A new study has been published that has found that the rate of sea level rise is much worse than previously thought, having tripled in pace since 1990. Before 1990, the oceans were rising at an average rate of 11 millimeters (0.43 inches) per decade, but between 1993 and 2012, that rate increased to 31 millimeters (1.22 inches) per decade.
"We have a much stronger acceleration in sea level rise than formerly thought," explains study lead Sönke Dangendorf, with Germany’s University of Siegen. "The sea level rise is now three times as fast as before 1990."
The study, an international effort involving researchers from Germany, Spain, France, Norway and the Netherlands, says that the cause of the increase is the added meltwater being released into the seas from the ice sheets in Greenland and Antarctica: prior to that, most of the meltwater was from smaller glaciers throughout the world.
Studying long-term sea level increases is a difficult task, due to satellite records only going back to the early 1990s. Researchers have since been working to piece together what the rates were before that, representing both the overall average and regional rates, based on older recording methods, and accounting for geological and gravitational variables that previously skewed the data. This new study endeavored to correct these factors, and found that previous studies were underestimating sea level rise rates because of them.
While a portion of sea level rise is due to natural factors, the brunt of the current trend is undoubtedly due to the impact of human activity on the environment. However, Dangendorf is confident that we may be able to mitigate our own impact on the severity of sea level increases:
"Sea levels will continue to rise over the coming century, no matter whether we will adapt or not, but I think we can limit at least a part of the sea level rise. It will further accelerate, but how much is related to how we act as humans."