There’s no need to panic about the rising sea level

From major news media to Florida’s real estate sellers to NASA, lots of people seem to be worried about the rising sea level. Most blame it on global warming. Yet the sea level has been rising at a steady rate, between 1 and 2 millimeters per year, regardless of ocean temperature. The sea level rose when ocean temperature increased by 0.5 degree Celsius between 1920 and 1940, but rose at the same constant rate when ocean temperature cooled between 1945 and 1975. The sea level did not accelerate or decelerate, as some might expect — meaning that the rise of the sea level does not depend on ocean temperature, much less on the atmospheric carbon dioxide (CO2) level.

Basic physics teaches that sea water must expand as temperature rises. I believe that evaporation of sea water offsets thermal expansion. The evaporated water causes an increase in precipitation, which turns into snow and ice as it rains over the continent of Antarctica.

{mosads}But if precipitation offsets evaporation, more or less 100 percent, the net effects are, of course, zero. What, then, causes the sea level to rise?

It is all a matter of time scales. Antarctica gains ice on a time scale of years. The sea level rises because of the slow melting of glaciers and ice sheets, on a time scale of centuries, that add more water to the ocean.

The reason for the melting­ is that it is warmer now than it was 12,000 years ago, at the end of the most recent ice-age glaciation. There is nothing we can do to stop this slow melting. The sea level will continue to rise at about the same rate, no matter what we do.

Former vice president Al Gore has been hyping the rising sea level, ably assisted by former NASA climate scientist Dr. James Hansen. Don’t forget, it was Gore who famously pronounced, in the 2012 presidential campaign, “A zebra doesn’t change its spots [sic].” And sure enough, Gore is back, busily inundating the Statue of Liberty and much of New York City with his prediction that, because of global warming, melting ice could cause the sea level to rise 20 feet.

Recently, professor Michael Mann, director of the Penn State Earth System Science Center, has taken up this alarmist cause in the false belief that human activities are causing the sea level to rise. Mann, of course, is notorious for helping to develop the “hockey stick graph,” asserting that Earth in the 20th century is warmer than it was 1,000 years ago during the medieval warm period. All of these alarmists preach that the emission of CO2 is responsible for the observed sea level rise.

Their forlorn hope is that restrictions on fossil fuel burning will slow down the rising sea. Untold billions of dollars have been wasted, especially in Europe, following up on this false belief.

I have found that the notion has become common wisdom among many scientists ­and, of course, the mainstream media and general public.

Even some of my friends, scientists who are skeptical about human-caused (anthropogenic) global warming, have difficulty at first accepting my hypothesis on the sea level rise. However, you cannot argue against the logic or data associated with rising sea level. The logic is explained above; the data come from hundreds of tidal gauges throughout the world, many of which have been in operation for over a century.

There is one exception to my discussion: tidal gauges measure sea level with respect to the shoreline. If pumping of groundwater is excessive, the shoreline moves downward. (The technical word is subsidence.) In that case, the tidal gauges would indicate an enhanced rise in sea level.

What might we expect in the future? People want to know what the sea level will be in, say, the year 2100. Well, if the sea level continues to rise at the same average rate, as we expect, it will be higher by about six inches­ — no big deal! That’s a long way from the crazy numbers that Al Gore has been peddling.   

S. Fred Singer is professor emeritus of the University of Virginia and a senior fellow with The Heartland Institute. He was among the first prominent scientists speaking out against global warming alarmism. An atmospheric and space physicist, he headed the U.S. Weather Satellite Service [now part of NOAA], founded the Science and Environmental Policy Project and the Nongovernmental International Panel on Climate Change.