June 20, 2015

What Will Happen to Surf Spots After Sea Level Rise?

sea_level_rise_surf_spots
Surf spots dependent on the bottom tension of reefs may see some drastic changes in the future caused by sea level rise. South Australia. Photo: Stu Gibson.

The notion of “sea level rise” is often the first thing mentioned when discussing climate change. While opinions may vary on what causes climate change and how it will affect our planet, certainly no one can refute the cold hard data offered from a wide variety of sources – temperatures on a global scale are getting warmer as the rate of carbon emissions are simultaneously increasing. Regardless of the cause, experts and scientific research warn that the sea levels will rise as much as 4 – 6 feet by the end of the century. While this will most likely have a serious impact on humanity, every surfer just wants to know what will happen to the waves and surf spots?

The Waves

Waves are basically caused by winds blowing on the surface of the water. The winds from low pressure systems (storms) produce the biggest waves, and it’s pretty obvious that climate change will affect those storms. Recently, the holy grail of scientific journals – Nature, published a research article that found “an agreed projected decrease in annual mean significant wave height (HS) over 25.8% of the global ocean area.” That’s awful! The study found that the greatest decreases were noted over the North Atlantic, North Pacific, and Indian Ocean during the Northern Hemisphere winter months (January, February, and March). Unfortunately, the North Atlantic will see a decrease in mean wave height during all seasons. Ouch!

While the study notes the significant decreasing trend in swell heights over time, it also points out that there will be occasionally larger than usual singular swell events caused by weather extremes induced by climate change. In other words, extreme weather will likely produce some huge swells, but not as often as the century progresses.

Interestingly, the study does find that certain areas will have consistent and significant increases as well. The biggest increase will take place south of Australia and New Zealand, especially during the Southern Hemisphere winter months from July to September. The projected increase will be a solid 5 to 10% above current averages during peak winter months. Wow! This increased wave height is proposed from an increase in storm-caused west winds in the area. These increases in west winds will also lead to longer period swell and bigger wave heights in the Eastern Pacific during the Northern Hemisphere summer months. This is in response to the swells propagating away from the enhanced storm activity in the South Pacific.

What does all this mean? In the Pacific Ocean, the Northern Hemisphere winter swells will get smaller and less consistent as the Southern Hemisphere swells will increase in size and period. That means our pumping winter surf on the West Coast will slowly subside throughout the 21st century. But the summer south swells will be on fire! The East Coast and Europe will see the most notable decrease in surf in the world with a slow decline throughout the rest of the century. Meanwhile, the entire Southern Hemisphere will be pumping during the Austral Summer months from July to September until 2.1K!

The Surf Spots

Even most non-surfers know that the higher tide can affect the quality of some surf spots. Well, a sea level rise will be like a “permanent high tide.” Perhaps sustainablesurf.org puts it best by saying “this sea level rise will result in the loss and destruction of many surf breaks world-wide, because while projected sea level rise happens on a 100-year timescale the geologic processes that form surf breaks happen on a 1000-year timescale.”

Essentially, this means that waves at sandy beach breaks like the ones at Huntington Beach, CA or the Outer Banks in North Carolina are likely to retain their same basic forms as they approach the shore. Sandbars often change daily almost everywhere in the world, and will likely adjust to the increased sea level heights very quickly. It’s the reefs and points that are in trouble. These types of waves break on rock and stone that’s either not going to erode in our lifetime, or be deposited by river systems fast enough. A good example brought forth by sustainablesurf.org states that “it is unlikely that San Mateo Creek will be able deposit cobblestones at Trestles fast enough to keep up with sea level rise in the next 100 years.”

Of course, breaks that are good at high tide will likely break more often. While low tide only breaks like Supertubes in Los Angeles are doomed to disappear completely! There’s also going to be a lot of new surf spots created as waves break on new areas of reefs that haven’t seen swell action. Some of these spots may be unorganized and difficult to surf, similar to newly formed reefs found on the Big Island of Hawaii. While others may actually get better like the earthquake altered reefs in Indonesia and Chile. Despite all this, researchers and experts agree that the overall effect of advancing seas is likely to be more destructive than constructive. Only time will tell!

  • sea-level-rise
    Beach breaks like Huntington Beach in SoCal are not likely to change with rising sea levels as constantly shifting sandbars will adjust to the slow rise of the sea. Photo: ocregister.com

 

 

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