A data visualization released last week by NASA shows how much sea levels have risen in the three short decades its satellites have been tracking them. This has alarmed environmentalists and scientists around the world.
Sea level has risen more than 9 centimeters (about 3.5 inches) in those 30 years. This may not seem like much, just at arm’s length, but when these changes are visualized as water splashing through a window that looks like a ship, it starts to feel very real. For those of us trying to imagine these major changes in a more personal way, NASA says the animation “is meant to be viewed through a circle, using the visual metaphor of looking through a boat porthole and observing years of sea level rise.”
Sea level rise is one of the consequences of global warming caused by humanity’s greenhouse gas emissions. Since 1993, sea levels have been measured regularly by satellites that track microwave signals from the ocean surface and determine how long it will take them to return. From this, researchers can calculate and monitor sea surface elevation.
“We have a clear picture of recent sea level rise, and we can better predict how much and how fast the oceans will continue to rise,” explains Karen Saint-Germain, director of NASA’s Earth Sciences Division.
To make predictions, the data are fed into global climate models that try to reconcile the different elements of our planet’s surface conditions. In terms of sea level rise, these three decades of satellite observations are combined with more than 100 years of coastal tide gauge measurements, ice massif data, and, of course, rising greenhouse gas emissions.
Millions more are expected to be affected by rising sea levels that will cause coastlines to “disappear” unless emissions are drastically reduced to zero. The impact of all these heat-trapping emissions is now keenly felt by coastal communities around the world – not that they need to be reminded of the salty seas overflowing their threshold.
But synthesizing this data and making people around the world aware of what it all means is one of the problems underlying the climate crisis that will affect those who have contributed the least to global warming the most.
Although the atmosphere has long been Earth’s cozy blanket, the planet is now languishing under the weight of carbon dioxide emissions. And it is the oceans that have absorbed a whopping 90 percent of the heat that we humans have added to the system.
