth one, RCP (which might stand for Representative Concentration Pathways, but I’d have to verify with Young) was 4.5 feet.

      I’ll be following up with a second, more in-depth article on the subject next week and will attempt to get more input and estimates on sea-level rise from experts then. Thanks!

  4. Rich 6 months ago

    The historical data from the two local NOAA tide stations is available online to the public. It speaks for itself. At the Scripps Pier data page, it can be observed that the most recent posted sea level measurements are actually lower than most of the measurements recorded during the 1990-2000 period. Encinitas’ coastline survived the 1990s, so it should be able to survive the current sea levels we are experiencing.

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