Sitting in the ocean means experiencing waves, changes in temperature, variations of color, textures between your toes, the giving over to the motion that gently (and sometimes not so gently) propels you in directions that you have little control over. Witnessing the tides-sometimes “oh so low” and often “oh! too high” is astonishing in it extremes. How can we measure something so alive and ever changing?
“If you could take planet Earth and move it out into deep space so that the sun, moons and other planets did not affect it and there were no temperature variations worldwide, then everything would settle down like a still pond. Rain and wind would stop, and so would the rivers. Then you could measure sea level accurately. If you did this, the level of the ocean’s water projected across the entire planet would be called the geoid.” This is the reality from a simple web search on measuring sea level rise from WikiHow.
MacMillan Arctic Expedition in 1926. Original photo NOAA Photo Library.
Clearly measuring sea level rise is not an easy or exact science because of all of the variables that our dynamic, powerful beautiful ocean embodies. To complicate issues, when measuring sea level rise scientist must include movement of the land in and around the water. “Because the heights of both the land and the water are changing, the land-water interface can vary spatially and temporally and must be defined over time. Depending on the rates of vertical land motion relative to changes in sea level, observed local sea level trends may differ greatly from the average rate of global sea level rise, and vary widely from one location to the next,” according to NOAA. There are graphs, assessments, and a slew of documents from prestigious institutions, some confusing and some, thank god, worth reading for their simplicity and clarity.
For a very long time, sea level rise was measured with a tidal gauge, a simple tool that works by measuring the height of water relative to a fixed point on land. Today satellite equipment has taken over but fancy equipment doesn’t mean that data can ignore the variables that make sea level rise so difficult to predict. The important fact is, that data over a long period of time tells us that the sea is rising and that without cuts in emissions, it will keep rising with catastrophic results to many coastal communities across the globe.
Women Working for Oceans invites you to explore sea level rise at Water Rising: The Impact on Humanity on April 6th. National Geographic Photographer, George Steinmetz, will take the audience on a photographic look at how sea level rise affects coastal communities, rich and poor, around the world. Erika Spanger-Seigfried, from the Union of Concerned Scientists, will review the basic concept behind warming oceans, rising sea levels and human’s contribution to this critical global issue.
To read more about sea level rise, here are some websites that are easy to understand and thoughtful in their presentation. At Skeptical Science, you can even choose “basic” or “intermediate” language around the topic of sea level rise. Yale Universities report by Nicola Jones reviews data and questions what we really do know about sea level rise covering topics of long and short-term trends in data, melting polar ice sheets and governmental reports. Contributor to the article and sea level researcher at the University of Texas, Don Chambers, adds “I always tell people if they live under 3 feet above sea level, they should be worried about the next 100 years,” says Chambers. “We probably can adapt to a certain extent. The problem is that we’re not planning for it.”
NOAA Photo: Morgan McHugh