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GOOD news for surfers, bad news for beach lovers—California’s waves are
getting bigger. Research has shown Atlantic waves growing over the past few
decades, but data for the Pacific has been patchy. Now Nicholas Graham from the
Scripps Institution of Oceanography in San Diego has used a collection of wind
speed data to back-calculate stormy wave heights for the past 50 years. He and
his colleagues found the biggest waves in southern California have grown by up
to 2 metres since 1948, making them about 35 per cent higher. Surprisingly, they
also found that wind directions have shifted to the south. That means waves are
crashing straight into the mainland instead of hitting the Channel Islands near
Los Angeles first, making them more likely to erode the shore. Graham says he
can’t be sure, but he thinks that global warming in the tropics is making the
storms stormier and the waves bigger (Bulletin of the American Meteorological
Society, vol 82, p 1869).